Ruthenium complexes with dendritic ferrocenyl phosphanes: Synthesis, characterization, and application in the catalytic redox isomerization of allylic alcohols

DOI: 10.1002/chem.201406489

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Homogeneous Catalysis

Ruthenium Complexes with Dendritic Ferrocenyl Phosphanes:

Synthesis, Characterization, and Application in the Catalytic

Redox Isomerization of Allylic Alcohols

Paul Neumann,^[a]Hanna Dib,^[b]Alix Sournia-Saquet,^[b]Toni Grell,^[a]Marcel Handke,^[a]Anne-

Marie Caminade,^[b]and Evamarie Hey-Hawkins*^[a]

Abstract: An efficient system for the catalytic redox isomeri-

zation of the allylic alcohol 1-octen-3-ol to 3-octanone is pre-

sented. The homogeneous ruthenium(II) catalyst contains

a monodentate phosphane ligand with a ferrocene moiety

in the backbone and provides 3-octanone in quantitative

yields. The activity is increased by nearly 90% with respect

to the corresponding triphenyl phosphane ruthenium(II)

complex. By grafting the catalyst at the surface of a dendri-

mer, the catalytic activity is further increased. By introducing

different spacers between ferrocene and phosphorus, the in-

fluence on the electronic properties of the complexes is

shown by evaluating the electrochemical behavior of the

compounds.

Introduction

ous catalyst can be recovered by fractional distillation. Another

synthetic approach to overcome separation problems of ho-

mogeneous catalysts is the immobilization of the catalytic

entity onto solid materials such as inorganic solids (e.g., silica

and alumina), polymers, or nanoparticles.^[3,4c]These supported

catalysts are often insoluble (heterogeneous) and additionally

they may suffer from catalyst leaching due to metal–ligand

bond cleavage. An advantage of soluble polymers as support

is the even distribution of the active sites in the reaction

medium. Dendritic polymers are outstanding representatives

of such soluble macromolecules. Due to their step-by-step syn-

thesis, dendrimers display a well-defined and highly branched

molecular architecture with the functional groups located on

the surface in which they are easily accessible.^[9]Therefore, the

concentration and localization of the grafted catalyst can be

precisely controlled^[10]and the active sites are in close proximi-

ty to each other. The resulting high local catalyst concentration

may cause an empirical “positive dendritic effect”, an increas-

ing activity with increasing generation.^[11]Additionally, dendritic

catalysts are nano-objects that can be easily separated by pre-

cipitation or nanofiltration.

The transition-metal-catalyzed redox isomerization of allylic al-

cohols represents a useful and atom-economical synthetic pro-

cess en route to saturated carbonyl compounds.^[1]Due to the

well-known ability of transition metals to facilitate the migra-

tion of carbon–carbon double bonds, the allylic alcohol is

turned into an enol, which then readily isomerizes to the corre-

sponding carbonyl compound.^[2]Besides rhodium(I),^[3]rutheniu-

m(II) is predominantly used for this transformation.^[4]The main

effort in recent years is focused on more efficient catalytic sys-

tems promoting the reaction in short reaction times under

mild conditions.^{[1c,e,f,2f,5]}Monodentate ruthenium phosphane

complexes proved to be more reactive catalysts than various

bidentate analogues.^[1b]In particular, [(h⁶-p-cymene)RuCl₂(L)]

complexes with L being a monodentate phosphane ligand

(PPh₃or analogues) show high activities.^[4,6]We are particularly

interested in this reaction because it has already been applied

to numerous multi-step syntheses^[7]and also to metalloden-

dritic catalysts.^[8]In most industrial processes the homogene-

Herein, we report the preparation and structural characteri-

zation of new monomeric and dendritic ferrocenyl phosphane

ligands containing different spacers between ferrocene and

phosphane to investigate their influence on the catalytic activi-

ty of the complexes. These phosphanes served as monoden-

tate ligands in (h⁶-p-cymene)ruthenium complexes, which were

tested in the redox isomerization of allylic alcohols.

[a] P. Neumann, T. Grell, Dr. M. Handke, Prof. Dr. E. Hey-Hawkins

Institute of Inorganic Chemistry

Universitꢀt Leipzig

Johannisallee 29, 04103 Leipzig (Germany)

Fax: (+49)341-973-9319

E-mail: hey@uni-leipzig.de

Homepage: http://www.uni-leipzig.de/chemie//hh

[b] Dr. H. Dib, Dr. A. Sournia-Saquet, Prof. Dr. A.-M. Caminade

Laboratoire de Chimie de Coordination du CNRS

205 route de Narbonne, BP 44099

31077 Toulouse Cedex 4 (France)

Fax: (+33)561-5530-03

Supporting information for this article is available on the WWW under

http://dx.doi.org/10.1002/chem.201406489.

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To graft ferrocenyl phosphanes on the surface of phospho-

rus-containing dendrimers, a free phenol function at one cyclo-

pentadienyl ring is required, because only a phenolic OH

group is reactive enough to quantitatively substitute the termi-

nal PꢀCl bonds. Thus, the synthetic route for the monomeric

Results and Discussion

Synthesis of the ferrocenyl phosphanes

The branching step in the synthesis of phosphorus-containing

dendrimers is the quantitative substitution of the terminal Pꢀ compounds was slightly modified (Scheme 2) and 1 was treat-

Cl bonds by functionalized phenols.^[9a]Therefore, the ferrocenyl

phosphane requires a phenol function for the grafting to the

dendrimer. To mimic the phenol linker in the corresponding

monomeric (non-dendritic) ferrocenyl phosphanes, an anisole

moiety was introduced at the lower cyclopentadienyl ring

(Scheme 1).

ed with (4-bromophenoxy)(tert-butyl)dimethylsilane instead of

4-bromoanisole. The resulting complex 6 was treated either

with 1 equiv n-BuLi and chlorodiphenylphosphane to yield 7,

or with the corresponding functionalized triphenylphosphane

sulfides (bromophenyl-diphenylphosphane sulfide or 4’-bromo-

biphenyl-diphenylphosphane sulfide) to give 9a and 9b. De-

protection with tetra-n-butylammonium fluoride gave the

phenol-functionalized ferrocene derivatives 8, 10a, and 10b in

high yield and purity. Sulfur deprotection with activated Raney

nickel gave 11 a and 11 b in high yields.

The dendritic ferrocenyl phosphanes were constructed

through a divergent approach^[10]by grafting 8, 11 a, and 11 b

to different generations of phosphorus-containing dendrimers

G_x(x=1–3). Starting from the hexafunctional N₃P₃Cl₆core, the

dendrimers are built up generation by generation. The P(S)Cl₂

groups display the branching function in each generation.

Every step in this reaction sequence gives quantitative conver-

sion, which is a requirement in the synthesis of this kind of

dendrimers. Another advantage of these phosphorus-contain-

ing dendrimers is the possibility of monitoring the reaction

progress by ³¹P{¹H} NMR spectroscopy.

Scheme 1. Synthesis of the monomeric ferrocenyl phosphanes 3, 5a, and

5b starting from 1,1’-dibromoferrocene (1). i) nBuLi, ZnCl₂, [Pd(PPh₃)₄], 4-bro-

moanisole; ii) nBuLi, PClPh₂, ꢀ788C; iii) nBuLi, ZnCl₂, [Pd(PPh₃)₄], a) 4-bromo-

phenyl-diphenylphosphane sulfide, b) 4’-bromobiphenyl diphenylphosphane

sulfide; iv) Raney nickel, toluene, 808C.

The grafting experiments were conducted with different

generations of phosphorus-containing dendrimers G_x(x=1–3)

as shown in Scheme 3 using a slight excess of ferrocenyl phos-

phane 8, 11 a, or 11 b with respect to the terminal PꢀCl groups

at the dendrimer. The reaction progress was controlled by

³¹P{¹H} NMR spectroscopy. The signal corresponding to the

The synthetic sequence starts with 1,1’-dibromoferrocene

(1), which was treated with 4-bromoanisole in a Negishi cross-

coupling reaction to form 2 (Scheme 1). Compound 3

can be obtained by treating 2 with nBuLi (1 equiv)

and then quenching the intermediate lithioferrocene

with chlorodiphenylphosphane. The ³¹P{¹H} NMR

chemical shift of 3 is located at d=ꢀ16.8 ppm. The

incorporation of a spacer between ferrocene and

phosphane involves an additional Negishi cross-cou-

pling. To avoid side reactions and complexation of

the phosphane substrate to the Pd⁰catalyst, the

functionalized phosphane was sulfur-protected prior

to the Negishi cross-coupling. The monomeric ferro-

cenyl phosphane sulfides 4a and 4b were obtained

and purified by using column chromatography. There

are numerous ways to reduce phosphane sulfides

like the reaction with LiAlH₄, Raney nickel, more elec-

tron-rich phosphanes, or various silanes. Here, acti-

vated Raney nickel produced the trivalent phos-

phanes 5a and 5b in high yields.

In the ³¹P{¹H} NMR spectra, the chemical shift

changes from d=43.0 ppm (R₃P=S) to about d= Scheme 2. Synthesis of the phenol-functionalized ferrocenyl phosphanes 8, 11 a, and

1

11 b starting from 1,1’-dibromoferrocene (1). i) nBuLi, ZnCl₂, [Pd(PPh₃)₄], (4-

ꢀ6 ppm (R₃P). Furthermore, the change in the J_CP

bromophenoxy)(tert-butyl)dimethylsilane; ii) nBuLi, PClPh₂, ꢀ788C; iii) TBAF·3H₂O, THF,

coupling constant of the quaternary carbon atoms in

0.5 h, RT; iv) nBuLi, ZnCl₂, [Pd(PPh₃)₄], a) 4-bromophenyl-diphenylphosphane sulfide, b) 4’-

the ¹³C{¹H} NMR spectrum proves the transformation

of 4a/b (¹J_CPꢁ88 Hz) to 5a/b (¹J_CPꢁ11 Hz).

bromobiphenyl-diphenylphosphane sulfide; v) TBAF·3H₂O, THF, 3 h, RT; vi) Raney nickel,

toluene, 808C; TBDMS=tert-butyldimethylsilyl, TBAF=tetra-n-butylammonium fluoride.

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Scheme 3. Synthesis of the dendritic ferrocenyl phosphanes 8-G₁, 11a-G₁, and 11b-G₁. The corresponding derivatives of G₂and G₃were synthesized under

similar conditions.

terminal phosphorus atom shifts from about d=63 (P(S)Cl₂) to

around 70 ppm for monosubstitution (P(S)Cl(Oꢀaryl)), and to

d=62 ppm for disubstitution (P(S)(Oꢀaryl)₂). After filtration

from Cs₂CO₃, the dendrimer was precipitated into a mixture of

n-pentane/diethyl ether (1:1). By reprecipitation the slight

excess of ferrocenyl phosphane derivative could be easily re-

moved. The dendritic ferrocenyl phosphanes 8-G_x, 11a-G_x, and

11b-G_x(x=1–3) were isolated in good-to-excellent yields (68–

99%, Scheme 3).

action of 3, 5a, and 5b with di-m-chlorobis[(h⁶p-cymene)chlor-

oruthenium(II)] in CH₂Cl₂followed by silica filtration

a

(Scheme 4). Upon complexation, a characteristic low-field shift

is observed in the ³¹P{¹H} NMR spectra (Dd ³¹P=35.6 ppm for

3!3-Ru; Dd=29.8 ppm for 5a/b!5a/b-Ru).

Similar reaction conditions were applied for the synthesis of

the dendritic ferrocenyl phosphane complexes.^[12]

Thus, the dendritic ligands 8-G_x, 11a-G_x, and 11b-G_x(x=1–

3) were treated with 0.5 equiv of di-m-chloro-bis[(h⁶-

p-cymene)chlororuthenium(II)] per terminal phosphane in

CH₂Cl₂at room temperature. ³¹P{¹H} NMR spectroscopy indicat-

ed full conversion after a few hours. Due to the size of the

dendrimers, purification through silica filtration could not be

applied. Alternatively the dendritic complexes were precipitat-

Synthesis of (h⁶-p-cymene)ruthenium(II) complexes

The heterobimetallic complexes 3-Ru, 5a-Ru, and 5b-Ru were

readily obtained in excellent yields at room temperature by re-

Scheme 4. Synthesis of the monomeric ruthenium complexes 3-Ru, 5a-Ru, and 5b-Ru (right) starting from the monomeric ferrocenyl phosphane ligands 3,

5a, and 5b. The dendritic complexes 8-G_x-Ru, 11a-G_x-Ru, and 11b-G_x-Ru (x=1–3, left) were synthesized under similar conditions from the dendritic ligands

8-G_x, 11a-G_x, and 11b-G_x.

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ed in n-hexane/CH₂Cl₂(4:1). The dendritic complexes 8-G_x-Ru,

11a-G_x-Ru, and 11 b-G_x-Ru (x=1–3) were obtained in good to

1

excellent yields (Scheme 4). The purity was confirmed by H,

³¹P{¹H}, and ¹³C{¹H} NMR spectroscopy showing neither free

phosphane nor the ruthenium precursor.

Structural characterization of selected ferrocenyl phosphane

sulfides, ferrocenyl phosphanes, and 5a-Ru

Single crystals of selected ferrocenyl phosphane sulfides (4a,

9b, 10a), ferrocenyl phosphanes (3, 11 a), and the ruthenium

complex 5a-Ru were obtained and studied by X-ray crystallog-

raphy. Selected bond lengths, distances, and angles are sum-

marized in Table 1.

Figure 1. Molecular structure of 3 (hydrogen atoms have been omitted for

clarity; ellipsoids are shown at 50% probability).

Table 1. Selected bond lengths [pm], angles [8] and distances [pm]^[a]for

3, 4a, 9b, 10a, and 11 a.

3

4a

9b

10a

11a

PꢀC

180.9(2)–

183.6(2)

–

202.7(2)–

205.6(2)

164.6(1)

163.9(1)

180.0(3)– 179.9(5)–

181.0(3)–

181.6(3)

196.2(2)

202.9(3)–

206.5(3)

182.8(3)–

185.9(3)

–

203.0(4)–

207.7(4)

(range)

P=S

181.5(3)

195.1(1)

182.7(5)

194.8(2)

FeꢀC

(range)

FeꢀCc1

FeꢀCc2

Cc1-Fe-Cc2

tilt

t (1)

t (2)

t (3)

t (4)

202.8(3)– 202.3(5)–

207.0(3)

164.2(1)

163.7(1)

205.8(5)

164.25(6) 164.37(8) 165.37(6)

164.03(6) 164.19(8) 164.86(6)

179.39(5) 178.27(4) 176.9(4)

179.24(4) 177.9(1)

ꢀ0.8(1)

3.4(1)

2.4(2)

8.9(1)

6.8(1)

–

1.3(2)

1.46(3)

10.4(2)

2.2(1)

44.4(1)

362.6(1)

3.5(1)

2.9(1)

16.06(9)

4.26(9)

–

3.4(2)

4.2(2)

12.7(1)

18.4(1)

–

75.6(1)

30.8(1)

–

p–p

394.8(2)

364.9(2)

358.5(1)

[a] Ring planes: Cp1=C(1–5), Cp2=C(6–10); Cc1and Cc2 are the centroids

of Cp1 and Cp2; tilt=dihedral angle between planes Cp1 and Cp2; t=

torsion angles: between (1) Cp1 and Cp2, (2) Cp1 and C₆H₄, (3) Cp2 and

C₆H₄. (4) C₆H₄and C₆H₄(biphenyl spacer torsion for 9b); p–p stacking

(distance of the centroids of parallel face-centered phenylene rings).

Figure 2. Molecular structure of 4a (hydrogen atoms have been omitted for

clarity; ellipsoids are shown at 50% probability).

atom in the phosphane sulfides (4a, 9b, and 10a) and phos-

phanes (3, 11 a) are arranged in a trigonal pyramidal geometry.

The fully protected ferrocene derivative 9b (Figure 3) crystal-

lizes in the orthorhombic space group P2₁2₁2₁with eight for-

mula units per unit cell. A nearly perfect syn arrangement of

the cyclopentadienyl substituents is shown by t (1) being

close to 08 (1.46(3)8); the torsion angle of the biphenylene

spacer (t (4)) is 44.4(1)8. The syn arrangement of 10a (Figure 4)

is further stabilized by an intramolecular hydrogen bond of the

phenol to sulfur (261.5(3) pm) that is not present once the

sulfur is removed (see 11 a, Figure 5). The molecular structure

of complex 5a-Ru shows the expected three-legged piano

stool arrangement around the ruthenium center (Figure 6).^[14]

In contrast to the ferrocenyl phosphanes (3, 11 a) and phos-

phane sulfides (4a, 9b, 10a), in the heterobimetallic rutheni-

um complex the 1,1’-substituted ferrocene displays an anti-ar-

rangement. Even though the solid-state structure can differ

from the structure in solution, such an anti-arrangement

would allow easy access to the catalytic site, in particular when

the heterobimetallic complex is grafted to the surface of the

dendrimers.

Despite the sterically demanding substituents at both cyclo-

pentadienyl rings, the ferrocenes show only marginal variations

in the FeꢀC distances and, consequently, small tilt angles of

ꢀ0.8(1) to 3.5(1)8. Unlike 3 (Figure 1), all ferrocene derivatives

display a syn arrangement of the cyclopentadienyl substituents

resulting in an eclipsed conformation (D_5hsymmetry, t (1)

1.46(3)–4.2(2)8). This conformation is mainly due to parallel

face-centered intramolecular p–p interactions between the

two phenylene rings directly bonded to the cyclopentadienyl

ligands with p–p distances of 358.5(1) to 364.9(2) pm, in line

with the range of such interactions.^[13]Due to steric interac-

tions in 4a the phenylene rings are bent resulting in a longer

p–p distance of 394.8(2) pm (Figure 2).

As indicated by the torsion angles t (2) and t (3), the phen-

ylene rings are rotated with respect to the Cp1 or Cp2 plane,

respectively (Table 1). Due to the direct linkage of the phos-

phane to the ferrocene moiety, such p–p interactions are not

present in 3 (Figure 1).

Therefore, a synclinal eclipsed conformation of ferrocene is

observed in the solid state. The substituents at the phosphorus

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Figure 6. Molecular structure of 5a-Ru (hydrogen atoms, n-hexane, and tolu-

ene molecules have been omitted for clarity; ellipsoids are shown at 50%

probability). One cyclopentadienyl ring and the p-cymene ligand are disor-

dered (presented here as “ball-and-stick”).

Figure 3. Molecular structure of 9b (hydrogen atoms have been omitted for

clarity; ellipsoids are shown at 50% probability).

Table 2. Selected bond lengths [pm], angles [8] and distances [pm]^[a]for

5a-Ru.

5a-Ru

Fe-C

(range)

P-C

(range)

Fe-Cc1

Fe-Cc2

Cc1-Fe-Cc2

tilt

202.1(6)–

205.1(5)

181.9(5)–

184.8(5)

163.0(0)

163.8(0)

170.23(6)

2.2(4)

Ru-Cl1

Ru-Cl2

Ru-P

Ru-Cc3

Cl1-Ru-Cl2

Cl1-Ru-P

Cl2-Ru-P

Cc3-Ru-Cl1

Cc3-Ru-Cl2

Cc3-Ru-P

240.8(2)

240.0(1)

235.1(1)

179.6(1)

89.91(6)

87.95(5)

86.13(5)

131.34(5)

126.87(4)

121.03(4)

t (1)

t (2)

154.7(7)

28.1(4)

t (3)

2.3(2)

Figure 4. Molecular structure of 10a (hydrogen atoms other than OꢀH have

been omitted for clarity; ellipsoids are shown at 50% probability); dotted

line: Intramolecular S···H bond (261.5(3) pm).

[a] Ring planes: Cp1=C(1–5), Cp2=C(6–10); Cc1and Cc2 are the centroids

of Cp1 and Cp2; tilt=dihedral angle between planes Cp1 and Cp2; t=

torsion angles: between (1) Cp1 and Cp2, (2) Cp1 and C₆H₄, (3) Cp2 and

C₆H₄.

Electrochemistry

The monomeric and dendritic ligands and complexes were in-

vestigated electrochemically to evaluate the influence of the

spacer on the Fe²⁺/Fe³⁺and Ru²⁺/Ru³⁺redox processes and,

therefore, on the electron density of the catalytic center. The

square-wave voltammograms (only oxidation processes were

recorded) of the ferrocenyl phosphanes 3, 5a, and 5b

(Figure 7, top) indicate that the Fe²⁺oxidation potential is

shifted significantly to lower potentials (from 0.65 in 3 to

0.54 V in 5b) with increasing spacer length. The larger the dis-

tance of the electron-rich phosphane, the easier it is to oxidize

the ferrocene unit. This spacer effect is also present in the den-

dritic ferrocenyl phosphanes 8-G_x, 11a-G_x, and 11b-G_x(x=1–3,

see the Supporting Information).

Figure 5. Molecular structure of 11 a (hydrogen atoms other than OꢀH have

been omitted for clarity; ellipsoids are shown at 50% probability).

The bond lengths and angles (Table 2) compare well with

those determined for similar monodentate ruthenium phos-

phane complexes.^[5]The cyclopentadienyl torsion angle (t (1)=

154.7(7)8) indicates a conformation close to anticlinal eclipsed

(ideal value: t=1448) and the ferrocene moiety shows minor

distortion (Cc1-Fe-Cc2<1808).

In addition, the monomeric and dendritic ferrocenyl phos-

phanes show a second, irreversible oxidation process at 1.0–

1.2 V that can be assigned to the P^III/P^Voxidation. The phos-

phane oxidation wave is also dependent on the spacer and de-

creases in intensity with increasing spacer length (Figure 7,

top). The square-wave voltammograms (see the Supporting In-

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Table 3. Cyclic voltammetry data of ruthenium(II) complexes.^[a]

Entry

Compound

E_1/2/[V]

Fe²⁺/Fe³⁺

E_1/2/[V]

Ru²⁺/Ru³⁺

[b]

1

2

3

4

5

6

7

8

3-Ru

5a-Ru

5b-Ru

8-G₁-Ru

8-G₂-Ru

8-G₃-Ru

11a-G₁-Ru

11a-G₂-Ru

11a-G₃-Ru

11b-G₁-Ru

11b-G₂-Ru

11b-G₃-Ru

0.46

0.42

0.54

0.55

0.52

0.50

0.51

0.48

0.47

0.46

–

1.15

1.14

[b]

–

1.23

1.16

1.14

1.16

1.14

1.12

9

10

11

12

[a] 0.1m CH₂Cl₂/[n-Bu₄][PF₆], GC working electrode/SCE reference elec-

trode, scan rate=200 mVs^ꢀ1. [b] Irreversible oxidation process; CV data

of the ferrocenyl phosphanes are given in the Supporting Information.

Theoretical considerations

DFT calculations were conducted on the ferrocenyl phos-

phanes 3, 5a, and 5b to investigate the effect of the spacer

length on the Fe²⁺/Fe³⁺redox potential (Figure 8).

Geometry optimizations on several different conformers,

considering the rotation of the ferrocene unit as well as the

phenylene or biphenylene spacers and phenyl substituents

(Figure 8) suggest an anti arrangement of the cyclopentadienyl

substituents for 3 (no spacer), whereas 5a and 5b clearly

prefer a syn arrangement with an eclipsed ferrocene conforma-

tion. This difference is presumably due to attractive p–p inter-

actions between the spacer and the anisole moiety of the

lower cyclopentadienyl ring. Interestingly, in the case of com-

pound 5a, a close P···O distance is observed, which could

point to an intramolecular pnicogen bond causing a further

stabilization of this molecule (dashed line, Figure 8).^[15]The cal-

Figure 7. Top: Square-wave voltammetry (positive mode) of 3, 5a and 5b;

GC working electrode versus SCE reference electrode (f=20 Hz, amplitu-

de=20 mV, step=5 mV); Bottom: cyclic voltammetry of 3 and 8-G_x(no

spacer, x=1–3); 0.1m THF/[n-Bu₄][PF₆]; 3: GC working electrode; 8-G_x: Pt

working electrode versus SCE reference electrode (scan rates=100–

200 mVs^ꢀ1). GC=glassy carbon, SCE=saturated calomel electrode.

formation) as well as the cyclic voltammograms of the dendrit-

ic ferrocenyl phosphanes 8-G_1–3(no spacer) show an intensity

decrease with growing dendrimer generation (glassy carbon

(GC) working electrode) and even disappearance (Pt working

electrode) of the phosphane oxidation process (Figure 7,

bottom). Thus, a generation effect as well as an electrode ad-

sorption effect is assumed. Due to the large increase in size

from generation 1 to 3, the interaction between the molecules

is decreased, however, this effect is not observed for the den-

dritic ferrocenyl phosphanes with phenylene (11a-G_x) and bi-

phenylene spacer (11b-G_x).

The cyclic voltammograms of the ruthenium complexes

show two independent one-electron redox processes that can

be assigned to the redox pairs Fe²⁺/Fe³⁺and Ru²⁺/Ru³⁺

(Table 3).

All ruthenium(II) complexes show a fully reversible one-elec-

tron redox process for Fe²⁺between 0.42 and 0.55 V. The

spacer has a strong impact on the electronic properties of fer-

rocene; the half-wave potential is lowered with increasing

spacer length and dendrimer size. Compounds 3-Ru and 8-G₁-

Ru show an irreversible oxidation of Ru²⁺, whereas a reversible

process is observed for higher dendrimer generations. The

half-wave potential for Ru²⁺/Ru³⁺is similar for the phenylene

and biphenylene spacer.

Figure 8. Optimized structures for the most stable conformers of 3, 5a, and

5b (for more detailed information see the Supporting Information).

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culated energy difference (DG) between the most stable con-

former and its positively charged analogue is listed in Table 4.

The trend of a decreasing redox potential (DE⁰) with increas-

ing spacer length matches well with the findings in the elec-

trochemical experiments. Most likely, an extended conjugated

spacer facilitates delocalization of the positive charge, thus fa-

entry 3), 11a-G₁-Ru (entry 5), and 11a-G₂-Ru (entry 7), indicat-

ing that the reaction velocity is more dependent on tempera-

ture than on catalyst concentration. Compared to the mono-

meric catalyst 5a-Ru, the dendritic catalysts show much higher

catalytic activities under similar conditions (same quantity of

ruthenium) with turnover frequencies up to 1714 h^ꢀ1(Table 5,

entry 5). The 1st generation dendrimer is more active than the

2nd or 3rd generation dendrimer, thus, no “positive dendritic

effect”^[11]could be observed. To further explore these findings,

and to have a better comparison with complexes 3,5-Ru as

well as 8,11b-G_x-Ru (x=1–3), the catalyst loading was kept at

0.25 mol% Ru and the temperature was slightly decreased to

608C.

cilitating the oxidation of Fe²⁺

.

Table 4. Calculated DG values of neutral and positively charged most

stable conformers of 3, 5a, and 5b.

DG

[kJmol^ꢀ1

Increasing

spacer

DDG

[kJmol^ꢀ1

DE⁰

[kJmol^ꢀ1

]

[a]

[b]

[c]

]

The homogeneous allylic isomerization utilizing ruthenium(II)

complexes requires the use of a base.^[4d,16]As a poorly soluble

base is used for activation,^[17]an induction time is observed

that corresponds to the formation of the active species (Fig-

ure 9).^[4d]To minimize this effect for better comparability, the

3

500.14

491.24

488.63

3–5a

8.9

2.6

5.8

4.8

5a

5b

5a–5b

[a] DFT BP86-D(RI)/def2-TZVP. [b] Gibbs free energy differences between

DG from DFT calculations. [c] DE⁰between the oxidation potentials ob-

tained from square-wave voltammetry (Figure 7, top; for comparison

given in kJmol^ꢀ1: 1 V=1 eV=96.485 kJmol^ꢀ1).

Catalytic tests

The ruthenium(II) complexes were employed in the redox iso-

merization of the model substrate 1-octen-3-ol. Several mono-

dentate ruthenium(II) phosphane complexes have been investi-

gated and optimized for the redox isomerization of allylic alco-

hols.^[4d,6]Based on the optimization studies by Cadierno

et al.,^[4d]including different catalysts, solvents, temperatures,

bases, as well as substrates, we optimized the conditions for

5a-Ru and 11a-G₁-Ru (Table 5).

Using 1 mol% of the monomeric catalyst 5a-Ru at 708C re-

sults in full conversion after 20 min (Table 5, entry 1). By de-

creasing both catalyst loading (0.5 mol%) and temperature

(408C) the catalytic activity of 5a-Ru dropped rapidly (Table 5,

entry 2). If the temperature is kept at 708C and the catalyst

loading is further decreased to 0.25 mol% Ru, very high activi-

ties could be achieved for the complexes 5a-Ru (Table 5,

Figure 9. Plot of conversion versus time: Redox isomerization of 1-octen-3-ol

catalyzed by 5a-Ru, 11a-G_1–3-Ru, and PPh₃-Ru; monitored by GC-MS (uncor-

rected areas); conditions: 4 mmol 1-octen-3-ol; 0.25 mol% Ru and

0.625 mol% Cs₂CO₃in DCE, 608C (preheating 5 min); PPh₃ꢀRu=[(h⁶-p-cyme-

ne)RuCl₂(PPh₃)].^[18]

catalyst was preheated with Cs₂CO₃in solution for 5 min at

608C prior to substrate addition. Compound 5a-Ru still shows

good performance and converts 1-octen-3-ol in 1 h (Table 5,

entry 4). It should be noted that unexpectedly the 2nd and 3rd

generation dendritic catalysts are only poorly soluble in THF at

608C, but highly soluble in 1,2-dichloroethane (DCE). Although

THF usually gives faster conversion of 1-octen-3-ol, DCE was

employed here to compare the catalytic activities of all com-

plexes (Table 6).

Table 5. Results of the catalytic redox isomerization of 1-octen-3-ol (in

THF).^[a]

Entry

Catalyst

[mol%]

Ru

T

[8C]

t

Yield

[%]^[b]

TOF

[c]

[min]

[h^ꢀ1

]

1

2

3

4

5

6

7

5a-Ru

11a-G₁-Ru

11a-G₂-Ru

1.00

0.50

0.25

70

40

70

60

70

60

70

20

180

25

60

14

100

98

300

67

960

400

1714

600

The monomeric complexes (Table 6, entries 1–3), as well as

the dendritic complexes of generation 1 (entries 4–6), 2 (en-

tries 7–9), and 3 (entries 10–12), show good-to-high activities

in the conversion of 1-octen-3-ol to 3-octanone, with the den-

dritic catalysts clearly exhibiting higher activities than their

monomeric analogues. As the catalytic activity does not in-

crease with increasing generation of the dendrimers, no “posi-

tive dendritic effect”^[11]could be observed.

100

40

18

1333

[a] Redox isomerization of 1-octen-3-ol to 3-octanone; 4 mmol 1-octen-3-

ol; 4 mL THF; entries 1, 2, 3, 5, 7: 0.75 mol% Cs₂CO₃; entries 4, 6:

0.625 mol% Cs₂CO₃and 5 min preheating catalyst and base at 608C.

[b] Determined by GC-MS; [c] Turnover frequencies (mol product/(mol

catalystꢁtime)) were calculated at the time (t) indicated in each entry.

However, the higher catalytic activity of the dendritic cata-

lysts can be explained by a “multivalency effect”.^[19]The larger

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between ferrocene and phosphorus resulting in different elec-

trochemical behavior as well as catalytic activities. In particular,

compound 5a-Ru (phenylene spacer) showed increased activi-

ty compared to the triphenyl phosphane complex.

Table 6. Results of catalytic tests under optimized conditions (in DCE).^[a]

Entry

Catalyst

t

Yield

[%]^[b]

TOF

[h^ꢀ1

]

[c]

[0.25 mol% Ru]

[min]

The catalytic activity could be even further increased by

grafting the ferrocenyl phosphane derivatives to the surface of

phosphorus-containing dendrimers. Additionally, these com-

pounds containing a redox-active ferrocene moiety are highly

suitable for redox-switchable catalysis, which is part of the cur-

rent research.^[20]

1

2

3

4

5

6

7

8

3-Ru

5a-Ru

5b-Ru

8-G₁-Ru

11a-G₁-Ru

11b-G₁-Ru

8-G₂-Ru

11a-G₂-Ru

11b-G₂-Ru

8-G₃-Ru

11a-G₃-Ru

11b-G₃-Ru

PPh₃-Ru^[d]

220

90

130

100

60

90

120

60

200

120

50

220

170

100

109

267

185

240

400

267

200

400

120

200

480

109

141

9

10

11

12

13

Experimental Section

General considerations

For moisture- or air-sensitive compounds, the reactions were con-

ducted under nitrogen atmosphere using standard Schlenk tech-

niques. Toluene, n-hexane, THF, and CH₂Cl₂were dried in an MB

SPS-800 Solvent Purification System. 1,1’-dibromoferrocene,^[19]4-

bromo-(tert-butyldimethylsiloxy)benzene^[22]and the dendrimers G₁,

[a] Redox isomerization of 1-octen-3-ol to 3-octanone; 4 mmol 1-octen-3-

ol; 4 mL DCE; 0.625 mol% Cs₂CO₃and 5 min preheating catalyst and

base at 608C. [b] Determined by GC-MS. [c] Turnover frequencies (mol

product/(mol catalystꢁtime)) were calculated at the time (t) indicated for

each entry. [d] [(h⁶-p-cymene)RuCl₂(PPh₃)] as reference compound,^[18]for

more detailed information see the Supporting Information.

[23]

G₂, and G₃were synthesized according to literature procedures.

Ferrocene, n-BuLi, 1,1,2,2-tetrabromoethane, PClPh₂, di-m-chloro-

bis[(p-cymene)chlororuthenium(II)] are commercially available and

were used without further purification. The synthesis and charac-

terization of 4-bromophenyl-diphenylphosphane sulfide and 1-

bromo-4’-(diphenylphosphane sulfide)biphenyl is shown in the

Supporting Information. Furthermore, the complete assignment of

the NMR spectra of all reported compounds is given in the Sup-

porting Information. NMR spectra were recorded on a Bruker

Avance DRX 400 and on a Bruker Fourier 300 NMR spectrometer.

The signals for cyclopentadienyl protons often split into pseudo

triplets which are indicated as “pt”. Mass spectra were obtained

with a ZAB-HSQ-VG12–520 (Analytical Manchester) mass spectrom-

eter and a MASPEC II spectrometer. Elemental analyses were deter-

mined with a Heraeus Vario EL analyzer. FTIR spectra were ob-

tained with a Perkin–Elmer FTIR spectrum 2000 spectrometer. GC-

MS analyses were performed with a GC-MS spectrometer GCMS-

QP2010 designed by Shimadzu. The chromatograms were obtained

in their graphical versions using a GCMS solution version 2.53SU1

with an integrated substances databank NIST.

number of catalytic sites per molecule plus their proximity to

each other results in a better performance of the catalyst. It is

furthermore assumed that the spatial proximity of the catalytic

entities facilitates substrate migration and even stabilizes tran-

sition states.^[10]

The corresponding triphenyl phosphane complex [(h⁶-p-cym-

ene)RuCl₂(PPh₃)]^[18]was used as a reference compound and

gave full conversion after 170 min under similar conditions

(Table 6, entry 13). A ferrocene moiety already increases the

catalytic activity of the phosphane ligand by about 90% (5a-

Ru, Table 6, entry 2), and the grafting to the surface of den-

drimers yielded an activity increase of about 240% (11a-G₃-Ru,

entry 11). Furthermore, complexes with a phenylene spacer

(5a-Ru (entry 2), 11a-G₁-Ru (entry 5) and 11a-G₂-Ru (entry 8),

and 11a-G₃-Ru (entry 11)) exhibit the highest catalytic activities

in the redox isomerization of 1-octen-3-ol. The performance of

these complexes (“phenylene spacer family”) is visualized in

Figure 9 showing typical sigmoidal plots of conversion versus

time for the redox isomerization of allylic alcohols.

General procedure for Negishi cross-coupling reactions

n-BuLi (1.1 equiv) was added at ꢀ788C to the bromoferrocene de-

rivative (1.00 equiv) dissolved in THF (15 mL) and the solution was

stirred for 45 min. Anhydrous zinc chloride (1.05 equiv) was added

and the solution was stirred for 2 h at RT. A mixture of tetrakis(tri-

phenylphosphine)palladium(0) (1.0 mol%) and arylbromide

(1.00 equiv), dissolved in THF (5 mL), was added. The solution was

stirred for 12 h under reflux. The reaction mixture was extracted

three times with saturated brine and ethyl acetate. The organic

phase was dried over Na₂SO₄, filtered, and the solvent was re-

moved. The crude oily product was purified by using column chro-

matography on silica.

An induction period is observed after adding the substrate

(approximately 15 min, Figure 9) due to formation of the active

species. Although there is no experimental evidence, it is as-

sumed that chloro ligands at ruthenium are substituted by

a carbonate ligand from Cs₂CO₃.^[4d]This induction period could

be decreased and unified by preheating of catalyst and Cs₂CO₃

at 608C for 5 min.

Conclusion

1-Bromo-1’-(4-methoxyphenyl)ferrocene (2): Compound 2 was

obtained as an orange solid by Negishi cross-coupling of 1,1’-di-

bromoferrocene (1) and 4-bromoanisole. Yield: 3.21 g (59%); R_f

(hexane/CH₂Cl₂4:1)=0.33; M.p. 508C. ¹H NMR (400 MHz, CDCl₃):

d=3.81 (s, 3H), 3.96 (m, 2H), 4.19 (m, 2H), 4.32 (m, 2H), 4.56 (m,

2H), 6.85 (d, 2H, ³J_HH=8.5 Hz), 7.43 ppm (d, 2H, ³J_HH=8.6 Hz);

¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=55.3 (s), 68.5 (s), 68.6 (s), 71.1

(s), 71.7 (s), 78.4 (s), 87.7 (s), 113.9 (s), 127.4 (s), 129.9 (s), 158.3 ppm

A new homogeneous catalytic system for the redox isomeriza-

tion of the allylic alcohol 1-octen-3-ol to 3-octanone has been

developed. The complexes [(h⁶-p-cymene)RuCl₂(L)], with L

being a ferrocenyl-substituted triphenyl phosphane derivative,

showed high catalytic activities. The electronic properties of

the complexes were altered by introducing different spacers

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(s); FTIR (KBr): n˜ =3435 (s), 3106 (w), 3014 (w), 2940 (w), 2842 (w),

1613 (m), 1531 (m), 1460 (m), 1440 (w), 1385 (w), 1353 (w), 1306

(w), 1292 (w), 1280 (w), 1260 (m), 1249 (m), 1179 (m), 1112 (w),

1087 (w), 1033 (m), 889 (w), 872 (w), 832 (m), 798 (w), 607 (w), 532

(w), 491 (w), 473 cm^ꢀ1(w); ESI-MS (+): m/z 370.1 [M]⁺; elemental

analysis calcd (%) for C₁₇H₁₅BrFeO (371.06): C 55.03, H 4.07; found:

C 55.03, H 4.17.

1493 (w), 1458 (m), 1437 (s), 1391 (w), 1305 (w), 1278 (w), 1248 (s),

1179 (m), 1106 (s), 1033 (m), 1002 (w), 892 (w), 820 (s), 772 (w), 751

(w), 694 (s), 647 (m), 615 (w), 540 (m), 520 (m), 437 (w), 413 (w),

406 cm^ꢀ1(w); ESI-MS (+): m/z 660.2 [M]⁺; elemental analysis calcd

(%) for C₄₁H₃₃FeOPS (660.59): C 74.55, H 5.04; found: C 69.73, H

5.13.

1-((4-Phenyl)diphenylphosphino)-1’-(4-hydroxy-phenyl)ferrocene

(5a): Compound 4a (0.40 g, 0.68 mmol) was dissolved in acetoni-

trile/toluene (1:1, 5:5 mL) and added to a Raney nickel (excess) sus-

pension in toluene. The resulting suspension was stirred at 808C

for 72 h (³¹P{¹H} NMR control). Raney nickel was filtered off and

washed with toluene, then the solvent was removed and an

1-(Diphenylphosphino)-1’-(4-methoxyphenyl)ferrocene (3): Com-

pound 3 was obtained as an orange solid by Negishi cross-cou-

pling of 2 and chlorodiphenylphosphane. Yield: 0.34 g (71%). R_f

(hexane/CH₂Cl₂4:1)=0.15; M.p. 1658C; ¹H NMR (400 MHz, CDCl₃):

d=3.79 (s, 3H), 3.93 (m, 2H), 4.14 (m, 2H), 4.19 (m, 2H), 4.46 (m,

3

2H), 6.78 (d, 2H, J_HH=8.6 Hz), 7.27 (d, 2H, J_HH=8.7 Hz), 7.29–7.32

1

orange solid was obtained. Yield: 0.35 g (93%). H NMR (400 MHz,

(m, 6H), 7.33–7.38 ppm (m, 4H). ¹³C{¹H} NMR (100.6 MHz, CDCl₃)

CDCl₃): d=3.79 (s, 3H), 4.16 (m, 2H), 4.22 (m, 2H), 4.38 (m, 2H),

d=55.3 (s), 67.1 (s), 69.9 (s), 72.9 (d, ³J_CP=6.0 Hz), 74.2 (d, J_CP

=

3

2

4.44 (m, 2H), 6.74 (d, 2H, J_HH=8.6 Hz), 7.15 (d, 2H, J_HH=7.9 Hz),

7.21 (d, 2H, ³J_HH=8.7 Hz), 7.27 (m, 2H), 7.30–7.38 ppm (m, 10H);

¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=55.3 (s), 67.6 (s), 67.9 (s), 70.1

1

19.1 Hz), 76.3 (d, J_CP=9.1 Hz), 86.6 (s), 113.9 (s), 127.3 (s), 128.1 (d,

³J_CP=9.1 Hz), 128.4 (s), 130.5 (s), 133.5 (d, J_CP=25.1 Hz), 139.2 (d,

2

¹J_CP=13.1 Hz), 158.1 ppm (s); ³¹P{¹H} NMR (162 MHz, CDCl₃) d=

ꢀ16.8 ppm (s); FTIR (KBr): n˜ =3466 (m), 3068 (w), 3003 (w), 2963

(w), 1611 (w), 1527 (m), 1456 (m), 1435 (m), 1287 (w), 1250 (m),

1182 (m), 1159 (w), 1088 (w), 1035 (m), 829 (m), 750 (m), 741 (m),

695 (m), 539 (w), 502 cm^ꢀ1(m); ESI-MS (+): m/z 476.1 [M]⁺; ele-

mental analysis calcd (%) for C₂₉H₂₅FeOP (476.33): C 73.12, H 5.29;

found: C 71.59, H 5.30.

3

(s), 70.7 (s), 85.0 (s), 86.6 (s), 113.7 (s), 126.1 (d, J_CP=7.4 Hz), 127.0

2

(s), 128.5 (d, ³J_CP=7.0 Hz), 128.7 (s), 130.0 (s), 133.6 (d, J_CP

=

2

1

19.6 Hz), 133.7 (d, J_CP=19.4 Hz), 133.9 (s), 137.4 (d, J_CP=10.7 Hz),

139.3 (s), 158.0 ppm (s); ³¹P{¹H} NMR (162 MHz, CDCl₃): d=

ꢀ6.0 ppm (s); FTIR (KBr): n˜ =3442 (s), 2347 (w), 1631 (m), 1526 (m),

1497 (w), 1459 (w), 1437 (w), 1385 (m), 1248 (m), 1180 (w), 1108

(w), 1032 (w), 827 (m), 697 (w), 535 (w), 463 cm^ꢀ1(w); ESI-MS (+):

m/z 552.2 [M]⁺; elemental analysis calcd (%) for C₃₅H₂₉FeOP

(552.43): C 76.10, H 5.29; found: C75.73, H 5.54.

1-((4-Diphenylphosphane sulfide)phenyl)-1’-(4-methoxyphenyl)-

ferrocene (4a): Compound 4a was obtained as an orange solid by

Negishi cross-coupling of 2 and 4-bromophenyl diphenylphosphane

sulfide. Yield: 0.51 g (45%). R_f(hexane/CH₂Cl₂4:1)=0.15; M.p. 618C.

¹H NMR (400 MHz, CDCl₃): d=3.78 (s, 3H), 4.16 (m, 2H), 4.26 (m,

1-(4-(4’-Diphenylphosphino)1,1’-biphenyl)-1’-(4-methoxyphenyl)-

ferrocene (5b): Compound 4b (0.18 g, 0.27 mmol) were dissolved

in toluene (10 mL) and added to a Raney nickel (excess) suspension

in toluene (5 mL). The suspension was stirred at 808C for 72 h

(³¹P{¹H} NMR control). Raney nickel was filtered off and washed

with toluene, then the solvent was removed and an orange solid

3

2H), 4.39 (m, 2H), 4.47 (m, 2H), 6.73 (d, 2H, J_HH=8.7 Hz), 7.19 (d,

3

4

2H, J_HH=8.5H), 7.33 (dd, 2H, J_HH=8.3, J_HP=2.8 Hz), 7.40–7.48 (m,

3

4H), 7.49–7.55 (m, 4H), 7.74 ppm (dd, 4H, J_HP=13.6, J_HH=7.1 Hz);

¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=55.4 (s), 67.7 (s), 68.3 (s), 70.4

(s), 71.3 (s), 83.9 (s), 87.0 (s), 113.8 (s), 125.8 (d, J_CP=12.8 Hz), 127.0

1

3

was obtained. Yield: 0.12 g (80%). M.p. 1808C; H NMR (400 MHz,

3

1

CDCl₃): d=3.70 (s, 3H), 4.19 (pt, 2H), 4.24 (pt, 2H), 4.42 (pt, 2H),

(s), 128.5 (d, J_CP=12.3 Hz), 129.1 (d, J_CP=87.5 Hz), 129.7 (s), 131.5

(d, ⁴J_CP=2.5 Hz), 132.2 (d, ²J_CP=11.6 Hz), 132.3 (d, ²J_CP=10.8 Hz),

133.1 (d, ¹J_CP=85.5 Hz), 142.9 (s), 158.2 ppm (s); ³¹P{¹H} NMR

(162 MHz, CDCl₃) d=43.0 ppm (s); FTIR (KBr): n˜ =3453 (m), 3095

(w), 3055 (w), 3006 (w), 2952 (w), 2933 (w), 2832 (w), 2346 (w), 1610

(m), 1597 (m), 157 (w), 1553 (w), 1526 (s), 1481 (w), 145 (m), 1437

(s), 1407 (w), 1386 (w), 1329 (w), 1305 (w), 1287 (m), 1277 (m), 1250

(s), 1208 (w), 1179 (m), 1107 (s), 1085 (m), 1076 (m), 1033 (s), 999

(w), 890 (w), 880 (w), 828 (s), 791 (w), 751 (w), 73 (m), 717 (s), 694

(m), 648 (s), 630 (m), 616 (w), 604 (w), 541 (s), 529 (s), 507 (m), 484

(w), 474 (w), 412 cm^ꢀ1(w); ESI-MS (+): m/z 584.2 [M]⁺; elemental

analysis calcd (%) for C₃₅H₂₉FeOPS (584.49): C 71.92, H 5.00; found:

C 72.02, H 4.92.

3

4.51 (pt, 2H), 6.70 (d, 2H, J_HH=8.7 Hz), 7.19 (d, 2H, J_HH=8.7 Hz),

3

7.31 (d, 2H, J_HH=8.3 Hz), 7.36 (m, 10H), 7.39 (m, 2H), 7.41 (m, 2H),

7.60 ppm (d, 2H, ³J_HH=8.3, ⁴J_HP=1.4 Hz); ¹³C{¹H} NMR (100.6 MHz,

CDCl₃): d=55.2 (s), 67.4 (s), 67.7 (s), 70.0 (s), 70.4 (s), 85.4 (s), 86.7

(s), 113.7 (s), 126.3 (s), 126.7 (d, ³J_CP=5.9 Hz), 126.8 (s), 127.0 (s),

3

2

128.6 (d, J_CP=6.9 Hz), 128.8 (s), 129.7 (s), 133.8 (d, J_CP=19.4 Hz),

134.3 (d, ²J_CP=19.7 Hz), 135.7 (d, ¹J_CP=10.6 Hz), 137.3 (d, J_CP

1

=

10.6 Hz), 137.5 (s), 137.6 (s), 141.3 (s), 158.0 ppm (s); ³¹P{¹H} NMR

(162 MHz, CDCl₃): d=ꢀ6.1 ppm (s); FTIR (KBr): n˜ =3438 (m), 2925

(w), 2852 (w), 2212 (w), 1734 (w), 1717 (w), 1698 (w), 1637 (m),

1559 (w), 1541 (w), 1526 (w), 1508 (w), 1490 (w), 1474 (w), 1458

(w), 1435 (w), 1388 (w), 1250 (m), 1179 (w), 1088 (w), 1034 (m), 892

(w), 817 (m), 743 (w), 696 (w), 606 (w), 505 (w), 472 (w), 457 (w),

419 cm^ꢀ1(w); ESI-MS (+): m/z 629.2 [M+H]⁺; elemental analysis

calcd (%) for C₄₁H₃₃FeOP (628.52): C 78.35, H 5.29; found: C 77.05,

H 5.85.

1-(4-(4’-Diphenylphosphane sulfide)biphenyl)-1’-(4-methoxyphe-

nyl)ferrocene (4b): Compound 4b was obtained as an orange

solid by Negishi cross-coupling of 2 and 1-bromo-4’-(diphenylphos-

phino sulfide)biphenyl. Yield: 0.28 g (31%); R_f(hexane/CH₂Cl₂

1

4:1)=0.10; M.p. 1788C; H NMR (400 MHz, CDCl₃): d=3.69 (s, 3H),

1-Bromo-1’-((4-phenoxy)tert-butyldimethylsilyl) ferrocene (6):

Compound 6 was obtained as a dark orange solid by Negishi

cross-coupling of 1,1’-dibromoferrocene and (4-bromophenoxy)(-

tert-butyl)dimethylsilane. Yield: 1.41 g (66%); R_f(hexane/CH₂Cl₂

4:1)=0.50; M.p. 588C; ¹H NMR (400 MHz, CDCl₃): d=0.21 (s, 6H),

0.99 (s, 9H), 3.96 (pt, 2H), 4.19 (pt, 2H), 4.33 (pt, 2H), 4.57 (pt, 2H),

6.79 (d, 2H, ³J_HH=8.6 Hz), 7.36 ppm (d, 2H, ³J_HH=8.6 Hz);

¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=ꢀ4.6 (s), 18.0 (s), 25.5 (s), 68.3

(s), 68.4 (s), 70.9 (s), 71.4 (s), 78.2 (s), 87.4 (s), 119.9 (s), 127.1 (s),

130.2 (s), 154.1 ppm (s); FTIR (KBr): n˜ =3453 (m), 2955 (m), 2931

(m), 2858 (m), 1606 (w), 1523 (s), 1455 (m), 1254 (s), 1101 (m), 1014

(m), 911 (s), 844 (s), 802 (s), 527 (m), 487 cm^ꢀ1(m); EI-MS: m/z 470

4.20 (m, 2H), 4.26 (m, 2H), 4.43 (m, 2H), 4.52 (m, 2H), 6.70 (d, 2H,

3

³J_HH=8.5 Hz), 7.18 (d, 2H, J_HH=8.7 Hz), 7.32 (d, 2H, J_HH=8.3 Hz),

7.41 (d, 2H, ³J_HH=8.4 Hz), 7.45–7.50 (m, 4H), 7.52–7.56 (m, 2H),

7.69 (dd, 2H, ³J_HH=8.4 Hz, ⁴J_HP=2.7 Hz), 7.75–7.82 ppm (m, 6H);

¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=55.1 (s), 67.4 (s), 67.7 (s), 70.0

(s), 70.5 (s), 85.1 (s), 86.8 (s), 113.7 (s), 126.4 (s), 126.7 (d, J_CP

3

=

3

17.1 Hz), 126.9 (s), 127.0 (s), 128.6 (d, J_CP=17.1 Hz), 129.6 (s), 131.6

4

2

(d, J_CP=3.0 Hz), 132.3 (d, J_CP=14.1 Hz), 132.5 (s), 132.8 (d, J_CP

=

14.1 Hz), 133.6 (s), 136.8 (s), 138.4 (s), 144.1 (d, ⁴J_CP=3.0 Hz),

158.0 ppm (s); ³¹P{¹H} NMR (162 MHz, CDCl₃): d=43.0 ppm (s); FTIR

(KBr): n˜ =3453 (s), 3077 (w), 2931 (w), 1609 (m), 1596 (m), 1526 (m),

Chem. Eur. J. 2015, 21, 1 – 16

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ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

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Full Paper

[M]⁺; elemental analysis calcd (%) for C₂₂H₂₇BrFeOSi (471.28): C

56.07, H 5.77; found: C 56.00, H 5.98.

4H), 7.75 ppm (ddd, 4H, ³J_HP=13.3, ³J_HH=8.3 Hz, ⁴J_HH=1.6 Hz);

¹³C{¹H} NMR (75 MHz, CDCl₃): d=ꢀ4.3 (s), 18.3 (s), 25.8 (s), 67.9 (s),

3

68.5 (s), 70.4 (s), 71.4 (s), 83.7 (s), 86.7 (s), 120.1 (s), 125.9 (d, J_CP

=

1-(Diphenylphosphino)-1’-((4-phenoxy)tert-butyldimethylsilyl)-

ferrocene (7): Compound 6 (0.35 g, 0.74 mmol) was dissolved in

THF (8 mL) and stirred at ꢀ788C. nBuLi (0.53 mL, 0.82 mmol, 1.55m

in hexanes) was added and the solution was stirred for 45 min.

Chlorodiphenylphosphane (0.133 mL, 0.74 mmol) was slowly added

through a syringe and the solution was allowed to warm up to

room temperature and stirred for 12 h. The solvent was removed,

the remaining oil was dissolved in CH₂Cl₂and extracted three

times under N₂-atmosphere with degassed saturated brine. The or-

ganic phase was dried with MgSO₄, filtered and the solvent re-

moved. The crude oily product was purified by using inert column

chromatography on degassed silica (hexane/CH₂Cl₂4:1 grad. 1:1)

and an orange solid was obtained. Yield: 0.40 g (94%). R_f(hexane/

3

1

13.0 Hz), 127.0 (s), 128.6 (d, J_CP=12.6 Hz), 129.3 (d, J_CP=87.8 Hz),

4

2

130.7 (s), 131.5 (d, J_CP=2.5 Hz), 132.3 (d, J_CP=10.6 Hz), 133.2 (d,

¹J_CP=85.6 Hz), 143.7 (d, ⁴J_CP=2.5 Hz), 154.2 ppm (s); ³¹P{¹H} NMR

(162 MHz, CDCl₃): d=42.8 ppm (s); FTIR (KBr): n˜ =3432 (s), 2959

(w), 2928 (w), 2855 (w), 2366 (w), 1597 (m), 1524 (m), 1456 (w),

1436 (w), 1407 (w), 1262 (s), 1170 (w), 1102 (s), 1028 (m), 912 (w),

805 (m), 750 (w), 733 (w), 715 (w), 692 (w), 649 (w), 630 (w), 615

(w), 584 (w), 562 (w), 537 (m), 500 (w), 457 (w), 449 (w), 442 (w),

421 (w), 416 cm^ꢀ1(w); ESI-MS (+): m/z 685.2 [M+H]⁺, 707.1 [M+

Na]⁺; elemental analysis calcd (%) for C₄₀H₄₁FeOPSSi (684.72): C

70.16, H 6.04; found: C 69.20, H 6.03.

1

1-(4-(4’-Diphenylphosphane

sulfide)biphenyl)-1’-((4-phenoxy)-

CH₂Cl₂4:1)=0.20; M.p. 1008C; H NMR (400 MHz, CDCl₃): d=0.20

tert-butyldimethylsilyl)ferrocene (9b): Compound 9b was ob-

tained as an orange solid by Negishi cross-coupling of 6 and 1-

bromo-4’-(diphenylphosphino sulfide)biphenyl (5.0 mol% tetrakis-

(triphenylphosphine)palladium(0)). The crude product was purified

by recrystallization from ethyl acetate. The red crystals were isolat-

ed by filtration, washed with diethyl ether, and dried in vacuo.

Yield: 1.95 g (68%). R_f(hexane/CH₂Cl₂4:1)=0.10; M.p. 1708C;

(s, 6H), 0.98 (s, 9H), 3.92 (m, 2H), 4.13 (pt, 2H), 4.17 (pt, 2H), 4.46

3

(pt, 2H), 6.72 (d, 2H, J_HH=8.5 Hz), 7.21 (d, 2H, J_HH=8.5 Hz), 7.29

(m, 6H), 7.35 ppm (m, 4H); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=

ꢀ4.4 (s), 18.2 (s), 25.7 (s), 67.0 (s), 69.8 (s), 72.9 (d, ³J_CP=3.7 Hz),

2

1

74.1 (d, J_CP=14.8 Hz), 76.1 (d, J_CP=6.6 Hz), 86.5 (s), 119.9 (s), 127.1

(s), 128.1 (d, ³J_CP=6.7 Hz), 128.4 (s), 131.0 (s), 133.4 (d, J_CP

=

2

19.1 Hz), 139.1 (d, ¹J_CP=9.5 Hz), 154.0 ppm (s); ³¹P{¹H} NMR

(162 MHz, CDCl₃): d=ꢀ16.9 ppm (s); FTIR (KBr): n˜ =3442 (m), 3051

(w), 2963 (m), 2929 (w), 2855 (w), 1888 (w), 1608 (w), 1525 (m),

1472 (w), 1456 (m), 1433 (m), 1387 (w), 1361 (w), 1262 (s), 1195 (w),

1175 (m), 1162 (m), 1096 (s), 1026 (s), 910 (m), 804 (s), 751 (m), 743

(w), 697 (m), 671 (w), 63 (w), 535 (w), 520 (w), 500 (m), 453 (w), 438

(w), 419 cm^ꢀ1(w); ESI-MS (+): m/z 577.3 [M+H]⁺, 599.3 [M+Na]⁺,

615.2 [M+K]⁺; elemental analysis calcd (%) for C₃₄H₃₇FeOPSi

(576.57): C 70.83, H 6.47; found: C 68.26, H 6.74.

¹H NMR (400 MHz, CDCl₃): d=0.17 (s, 6H), 0.97 (s, 9H), 4.19 (pt,

3

2H), 4.25 (pt, 2H), 4.41 (pt, 2H), 4.49 (pt, 2H), 6.67 (d, 2H, J_HH

=

3

8.5 Hz), 7.15 (d, 2H, J_HH=8.5 Hz), 7.34 (d, 2H, J_HH=8.2 Hz), 7.43 (d,

3

2H, J_HH=8.3 Hz), 7.45–7.50 (m, 4H), 7.51–7.55 (m, 2H), 7.66–7.72

(m, 2H), 7.78 ppm (dd, 6H, ³J_HP=13.5, ³J_HH=7.1 Hz); ¹³C{¹H} NMR

(100.6 MHz, CDCl₃): d=ꢀ4.4 (s), 18.2 (s), 25.7 (s), 67.5 (s), 68.0 (s),

70.2 (s), 70.7 (s), 87.3 (s), 88.1 (s), 119.9 (s), 126.4 (s), 126.7 (s), 126.9

3

(s), 126.8–127.0 (m), 128.6 (d, J_CP=12.3 Hz), 130.5 (m), 131.6 (m),

1

132.3 (d, ²J_CP=10.8 Hz), 132.8 (d, ²J_CP=11.2 Hz), 133.1 (d, J_CP

=

84.9 Hz),137.0 (s), 138.6 (s), 144.2 (s), 154.1 ppm (s); ³¹P{¹H} NMR

(162 MHz, CDCl₃): d=42.8 ppm (s); FTIR (KBr): n˜ =3450 (s), 2959

(m), 2857 (w), 2347 (w), 1686 (w), 1684 (w), 1653 (w), 1609 (m),

1540 (w), 1525 (s), 1455 (m), 1438 (m), 1386 (w), 1262 (s), 1170 (w),

1103 (s), 1029 (m), 913 (w), 820 (s), 749 (w), 717 (m), 695 (m), 669

(w), 647 (w), 615 (w), 560 (w), 540 (w), 525 (w), 507 (w), 489 (w),

472 (w), 457 (w), 428 (w), 420 (w), 411 cm^ꢀ1(w); EI-MS: m/z 760

[M]⁺; elemental analysis calcd (%) for C₄₆H₄₅FeOPSSi (760.83): C

72.62, H 5.96; found: C 72.63, H 5.80.

1-(Diphenylphosphino)-1’-((4-hydroxyphenyl)ferrocene (8): Com-

pound 7 (117 mg, 0.20 mmol) and TBAF·3H₂O (126 mg, 0.4 mmol)

were dissolved in THF (5 mL) and the solution was stirred at room

temperature for 3 h. The solvent was removed, the remaining oil

was dissolved in CH₂Cl₂and extracted three times with degassed

saturated brine. The organic layer was dried with MgSO₄, filtered

and the solvent removed. The crude oily product was purified by

using inert column chromatography on degassed silica (hexane/

CH₂Cl₂2:1 grad. CH₂Cl₂) and an orange oily product was obtained.

Yield: 71 mg (76%). R_f(CH₂Cl₂)=0.30; ¹H NMR (400 MHz, CDCl₃):

d=3.94 (s, 2H), 4.14 (s, 2H), 4.19 (s, 2H), 4.46 (s, 2H), 5.37 (brs,

1-((4-Phenyl)diphenylphosphane sulfide)-1’-(4-hydroxyphenyl)-

ferrocene (10a): Compound 9a (1.14 g, 1.65 mmol) was dissolved

in THF (12 mL). TBAF·3H₂O (0.95 g, 3.30 mmol) was added and the

solution was stirred at room temperature for 3 h. The mixture was

extracted with ethyl acetate/NH₄Cl. The organic phase was dried

over Na₂SO₄, filtered and the solvent removed. The crude oily prod-

uct was purified by using column chromatography on silica

(hexane/CH₂Cl₂3:1 grad. CH₂Cl₂) and a luminescent orange solid

was obtained. Yield: 0.91 g (97%); R_f(CH₂Cl₂)=0.20; M.p. 1768C;

¹H NMR (300 MHz, CDCl₃): d=4.22 (s, 2H), 4.34 (s, 2H), 4.54 (s, 2H),

4.59 (s, 2H), 6.34 (m, 1H), 6.53 (d, 2H, ³J_HH=8.5 Hz), 6.81 (d, 2H,

³J_HH=8.4 Hz), 7.00 (dd, 2H, ³J_HH=7.7, ⁴J_HP=2.8 Hz), 7.13 (dd, 2H,

³J_HP=13.0, ³J_HH=8.2 Hz), 7.40–7.58 (m, 6H), 7.79 ppm (dd, 4H,

3

1H), 6.73 (d, 2H, J_HH=8.5 Hz), 7.20 (d, 2H, J_HH=8.4 Hz), 7.31 (m,

6H), 7.36 ppm (m, 4H); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=67.1 (s),

2

69.8 (s), 72.9 (m), 74.2 (d, J_CP=14.4 Hz), 75.6 (s), 86.6 (s), 115.3 (s),

3

2

127.4 (s), 128.1 (d, J_PC=6.6 Hz), 128.6 (s), 130.3 (s), 133.4 (d, J_CP

=

18.9 Hz), 138.8 (d, ¹J_CP=9.6 Hz), 154.2 ppm (s); ³¹P{¹H} NMR

(162 MHz, CDCl₃) d=ꢀ16.5 ppm (s); FTIR (KBr): n˜ =3426 (s), 3068

(m), 2927 (m), 2868 (m), 1611 (m), 1527 (s), 1478 (m), 1433 (m),

1385 (w), 1325 (w), 1308 (w), 1262 (s), 1223 (m), 1194 (m), 1161 (m),

1100 (m), 1069 (m), 1026 (s), 885 (m), 829 (s), 742 (s), 697 (s), 660

(w), 631 (w), 608 (w), 571 (w), 526 (m), 500 (m), 455 cm^ꢀ1(m);

HRMS (ESI): m/z calcd for C₂₈H₂₄FeOP: 463.09087 [M]⁺; found:

463.09055.

3

1-((4-Phenyl)diphenylphosphane sulfide)-1’-((4-phenoxy)tert-bu-

tyldimethylsilyl)ferrocene (9a): Compound 9a was obtained as an

orange solid by Negishi cross-coupling of 6 and 4-bromophenyl-di-

phenylphosphane sulfide (5.0 mol% tetrakis(triphenylphosphine)-

palladium(0)). Yield: 1.86 g (92%). R_f(hexane/CH₂Cl₂4:1)=0.10;

³J_HP=13.3, J_HH=8.1 Hz); ¹³C{¹H} NMR (75 MHz, CDCl₃): d=66.4 (s),

3

67.2 (s), 69.3 (s), 70.1 (s), 84.4 (s), 87.9 (s), 116.3 (s), 125.7 (d, J_CP

=

3

1

13.4 Hz), 126.4 (s), 127.1 (s), 128.5 (d, J_CP=12.6 Hz), 128.7 (d, J_CP

88.6 Hz), 131.7 (d, ⁴J_CP=2.6 Hz), 132.1 (d, ²J_CP=11.3 Hz), 132.1 (d,

¹J_CP=88.1 Hz), 132.5 (d, ²J_CP=10.7 Hz), 141.0 (s), 154.3 ppm (s);

³¹P{¹H} NMR (162 MHz, CDCl₃): d=43.3 ppm (s); FTIR (KBr): n˜ =3420

(s), 2929 (s), 1612 (m), 1384 (m), 1262 (s), 1100 (s), 805 (s), 669 cm^ꢀ1

(w); EI-MS: m/z 570 [M]⁺; elemental analysis calcd (%) for

C₃₄H₂₇FeOPS (570.47): C 71.59, H 4.77; found: C 71.08, H 4.95.

1

M.p. 708C; H NMR (300 MHz, CDCl₃): d=0.19 (s, 6H), 0.99 (s, 9H),

4.15 (m, 2H), 4.25 (m, 2H), 4.36 (m, 2H), 4.44 (m, 2H), 6.71 (d, 2H,

³J_HH=8.5 Hz), 7.18 (d, 2H, ³J_HH=8.6 Hz), 7.37 (dd, 2H, ³J_HH=8.2,

⁴J_HP=2.6 Hz), 7.47 (dd, 4H, ³J_HH=7.8, ⁴J_HP=2.9 Hz), 7.50–7.62 (m,

&

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1-(4-(4’-Diphenylphosphane sulfide)biphenyl)-1’-(4-hydroxyphe-

nyl)ferrocene (10b): Compound 9b (0.78 g, 1.03 mmol) was dis-

solved in THF (10 mL). Then, TBAF·3H₂O (0.39 g, 1.23 mmol) was

added and the solution was stirred at room temperature for 8 h.

The mixture was extracted three times in diethyl ether/NH₄Cl and

washed with water. The organic phase was dried over Na₂SO₄, fil-

tered and the solvent removed. The crude oily product was puri-

fied by using column chromatography on silica (hexane/CH₂Cl₂1:1

grad. CH₂Cl₂) and an orange solid was obtained. Yield: 0.61 g

154.1 ppm (s); ³¹P{¹H} NMR (162 MHz, CDCl₃): d=ꢀ5.9 ppm (s);

FTIR (KBr): n˜ =3446 (s), 3066 (w), 2965 (w), 2346 (w), 1611 (m), 1527

(s), 1456 (m), 1434 (m), 1386 (m), 1262 (m), 1218 (w), 1173 (w),

1087 (m), 1029 (m), 1003 (w), 891 (w), 818 (s), 747 (m), 697 (m), 518

(w), 497 (w), 419 cm^ꢀ1(w); ESI-MS (+): m/z 614.2 [M]⁺; elemental

analysis calcd (%) for C₄₀H₃₁FeOP (614.51): C 78.18, H 5.08; found: C

76.40, H 5.14.

General procedure for the synthesis of the dendritic ferrocenyl

phosphanes: A solution of ferrocenyl phosphane (14 equiv for G₁,

28 equiv for G₂, 54 equiv for G₃) in THF (10 mL) was added to a so-

lution of G₁, G₂, or G₃and Cs₂CO₃(29 equiv for G₁, 59 equiv for G₂,

108 equiv for G₃) in degassed THF (7 mL). The mixture was stirred

for 12 h at room temperature, then filtered under argon and the

filtrate was concentrated and precipitated into a mixture of n-pen-

tane/ethyl ether (1:1, 30:30 mL). The resulting powder was washed

twice with n-pentane/ethyl ether (1:1, 30:30 mL).

1

(91%). R_f(CH₂Cl₂)=0.10. M.p. 1608C; H NMR (400 MHz, CDCl₃): d=

4.19 (pt, 2H), 4.26 (pt, 2H), 4.41 (pt, 2H), 4.51 (pt, 2H), 4.68 (s, 1H),

6.62 (d, 2H, ³J_HH=8.5 Hz), 7.12 (d, 2H, ³J_HH=8.5 Hz), 7.31 (d, 2H,

³J_HH=8.3 Hz), 7.40 (d, 2H, ³J_HH=8.4 Hz), 7.44–7.49 (m, 4H), 7.51–

4

7.56 (m, 2H), 7.69 (dd, 2H, ³J_HH=8.3, J_HP=2.8 Hz), 7.78 ppm (dd,

6H, ³J_HP=13.3, ³J_HH=7.6 Hz); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=

67.3 (s), 67.7 (s), 70.0 (s), 70.5 (s), 85.1 (s), 86.7 (s), 115.2 (s), 126.4

3

(s), 126.7 (d, ³J_CP=12.7 Hz), 127.0 (s), 127.2 (s), 128.6 (d, J_CP

=

Compound 8-G₁: Compound 8 (0.167m, 0.551 mmol, 14 equiv)

was grafted to G₁(0.039 mmol) according to the general proce-

dure. Yield: 211 mg (78%); yellow-orange powder. ¹H NMR

(400 MHz, CDCl₃): d=3.23 (d, 18H, ³J_HP=10.1 Hz), 3.92–3.87 (m,

24H), 4.13–4.11 (m, 24H), 4.15–4.13 (m, 24H), 4.44–4.39 (m, 24H),

4

12.7 Hz), 130.2 (d, ¹J_CP=83.2 Hz), 131.5 (s, i-C), 131.6 (d, J_CP

2.5 Hz), 132.3 (d,²J_CP=10.7 Hz), 132.8 (d, ²J_CP=11.1 Hz), 133.0 (d,

¹J_CP=85.3 Hz), 136.8 (s), 138.4 (s), 144.1 (s), 153.9 ppm (s);

³¹P{¹H} NMR (162 MHz, CDCl₃): d=43.0 ppm (s); FTIR (KBr): n˜ =3446

(s), 2966 (w), 2368 (w), 2344 (w), 1774 (w), 1752 (w), 1735 (w), 1719

(w), 1701 (w), 1685 (m), 1654 (m), 1652 (m), 1637 (m), 1618 (m),

1560 (w), 1558 (w), 1541 (w), 1539 (w), 1527 (w), 1508 (w), 1506

(w), 1458 (w), 1438 (w), 1420 (w), 1385 (w), 1262 (m), 1103 (m),

1028 (m), 819 (m), 748 (w), 715 (w), 694 (w), 668 (w), 646 (w), 615

(w), 540 (w), 503 (w), 457 (w), 431 (w), 426 (w), 419 cm^ꢀ1(m); ESI-

MS (+): m/z 646.2 [M]⁺; elemental analysis calcd (%) for

C₄₀H₃₁FeOPS (646.57): C 74.31, H 4.83; found: C 73.47, H 5.32.

3

7.0 (d, 12H, J_HH=8.6 Hz), 7.05 (d, 24H, J_HH=7.6 Hz), 7.20 (d, 24H,

³J_HH=8.7 Hz), 7.28–7.24 (m, 72H), 7.36–7.30 (m, 48H), 7.5 (d, 12H,

⁴J_HP=1.4 Hz), 7.60 ppm (d, 12H, ³J_HH=8.6 Hz); ¹³C{¹H} NMR

3

(100.6 MHz, CDCl₃): d=33.0 (dd, ²J_CP=11.9 Hz), 67.5 (d, J_CP

=

4.2 Hz), 70.3 (s), 73.0 (d, ³J_CP=3.7 Hz), 74.3 (d, ²J_CP=14.6 Hz), 76.5

1

3

(d, J_CP=7.1 Hz), 85.3 (s), 121.2 (d, J_CP=4.6 Hz), 121.4 (brs), 127.2

(s), 128.2 (d, ³J_CP=6.9 Hz), 128.3 (s), 128.5 (s), 132.2 (s), 133.4 (d,

²J_CP=19.4 Hz), 135.8 (s), 138.4 (d, ³J_CP=13.8 Hz), 139.0 (d, J_CP

=

1

9.8 Hz), 148.8 (d, ²J_CP=7.3 Hz), 151.2 ppm (d, ²J_CP=3.4 Hz);

³¹P{¹H} NMR (162 MHz, CDCl₃): d=ꢀ17.1 (s), 8.4 (s), 62.3 ppm (s).

1-((4-Phenyl)diphenylphosphino)-1’-(4-hydroxyphenyl)ferrocene

(11a): Compound 10a (77 mg, (0.14 mmol) was dissolved in aceto-

nitrile (25 mL) and added to a Raney nickel (excess) suspension in

acetonitrile (5 mL). The reaction mixture was stirred at room tem-

perature for 12 h (³¹P{¹H} NMR control). After filtration and washing

with acetonitrile, the solvent was removed and an orange solid

was obtained. Yield: 65 mg (90%). R_f(CH₂Cl₂)=0.32. M.p. 1288C;

¹H NMR (300 MHz, CDCl₃): d=4.16 (s, 2H), 4.22 (s, 2H), 4.38 (s, 2H),

Compound 8-G₂: Compound 8 (0.551 mmol, 28 equiv) was grafted

to G₂(0.019 mmol) according to the general procedure. Yield:

228 mg (80%), yellow-orange powder. ¹H NMR (400 MHz, CDCl₃):

d=3.12 (d, 18H, ³J_HP=10.0 Hz), 3.21 (d, 36H, ³J_HP=10.1 Hz), 3.87

3

(brs, 48H), 4.18–4.05 (m, 96H), 4.41 (m, 48H), 6.88 (d, 12H, J_HH

=

3

8.6 Hz), 7.04 (d, 48H, J_HH=8.3 Hz), 7.27–7.12 (m, 168H); 7.37–7.29

(m, 144H), 7.49 (s, 12H), 7.64–7.52 ppm (m, 42H); ¹³C{¹H} NMR

(100.6 MHz, CDCl₃): d=32.8–33.2 (m), 67.5 (d, ²J_CP=10.8 Hz), 70.3

3

4.45 (s, 2H), 4.75 (brs, 1H), 6.59 (d, 2H, J_HH=8.4 Hz), 7.05–7.15 (m,

4H), 7.21 (d, 2H, ³J_HH=8.4 Hz), 7.36 ppm (m, 10H); ¹³C{¹H} NMR

(75 MHz, CDCl₃): d=67.4 (s), 67.8 (s), 70.0 (s), 70.5 (s), 85.1 (s), 86.6

2

1

(s), 73.0 (s), 74.3 (dd, J_CP=14.7, 5.4 Hz), 76.5 (d, J_CP=7.0 Hz), 85.3

3

(s), 115.3 (s), 126.0 (d, J_CP=7.2 Hz), 127.1 (s), 128.5 (d, J_CP=6.8 Hz),

(s), 121.3 (d, J_CP=4.3 Hz), 121.5 (brs), 121.8 (brs), 127.2 (s), 128.2

2

3

128.7 (s), 133.7 (d, J_CP=19.8 Hz), 129.9 (s), 133.8 (d, J_CP=19.4 Hz),

137.4 (d, ¹J_CP=10.7 Hz), 139.0 (s), 153.9 ppm (s); ³¹P{¹H} NMR

(162 MHz, CDCl₃): d=ꢀ6.0 ppm (s); FTIR (KBr): n˜ =3435 (s), 2963

(w), 2924 (w), 2360 (w), 2342 (w), 1637 (m), 1560 (w), 1541 (w),

1528 (w), 1508 (w), 1458 (w), 1262 (m), 1095 (m), 1028 (m), 805

(m), 698 (w), 669 (w), 526 (w), 420 cm^ꢀ1(w); ESI-MS: m/z 539.1

[M+H]⁺; elemental analysis calcd (%) for C₃₄H₂₇FeOP (538.40): C

75.85, H 5.05; found: C 75.61, H 5.05.

(d, J_CP=6.8 Hz), 128.3 (s), 128.4 (brs), 128.5 (s), 132.1 (s), 132.4 (s),

2

3

133.4 (d, J_CP=19.4 Hz), 135.8 (s), 138.4 (d, J_CP=13.2 Hz), 139.0 (d,

³J_CP=9.7 Hz), 148.8 (d, ³J_CP=7.2 Hz), 151.2 ppm (d, ²J_CP=7 Hz);

³¹P{¹H} NMR (162 MHz, CDCl₃) d=ꢀ17.1 (s), 8.5 (s), 62.5 ppm (brs).

Compound 8-G₃: Compound 8 (0.551 mmol, 56 equiv) was grafted

to G₃(0.009 mmol) according to the general procedure. Yield:

219 mg (79%), yellow-orange powder. ¹H NMR (400 MHz, CDCl₃):

d=3.08–3.27 (m, 126H), 3.86 (brs, 96H), 4.10 (m, 192H), 4.40 (m,

96H), 7.11–6.99 (m, 108H), 7.23 (brs, 360H), 7.3 (brs, 288H), 7.73–

7.43 ppm (m, 126H); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=33.0 (m),

1-(4-(4’-Diphenylphosphino)biphenyl)-1’-(4-hydroxyphenyl)ferro-

cene (11b): Compound 10b (0.55 g, 0.85 mmol) was dissolved in

toluene (10 mL) and added to a Raney nickel (excess) suspension

in toluene (10 mL). The reaction mixture was stirred at 858C for

12 h (³¹P{¹H} NMR control). After filtration and washing with tolu-

ene, the solvent was removed and a red-orange solid was ob-

3

2

67.5 (d, J_CP=4.6 Hz), 70.3 (s), 73.0 (s), 74.3 (d, J_CP=14 Hz), 76.5 (d,

¹J_CP=7.2 Hz), 85.3 (s), 121.3 (d, J_CP=4 Hz), 121.3 (brs), 121.9 (brs),

3

127.1 (s), 128.2 (d, J_CP=6.8 Hz), 128.3 (s); 128.4 (s), 128.5 (s), 132.4

(brs), 133.4 (d, J_CP=19.4 Hz), 135.8 (brs), 138.5 (d, ³J_CP=12.5 Hz),

3

139.0 (d, ³J_CP=9.7 Hz), 148.8 (d, ³J_CP=7.1 Hz), 151.3 ppm (s);

³¹P{¹H} NMR (162 MHz, CDCl₃): d=ꢀ17.1 (s), 8.5 (s), 62.3 ppm (s).

1

tained. Yield: 0.44 g (84%). M.p. 1658C; H NMR (400 MHz, CDCl₃):

d=4.19 (m, 2H), 4.23 (m, 2H), 4.39 (m, 2H), 4.48 (m, 2H), 6.68 (d,

2H, ³J_HH=8.4 Hz), 7.14 (d, 2H, ³J_HH=8.6 Hz), 7.18–7.27 (m, 2H),

Compound 11a-G₁: Compound 11 a (618 mg, 1.14 mmol, 14 equiv)

was grafted to G₁(0.082 mmol) according to the general proce-

3

7.31–7.37 (m, 10H), 7.38–7.43 (m, 4H), 7.60 ppm (d, 2H, J_HH

=

7.6 Hz); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=67.3 (s), 67.7 (s), 69.9

(s), 70.4 (s), 85.3 (s), 86.8 (s), 115.3 (s), 126.3 (s), 126.8 (m), 127.1 (s),

128.6 (m), 128.8 (m), 129.6 (s), 132.3 (m), 133.8 (d, ²J_CP=19.0 Hz),

134.3 (d, ²J_CP=19.7 Hz), 135.7 (m), 137.4 (s), 137.8 (s), 141.0 (s),

dure. Yield: 639 mg (99%), red-orange powder. H NMR (400 MHz,

CDCl₃): d=3.22 (d, ³J_HP=10.2 Hz), 4.08 (brs, 48H), 4.29–4.34 (m,

1

24H), 4.35–4.42 (m, 24H), 6.97–7.07 (m, 36H), 7.10–7.25 (m, 72H),

3

7.29–7.36 (m, 120H), 7.54 (s, 6H), 7.60 ppm (d, 12H, J_HH=8.7 Hz);

Chem. Eur. J. 2015, 21, 1 – 16

www.chemeurj.org

11

ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

&

These are not the final page numbers! ÞÞ

Full Paper

2

¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=33.1 (d, J_CP=11.8 Hz), 67.8 (s),

6.9 Hz), 128.7 (s), 128.8 (s), 132.1 (s), 132.4 (s), 133.7 (dd, J_CP=19.6,

4

3

68.0 (s), 70.9 (d, J_CP=4.8 Hz), 71.1 (d, J_CP=5.0 Hz), 85.0 (s), 85.1 (s),

7.9 Hz), 133.7 (d, ³J_CP=11.4 Hz), 134.3 (d, ³J_CP=19.6 Hz), 135.4 (s),

135.7 (d, ¹J_CP=10.9 Hz), 137.2 (d, ³J_CP=11.1 Hz), 137.6 (d, J_CP

18.6 Hz), 138.3–138.6 (m), 141.1 (s), 148.7 (d, ³J_CP=7.2 Hz),

151.2 ppm (d, ²J_CP=6.6 Hz); ³¹P {¹H} NMR (162 MHz, CDCl₃): d=

ꢀ6.2 (s), 8.5 (s), 62.3 (s), 62.5 ppm (s).

Compound 11b-G₃: Compound 11 b (230 mg, 0.37 mmol,

56 equiv) was grafted to G₃(0.0071 mmol) according to the gener-

al procedure. Yield: 213 mg (78%), red-orange powder. ¹H NMR

(400 MHz, CDCl₃): d=3.12 (brs, 126H), 4.04 (brs, 192H), 4.29 (brs,

96H), 4.36 (brs, 96H), 6.96 (brs, 108H), 7.10 (s, 168H), 7.16–7.7.47

(m, 48H), 7.29–7.44 (m, 768H), 7.53 (brs, 138H), 7.64 ppm (brs,

86H); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=32.7–33.2 (m), 67.8 (brs),

70.7 (brs), 85.1 (s), 85.3 (s), 121.2 (brs), 121.8 (brs), 126.2 (brs),

126.8 (brs), 128.2 (brs), 128.5 (s), 128.6 (s), 128.7 (s), 132.1 (s), 132.4

(s), 133.7 (d, J_CP=19.2 Hz), 134.2 (d, J_CP=19.6 Hz), 135.5 (s), 135.7

(d, ¹J_CP=10.9 Hz), 137.2 (d, ³J_CP=11.1 Hz), 137.6 (d, ¹J_CP=18.6 Hz),

138.1–138.5 (m), 141.1 (s), 141.2 (s), 148.7 (brs), 151.2 ppm (brs);

³¹P{¹H} NMR (162 MHz, CDCl₃): d=ꢀ6.2 (s), 8.9 (s), 62.3 ppm (brs).

3

1

121.2 (d, J_CP=4.5 Hz), 121.4 (brs), 126.0 (d, J_CP=7.2 Hz), 126.9 (s),

=

3

2

128.3 (s), 128.5 (d, J_CP=6.9 Hz), 128.7 (s), 132.3 (s), 133.7 (d, J_CP

=

3

1

19.4 Hz), 133.7 (d, J_CP=19.0 Hz), 134.1 (d, J_CP=10.1 Hz), 135.6 (d,

⁴J_CP=1.8 Hz), 137.4 (d, J_CP=11.0 Hz), 138.4 (d, J_CP=14.1 Hz), 139.1

1

3

(s), 148.8 (d, J_CP=7.4 Hz), 151.2 ppm (d, J_CP=4.7 Hz); ³¹P{¹H} NMR

2

(162 MHz, CDCl₃): d=ꢀ6.2 (s), 8.4 (s), 62.5 ppm (s).

Compound 11a-G₂: Compound 11 a (475 mg, 0.88 mmol, 28 equiv)

was grafted to G₂(0.031 mmol) according to the general proce-

dure. Yield: 391 mg (76%), red-orange powder. H NMR (400 MHz,

CDCl₃): d=3.12 (d, 18H, J_HP=10.0 Hz), 3.19 (d, 36H, J_HP=10.3 Hz),

1

3

4.07 (brs, 96H), 4.30 (s, 48H), 4.36 (s, 48H), 6.87 (d, 12H, J_HH

=

8.4 Hz), 7.02 (d, 48H, ³J_HH=8.1 Hz), 7.09–7.23 (m, 168H), 7.29 (s,

240H), 7.46 (s, 12H), 7.51–7.61 ppm (m, 42H). ¹³C{¹H} NMR

(100.6 MHz, CDCl₃): d=32.2–33.8 (m), 67.9 (s), 68.1 (s), 70.9 (d,

2

1

⁴J_CP=6.7 Hz), 71.0 (d, J_CP=6.0 Hz), 85.0 (s), 85.1 (s), 121.3 (d, J_CP

=

3

4.3 Hz), 121.7 (d, ³J_CP=3.8 Hz), 126.0 (d, ³J_CP=7.1 Hz), 126.9 (s),

128.3 (brs), 128.5 (d, ³J_CP=6.8 Hz), 128.7 (s), 132.1 (s), 132.4 (s),

133.7 (dd, ²J_CP=19.6, 7.9 Hz), 133.7 (d, ³J_CP=11.4 Hz), 134.1 (d,

¹J_CP=10.3 Hz), 135.5 (s), 137.4 (d, ¹J_CP=11.1 Hz), 138.4 (d, J_CP

=

3

13.9 Hz), 139.1 (s), 148.8 (d, ³J_CP=7.2 Hz), 151.2 ppm (d, J_CP

2

General procedure for the monomeric ruthenium complexes

6.6 Hz); ³¹P{¹H} NMR (162 MHz, CDCl₃): d=ꢀ6.2 (s), 8.5 (s), 62.4 (s),

The monomeric ferrocenyl phosphane was dissolved in CH₂Cl₂

62.7 ppm (s).

(3 mL)

and

di-m-chlorobis[(p-cymene)chlororuthenium(II)]

Compound 11a-G₃: Compound 11 a (228 mg, 0.42 mmol, 56 equiv)

was grafted to G₃(0.0075 mmol) according to the general proce-

dure. Yield: 177 mg (68%), red-orange powder. H NMR (400 MHz,

(0.5 equiv) was dissolved in CH₂Cl₂(2 mL). The solutions were com-

bined and stirred at room temperature until the ³¹P{¹H} NMR indi-

cated full conversion (0.5–1 h). After silica filtration (CH₂Cl₂/ethyl

acetate 8:1), the product was dissolved in CH₂Cl₂(2–3 mL) and

then precipitated in 150 mL of hexane at 08C. After filtration an

orange solid was obtained.

1

CDCl₃): d=3.12–3.19 (m, 126H), 4.04 (brs, 192H), 4.28 (s, 96H),

3

4.33 (s, 96H), 7.01 (d, 60H, J_HH=7.6 Hz), 7.12 (m, 360H), 7.26 (m,

480H), 7.45 (brs, 42H), 7.59 ppm (m, 84H); ¹³C{¹H} NMR

(100.6 MHz, CDCl₃): d=32.9–33.1 (m), 67.9 (s), 68.1 (s), 70.8 (d,

1-(Diphenylphosphino)[(p-cymene)dichlororuthenium(II)]-1’-(4-

3

⁴J_CP=6.7 Hz), 71.0 (d, J_CP=6.0 Hz), 85.0 (s), 85.1 (s), 121.3 (d, J_CP

=

methoxyphenyl)ferrocene (3-Ru): Compound

3

(103.1 mg,

3 Hz), 121.8 (brs), 126.0 (d, ³J_CP=7.1 Hz), 126.9 (s), 128.3 (brs),

0.22 mmol) was treated with di-m-chlorobis[(p-cymene)chlororuthe-

nium(II)] (66.3 mg, 0.11 mmol) according to the general procedure.

Yield: 162.4 mg (96%), orange powder. R_f(CH₂Cl₂/ethyl acetate

3

2

128.5 (d, J_CP=6.7 Hz), 128.7 (s), 132.1 (s), 132.4 (s), 133.6 (d, J_CP

=

3

1

19.6 Hz), 133.7 (d, J_CP=19.8 Hz), 134.1 (d, J_CP=10.1 Hz), 135.5 (s),

137.4 (d, ¹J_CP=11 Hz), 138.4 (brs), 139.1 (s), 148.8 (d, ³J_CP=7 Hz),

151.2 ppm (brs); ³¹P{¹H} NMR (162 MHz, CDCl₃): d=ꢀ6.3 (s), 8.9 (s),

62.3 (s), 62.5 ppm (s).

1

8:1)=0.70; M.p. 1508C; H NMR (400 MHz, CDCl₃): d=0.96 (d, 6H,

³J_HH=7.0 Hz), 1.78 (s, 3H), 2.55 (sept, 1H, ³J_HH=6.9 Hz), 3.76 (pt,

3

2H), 3.80 (s, 3H), 4.11 (m, 2H), 4.19 (pt, 2H), 4.43 (dd, 2H, J_HH

=

4

3

Compound 11b-G₁: Compound 11 b (330 mg, 0.53 mmol,

14 equiv) was grafted to G₁(0.038 mmol) according to the general

procedure. Yield: 227 mg (68%), red-orange powder. ¹H NMR

(400 MHz, CDCl₃): d=3.14 (d, 18H, ³J_HP=10 Hz), 4.10 (brs, 48H),

4.31 (d, 24H, ³J_HH=15.6 Hz), 4.40 (brs, 24H), 6.93–7.03 (m, 36H),

7.10 (d, 24H, ³J_HH=8.4 Hz), 7.25 (d, 24H, ³J_HH=8.4 Hz), 7.29–7.44

(m, 156H), 7.52 (d, 12H, ³J_HH=11.7 Hz), 7.55–7.62 ppm (m, 30H);

¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=33.1 (d, ²J_CP=11.7 Hz), 67.7

3.5 Hz, J_HH=1.6 Hz), 5.08–5.12 (m, 2H), 6.79 (d, 2H, J_HH=8.8 Hz),

7.23 (d, 2H, ³J_HH=8.8 Hz), 7.37–7.47 (m, 6H), 7.86–7.91 ppm (m,

4H); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=17.1 (s), 21.8 (s), 30.0 (s),

55.3 (s), 67.2 (s), 72.1 (s), 73.2 (d, ³J_CP=7.9 Hz), 75.6 (d, J_PC

2

=

10.5 Hz), 77.3 (m), 85.9 (d), 86.6 (s), 90.1 (d), 95.1 (s), 109.5 (s), 113.8

2

4

(s), 127.2 (s), 127.5 (d, J_CP=9.7 Hz), 130.1 (d, J_CP=2.4 Hz), 130.2 (s),

134.1 (d, ³J_CP=9.7 Hz), 136.7 (s), 154.2 ppm (s); ³¹P{¹H} NMR

(162 MHz, CDCl₃): d=18.8 ppm (s); FTIR (KBr): n˜ =3432 (m), 2963

(w), 2930 (w), 1631 (w), 1558 (w), 1542 (w), 1527 (w), 1459 (w),

1439 (w), 1249 (w), 1161 (w), 1096 (w), 1031 (w), 829 (w), 804 (w),

746 (w), 699 cm^ꢀ1(w); HRMS (ESI): m/z calcd for C₃₉H₃₉ClFeOPRu:

747.08229 [MꢀCl]⁺; found: 747.08227; elemental analysis calcd (%)

for C₃₉H₃₉Cl₂FeOPRu (782.53): C 59.86, H 5.02; found: C 61.00, H

4.97.

3

(brs), 70.8 (s), 71.8 (s), 85.1 (s), 85.3 (s), 121.2 (d, J_CP=4.1 Hz), 121.5

(brs), 126.3 (s), 126.8 (s), 126.8 (s), 126.8 (s), 128.3 (s), 128.5 (d,

2

³J_CP=6.9 Hz), 128.7 (s), 132.4 (s), 133.7 (d, J_CP=19.5 Hz), 134.3 (d,

1

³J_CP=19.6 Hz), 135.4 (s), 135.7 (d, ¹J_CP=10.8 Hz), 137.2 (d, J_CP

=

3

10.9 Hz), 137.5 (s), 137.7 (s), 138.2 (d, J_CP=14.1 Hz), 141.1 (s), 148.7

2

(d, J_CP=7.2 Hz), 151.2 ppm (brs); ³¹P{¹H} NMR (162 MHz, CDCl₃) d=

ꢀ6.1 (s), 8.6 (s), 62.4 ppm (s).

1-((4-Phenyl)diphenylphosphino)[(p-cymene)dichlororutheniu-

m(II)]-1’-(4-methoxyphenyl)ferrocene (5a-Ru): Compound 5a

(50.0 mg, 0.09 mmol) was treated with di-m-chlorobis[(p-cyme-

ne)chloro-ruthenium(II)] (27.7 mg, 0.05 mmol) according to the

general procedure. Yield: 78.0 mg (97%). R_f(CH₂Cl₂/ethyl acetate

Compound 11b-G₂: Compound 11 b (315 mg, 0.51 mmol,

28 equiv) was grafted to G₂(0.018 mmol) according to the general

procedure. Yield: 299 mg (90%), red-orange powder. ¹H NMR

(400 MHz, CDCl₃): d=3.08 (d, 18H, ³J_HP=9.6 Hz), 3.13 (d, 36H,

³J_HP=10 Hz), 4.06 (brs, 96H), 4.31 (s, 48H), 4.38 (s, 48H), 6.87 (brs,

8:1)=0.60; M.p. 1328C; H NMR (400 MHz, CDCl₃): d=1.14 (d, 6H,

1

3

12H), 6.98 (d, 48H, J_HH=8.0 Hz), 7.12 (s, 72H), 7.23 (dd, 48H, J_HH

=

³J_HH=6.9 Hz), 1.91 (s, 3H), 2.90 (sept, 1H, J_HH=7.0 Hz), 3.81 (s, 3H),

7.8, 3.6 Hz), 7.29–7.44 (m, 336H), 7.48–7.60 ppm (m, 102H);

4.17 (pt, 2H), 4.25 (pt, 2H), 4.38 (pt, 2H), 4.46 (pt, 2H), 5.02 (d, 2H,

3

¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=32.8–33.2 (m), 67.7 (s), 67.7 (s),

³J_HH=5.8 Hz), 5.24 (d, 2H, J_HH=6.3 Hz), 6.78 (d, 2H, J_HH=8.4 Hz),

3

70.8 (brs), 85.1 (s), 85.3 (s), 121.3 (d, J_CP=3.6 Hz), 121.4 (brs), 121.7

7.23 (d, 2H, ³J_HH=8.5 Hz), 7.32 (dd, 2H, ³J_HH=8.2, ⁴J_HP=2.2 Hz),

3

(brs), 126.3 (s), 126.8 (s), 126.8 (s), 128.3 (brs), 128.5 (d, J_CP

=

7.37–7.45 (m, 6H), 7.72 (dd, 2H, J_HH=8.1, J_HP=10.3 Hz), 7.88 ppm

&

Chem. Eur. J. 2015, 21, 1 – 16

www.chemeurj.org

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ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

ÝÝ These are not the final page numbers!

Full Paper

1

(m, 4H); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=17.8 (s), 21.9 (s), 30.3

(s), 55.4 (s), 67.8 (s), 68.2 (s), 70.3 (s), 71.1 (s), 84.2 (s), 86.6 (s), 87.2

(s), 89.0 (s), 95.9 (s), 111.1 (s), 113.9 (s), 125.4 (d, ³J_CP=10.7 Hz),

127.1 (s), 127.9 (d, ³J_CP=9.9 Hz), 130.1 (s, 5), 130.2 (s), 133.8 (s),

134.3 (d, ³J_CP=9.4 Hz), 141.4 (s), 158.2 ppm (s); ³¹P{¹H} NMR

(162 MHz, CDCl₃): d=23.8 ppm (s); FTIR (KBr): n˜ =3457 (m), 3056

(w), 2961 (w), 2360 (w), 1598 (m), 1526 (m), 1459 (w), 1436 (w),

1386 (w), 1288 (w), 1248 (m), 1179 (w), 1095 (w), 1031 (w), 888 (w),

829 (w), 750 (w), 723 (w), 699 (w), 606 (w), 536 cm^ꢀ1(m); HRMS

(ESI): m/z calcd for C₄₅H₄₃ClFeOPRu: 823.11377 [MꢀCl]⁺; found:

823.11398.

(96%). H NMR (400 MHz, CDCl₃): d=0.80–0.94 (m, 144H), 1.70 (br

s, 72H), 2.45 (brs, 24H), 3.25 (brs, 54H), 3.70 (brs, 48H), 4.00 (brs,

48H), 4.09 (brs, 48H), 4.30–4.40 (m, 48H), 5.04 (brs, 96H), 7.02

(brs, 36H), 7.13 (brs, 96H), 7.35 (brs, 144H), 7.63 (brs, 18H),

7.79 ppm (brs, 96H); ¹³C{¹H} NMR (75 MHz, CDCl₃): d=17.2 (s), 21.8

(s), 30.0 (s), 67.8 (brs), 72.7 (m), 73.3 (m), 85.3 (s), 85.9 (s), 90.2 (s),

3

95.0 (s), 109.1 (s), 121.4 (brs), 127.2 (brs), 127.6 (d, J_CP=10.1 Hz),

130.2 (brs), 132.2–132.5 (m), 134.0 (d, ²J_CP=12.1 Hz), 134.6–134.8

(m), 135.5 (s), 136.1 (brs), 136.7 (brs), 148.9 (brs), 151.1–151.3 ppm

(m); ³¹P{¹H} NMR (162 MHz, CDCl₃): d=8.4 (s), 18.7 (s), 62.4 (s),

62.6 ppm (s)

1-(4-(4’-Diphenylphosphino)biphenyl)[(p-cymene)dichlororuthe-

nium(II)]-1’-(4-methoxyphenyl)ferrocene (5b-Ru): Compound 5b

(110.0 mg, 0.18 mmol) was treated with di-m-chlorobis[(p-cyme-

ne)chloro-ruthenium(II)] (48.7 mg, 0.08 mmol) according to the

general procedure. Yield: 156.0 mg (95%). R_f(CH₂Cl₂/ethyl acetate

Complex 8-G₃-Ru: Compound 8-G₃(0.0018 mmol) in CH₂Cl₂(6 mL)

was treated with di-m-chlorobis[(p-cymene)chlororuthenium(II)]

(26.2 mg, 0.043 mmol) to yield an orange powder. Yield: 74 mg

(96%); ¹H NMR (400 MHz, CDCl₃): d=0.88 (m, 288H), 1.68 (brs,

144H), 2.43 (brs, 48H), 3.26 (brs), 3.70 (brs, 96H), 3.95–4.15 (m,

192H), 4.33 (brs, 96H), 5.02 (brs, 192H), 7.03 (brs, 84H), 7.14 (brs,

192H), 7.33 (brs, 288H), 7.66 (brs, 126H), 7.78 ppm (brs, 192H);

¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=17.2 (s), 21.8 (s), 30.0 (s), 67.7

(m), 72.6 (m), 73.3 (m), 77.9 (m), 85.3 (s), 85.9 (brs), 90.1 (brs), 95.0

1

8:1)=0.60. M.p: 1618C; H NMR (400 MHz, CDCl₃): d=1.12 (d, 6H,

3

³J_HH=7.0 Hz), 1.90 (s, 3H), 2.88 (sept, 1H, J_HH=6.9 Hz), 3.66 (s, 3H),

4.19 (m, 2H), 4.25 (m, 2H), 4.42 (m, 2H), 4.51 (m, 2H), 5.03 (dd, 2H,

³J_HH=6.2 Hz, ⁴J_HH=1.4 Hz), 5.23 (d, 2H, ³J_HH=6.1 Hz), 6.68 (d, 2H,

3

³J_HH=8.8 Hz), 7.17 (d, 2H, J_HH=8.7 Hz), 7.30 (d, 2H, J_HH=8.3 Hz),

7.37–7.44 (m, 8H), 7.60 (dd, 2H, ³J_HH=8.5 Hz, ⁴J_HP=2.1 Hz), 7.86–

7.95 ppm (m, 6H); ¹³C{¹H} NMR (75.5 MHz, CDCl₃): d=17.8 (s), 21.9

(s), 30.3 (s), 55.2 (s), 67.4 (s), 67.7 (s), 70.0 (s), 70.5 (s), 85.3 (s), 86.9

(s), 87.2 (d, ²J_CP=5.2 Hz), 89.1 (d, ²J_CP=2.4 Hz), 96.0 (s), 111.2 (d,

3

(brs), 109.1 (s), 121.4 (brs), 127.2 (brs), 127.6 (d, J_CP=9.1 Hz), 130.2

(brs), 132.4 (brs), 133.8–134.2 (m), 135.5 (s), 136.1 (brs), 136.7 (brs),

148.8 (d, ²J_CP=10.1 Hz), 151.1–151.4 ppm (m); ³¹P{¹H} NMR

(162 MHz, CDCl₃): d=8.1 (s), 18.7 (s), 28.4 (s), 62.4 ppm (brs).

Complex 11a-G₁-Ru: Compound 11a-G₁(0.0063 mmol) in CH₂Cl₂

(2 mL) was treated with di-m-chlorobis[(p-cymene)chlororutheniu-

m(II)] (23.5 mg, 0.038 mmol) to yield an orange powder. Yield:

58 mg (79%). ¹H NMR (400 MHz, CDCl₃): d=1.06 (d, ³J_HH=2.8 Hz,

3

²J_CP=2.7 Hz), 113.7 (s), 126.0 (d, J_CP=10.5 Hz), 126.4 (s), 126.8 (s),

127.0 (s), 128.0 (d, ³J_CP=10.1 Hz), 129.6 (s), 130.3 (brs), 131.5 (s),

133.9 (s), 134.3 (d, ²J_CP=9.4 Hz), 135.0 (d, ²J_CP=9.6 Hz), 137.1 (s),

138.0 (s), 142.5 (s), 158.1 ppm (s); ³¹P{¹H} NMR (162 MHz, CDCl₃):

d=23.7 ppm (s); FTIR (KBr): n˜ =3454 (m), 2964 (w), 1631 (m), 1523

(w), 1456 (w), 1261 (w), 1098 (w), 820 (w), 693 (w), 593 (w), 523 (w),

496 (w), 454 (w), 421 cm^ꢀ1(w); HRMS (ESI): m/z calcd for

C₅₁H₄₇ClFeOPRu: 899.14525 [MꢀCl]⁺; found: 899.14444.

3

36H), 1.07 (d, J_HH=2.8 Hz, 36H), 1.82 (s, 36H), 2.81 (m, 12H), 3.22

3

(d, J_HP=10.2 Hz, 18H), 4.06 (br s, 24H), 4.07 (brs, 24H), 4.29 (brs,

24H), 4.36 (brs, 24H), 4.98 (m, 24H), 5.16 (m, 24H), 6.97–7.07 (m,

36H), 7.15–7.22 (m, 48H), 7.34 (brs, 72H), 7.62–7.70 (m, 42H),

7.83 ppm (m, 48H); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=17.7 (s),

21.9 (s), 21.9 (s), 30.3 (s), 33.4 (d, ²J_CP=10.2 Hz), 68.0 (s), 68.1 (s),

71.0 (s), 71.4 (s), 84.3 (s), 85.0 (s), 86.9 (s), 89.2 (s), 95.7 (s), 110.8 (s),

General procedure for the synthesis of the dendritic rutheni-

um complexes

3

121.3 (brs), 125.3 (d, J_CP=10.2 Hz), 127.0 (s), 128.0 (d, J_CP=9.7 Hz),

128.5 (s), 130.2 (brs), 130.7 (s), 133.9–134.4 (m), 135.6 (brs), 138.4

2

(brs), 141.0 (s), 148.8 (d, J_CP=7.1 Hz), 151.2 ppm (brs); ³¹P{¹H} NMR

A solution of the corresponding dendritic ferrocenyl phosphane

dissolved in degassed CH₂Cl₂(4 mL) was added to a solution of di-

m-chlorobis[(p-cymene)chloro-ruthenium(II)] in degassed CH₂Cl₂

(3 mL). The mixture was stirred for 12 h at room temperature, then

concentrated and precipitated into a mixture of hexane/CH₂Cl₂

(4:1, 40:10 mL). After filtration the orange powder was dried under

vacuo.

(162 MHz, CDCl₃): d=8.3 (s), 23.7 (s), 62.6 ppm (s).

Complex 11a-G₂-Ru: Compound 11a-G₂(0.0030 mmol) in CH₂Cl₂

(2 mL) was treated with di-m-chlorobis[(p-cymene)chlororutheniu-

m(II)] (22.0 mg, 0.036 mmol) to yield an orange powder. Yield:

1

53 mg (73%). H NMR (400 MHz, CDCl₃): d=1.06 (brs, 144H), 1.80

(brs, 72H), 2.78 (brs, 24H), 3.22 (brs, 54H), 4.13 (brs, 96H), 4.42

(brs, 96H), 4.96 (brs, 48H), 5.13 (brs, 48H), 7.01–7.81 ppm (br m,

534H); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=17.9 (s), 22.0 (s), 30.3

(s), 33.1 (brs), 68.6 (brs), 71.8 (s), 85.0 (brs), 87.0 (brs), 89.2 (brs),

95.7 (s), 110.8 (s), 121.3 (brs), 121.9 (brs), 125.4 (brs), 127.0 (s),

Complex 8-G₁-Ru: Compound 8-G₁(0.0082 mmol) in CH₂Cl₂(6 mL)

was treated with (30.0 mg, 0.049 mmol) of di-m-chlorobis[(p-cyme-

ne)chlororuthenium(II)] to yield an orange powder. Yield: 79 mg

(91%); ¹H NMR (400 MHz, CDCl₃): d=0.90 (d, 72H, ³J_HH=7.0 Hz),

3

128.0 (d, J_CP=9.6 Hz), 128.7 (s), 130.3 (brs), 130.7 (s), 133.8–134.3

1.72 (s, 36H), 2.48 (sept, 12H), 3.25 (m, 18H), 3.72 (brs, 24H), 4.00

3

(m), 135.5 (brs), 138.4 (brs), 148.8 (brs), 150.0 (s), 151.2 ppm (brs);

³¹P{¹H} NMR (162 MHz, CDCl₃): d=8.3 (s), 24.0 (s), 62.5 (s), 62.8 ppm

(s).

(brs, 24H), 4.08 (brs, 24H), 4.37 (brs, 24H), 5.06 (dd, 48H, J_HP

=

3

15.2, J_HH=5.5 Hz), 6.93 (d, 12H, J_HH=6.6 Hz), 7.01 (d, 24H, J_HH

8.1 Hz), 7.12 (d, ³J_HH=8.1 Hz, 24H), 7.31–7.44 (m, 72H), 7.55–7.70

(m, 18H), 7.81 ppm (dd, 48H, J_HP=8.6, J_HH=8.6 Hz); ¹³C{¹H} NMR

3

Complex 11a-G₃-Ru: Compound 11a-G₃(0.0021 mmol) in CH₂Cl₂

(2 mL) was treated with di-m-chlorobis[(p-cymene)chlororutheniu-

m(II)] (31.0 mg, 0.051 mmol) to yield an orange powder. Yield:

85 mg (82%). ¹H NMR (400 MHz, CDCl₃): d=1.00 (m, 288H), 1.76

(brs, 144H), 2.75 (brs, 48H), 3.19 (brs, 126H), 4.05 (brs, 192H), 4.29

(m, 192H), 4.93 (brs, 96H), 5.10 (brs, 96H), 7.00 (brs, 84H), 7.15

(brs, 288H), 7.28 (brs, 288H), 7.62 (brs, 222H), 7.78 ppm (brs,

192H); ¹³C{¹H} NMR (100.6 MHz, CDCl₃): d=17.8 (s), 21.9 (m), 30.2

(brs), 68.0–68.3 (m), 70.8–71.5 (m), 84.2 (brs), 85.0–85.2 (m), 86.9–

87.1 (m), 89.1–89.4 (m), 95.5 (s), 110.6 (s), 121.3 (brs), 125.2–125.4

(m), 127.0 (brs), 128.0 (d, ³J_CP=11.1 Hz), 130.2 (brs), 130.8 (brs),

(75 MHz, CDCl₃): d=17.2 (s), 21.8 (s), 26.9 (s), 30.0 (s), 67.7 (s), 72.6

2

(s), 73.2 (m), 76.0 (m), 85.3 (s), 85.9 (d, J_CP=5.4 Hz), 90.2 (d, J_CP

=

4

3.1 Hz), 95.0 (s), 109.2 (s), 121.2 (d, J_CP=3.3 Hz), 121.4 (brs), 127.2

(s), 128.2 (d, ³J_CP=9.6 Hz), 128.5 (s), 130.2 (s), 130.8 (s), 134.0 (d,

²J_CP=9.3 Hz), 135.5 (s), 136.2 (s), 136.8 (brs), 148.8 (d, J_CP=7.2 Hz),

2

151.2 ppm (d, ²J_CP=4.3 Hz); ³¹P{¹H} NMR (162 MHz, CDCl₃): d=8.6

(s), 18.7 (s), 62.4 ppm (s).

Complex 8-G₂-Ru: Compound 8-G₂(0.0040 mmol) in CH₂Cl₂(7 mL)

was treated with di-m-chlorobis[(p-cymene)chlororuthenium(II)]

(30.0 mg, 0.049 mmol) to yield an orange powder. Yield: 86 mg

Chem. Eur. J. 2015, 21, 1 – 16

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13

ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

&

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1

133.8 (brs), 134.0–134.4 (m), 135.5 (brs), 140.9 (brs), 148.8 (d, J_CP

=

Theoretical considerations

9.1 Hz), 151.2 ppm (brs); ³¹P{¹H} NMR (162 MHz, CDCl₃): d=7.9 (s),

23.7 (s), 62.6 ppm (s).

For quantum chemical calculations, videlicet geometry optimiza-

tions, and frequency analysis the program suite TURBOMOLE^[24]ver-

sion 6.0 was used. DFT calculations were performed using the BP86

functional^[25]employing the resolution of identity approximation

(RI) and in combination with the basis set Def 2-TZVP.^[26]The con-

vergency criterion was increased to 10^ꢀ8Hartree in all calculations.

The vibrational analyses were carried out using the NUMFORCE

tool. All structures were verified as local energy minima by only

positive eigenvalues of the Hessian matrix. Calculation of the ther-

modynamic potentials was performed by the FREEH tool within

TURBOMOLE. The simulation of the solvent environment was per-

formed using the COSMO model for which the dielectric constant

e was set to 7.58 (THF).

Complex 11b-G₁-Ru: Compound 11b-G₁(0.030 mmol) in CH₂Cl₂

(7 mL) was treated with di-m-chlorobis[(p-cymene)chlororutheniu-

m(II)] (118.2 mg, 0.193 mmol) to yield an orange powder. Yield:

277 mg (75%). ¹H NMR (400 MHz, CDCl₃): d=0.93–1.08 (m, 72H),

1.79 (s, 36H), 2.72–2.85 (m, 12H), 3.06–3.24 (m, 18H), 3.96–4.13 (m,

48H), 4.23–4.44 (m, 48H), 4.90–5.00 (m, 24H), 5.09–5.18 (m, 24H),

6.89–6.99 (m, 36H), 7.03–7.13 (m, 24H), 7.17–7.42 (m, 120H), 7.47–

7.65 (m, 36H), 7.76–7.93 ppm (m, 72H); ¹³C{¹H} NMR (75.5 MHz,

2

CDCl₃): d=17.7 (s), 21.8 (s), 21.8 (s), 30.1 (s), 33.0 (d, J_CP=12.0 Hz),

67.7 (s), 60.7 (s), 70.8 (s) 85.0 (s), 85.0 (s), 87.0 (s), 89.1 (s), 95.7 (s),

110.7 (s), 121.0–121.5 (m), 125.8–126.4 (m), 126.8 (s), 126.9 (s),

3

127.9 (d, J_CP=9.8 Hz), 128.2 (s), 130.1 (brs), 133.8 (d, J_CP=5.8 Hz),

2

134.0–134.3 (m), 134.9 (d, J_CP=9.8 Hz), 135.2 (brs), 137.1 (s), 137.8

(s), 142.2 (s), 148.6 (d, ²J_CP=7.2 Hz), 150.9 ppm (brs); ³¹P{¹H} NMR

(162 MHz, CDCl₃): d=8.5 (s), 23.7 (s), 62.4 ppm (s).

Catalytic transformations

Catalyst preparation and preheating of catalyst with Cs₂CO₃:

The ruthenium complexes were weighed on a Mettler Toledo AB54

fine balance, then dissolved in either THF or DCE (4 mL). Cs₂CO₃

(8.1 mg, 0.025 mmol, 0.625 mol%) was dried under vacuo at 608C

in a Schlenk tube. The catalyst solution was added and the mixture

was stirred at 608C for 5 min. Redox isomerization of 1-octen-3-ol:

1-Octen-3-ol (0.62 mL, 4 mmol) was added through a syringe. The

conversion of 1-octen-3-ol to 3-octanone was determined by GC-

MS (GC samples: 10 mL diluted with 2.5 mL CH₂Cl₂).

Complex 11b-G₂-Ru: Compound 11b-G₂(0.030 mmol) in CH₂Cl₂

(7 mL) was treated with di-m-chlorobis[(p-cymene)chlororutheniu-

m(II)] (111.0 mg, 0.182 mmol) to yield an orange powder. Yield:

1

335 mg (92%). H NMR (400 MHz, CDCl₃): d=0.97–1.10 (m, 144H),

1.81 (brs, 72H), 2.79 (brs, 24H), 3.17 (brs, 54H), 4.09 (brs, 96H),

4.26–4.47 (m, 96H), 4.90–5.00 (m, 24H), 4.97 (brs, 48H), 5.14 (s,

48H), 6.85–7.41 (m, 356H), 7.47–7.67 (m, 106H), 7.75–7.96 ppm (m,

156H); ¹³C{¹H} NMR (75.5 MHz, CDCl₃): d=17.8 (s), 21.9 (s), 30.3 (s),

33.3 (m), 67.9 (s), 70.9 (s), 85.1 (s), 87.1 (s), 89.3 (s), 95.8 (s), 110.8

(s), 121.3 (brs), 126.1–126.2 (m), 126.3 (brs), 127.0 (s), 128.1 (d,

2

³J_CP=9.2 Hz), 130.3 (s), 131.8 (s), 132.2 (s), 133.9 (s), 134.3 (d, J_CP

=

2

7.5 Hz), 134.9 (d, J_CP=7.1 Hz), 135.4 (brs),137.2 (s), 138.0 (s), 142.4

X-ray crystallography

(s), 148.7 (d, J_CP=6.4 Hz), 151.2 ppm (brs); ³¹P{¹H} NMR (162 MHz,

2

Single crystal structure analysis: Data sets were obtained with an

Oxford XCALIBUR S CCD diffractometer. Mo_Kairradiation (l=

71.073 pm) was used for the measurements. Data collection and

data reduction were performed with CrysAlisPro including the pro-

gram SCALE3 ABSPACK for empirical absorption correction.^[27]The

structures were solved with SHELXS-97^[28](Sir92).^[29]Anisotropic re-

finement of all non-hydrogen atoms, except non-coordinating sol-

vent molecules (toluene, n-hexane), was performed with SHELXL-

97. WINGX^[30]was used for the documentation of the structures.

For the visualization Diamond 3^[31]was used. Thermal ellipsoids of

the molecular structures are given at the 50% probability level. De-

tailed crystallographic information of 3, 4a, 9b, 10a, 11 a, and 5a-

Ru are given in the Supporting Information. CCDC-1035704 (3),

CCDC-1035705 (4a), CCDC-1035706 (9b), CCDC-1035707 (10a),

CCDC-1035708 (11 a), and CCDC-1035709 (5a-Ru) contain the sup-

plementary crystallographic data for this paper. These data can be

obtained free of charge from The Cambridge Crystallographic Data

Centre via www.ccdc.cam.ac.uk/data_request/cif.

CDCl₃): d=8.4 (s), 23.7 (s), 62.6 ppm (s).

Complex 11b-G₃-Ru: Compound 11b-G₃(0.010 mmol) in CH₂Cl₂

(7 mL) was treated with di-m-chlorobis[(p-cymene)chlororutheniu-

m(II)] (156.1 mg, 0.255 mmol) to yield an orange powder. Yield:

1

419 mg (77%). H NMR (400 MHz, CDCl₃): d=0.96–1.07 (m, 288H),

1.72–1.82 (m, 144H), 2.77 (brs, 48H), 3.16 (brs, 126H), 4.08 (brs,

192H), 4.22–4.46 (m, 192H), 4.94 (brs, 96H), 5.11 (brs, 96H), 6.85–

7.05 (s, 108H), 7.07–7.39 (m, 656H), 7.46–7.71 (m, 222H), 7.75–

7.96 ppm (m, 280H); ¹³C{¹H} NMR (75.5 MHz, CDCl₃): d=17.8 (s),

21.9 (s), 30.3 (s), 33.3 (m), 67.9 (s), 70.6–71.2 (s), 85.1 (s), 87.1 (brs),

89.3 (brs), 95.7 (brs), 110.7 (brs), 121.3 (brs), 126.0–126.5 (m),

126.7–127.3 (m), 127.7–128.3 (m), 128.9 (brs), 130.3 (brs), 132.1–

132.5 (m), 134.0–134.5 (m), 134.7–135.5 (m), 137.1 (s), 137.9 (s),

142.3 (s), 148.8 (brs), 151.8 ppm (brs); ³¹P{¹H} NMR (162 MHz,

CDCl₃): d=8.0 (s), 23.7 (s), 62.5 ppm (s).

Electrochemistry

Acknowledgements

All measurements were obtained with an AUTOLAB PGSTAT100 po-

tentiostat. Cyclic voltammetry (CV) studies were undertaken in

a two compartment three-electrode cell. The potentials were refer-

enced to a saturated calomel electrode (SCE) Type XR110 from Ra-

diometer Analytical. The type of working electrodes is indicated

within the corresponding measurements. The compounds were

dissolved under N₂atmosphere in either THF or CH₂Cl₂with 0.1m

[n-Bu₄][PF₆] electrolyte prior to each measurement. The solutions

were saturated with N₂by bubbling this gas through the solution

before each run, and the oxidation potentials of the complexes

were measured by CV; at the end, ferrocene was added as an inter-

nal standard with E_1/2=0.56 V (THF) and 0.44 V (CH₂Cl₂).

This work was financially supported by the European Union

and the Free State of Saxony (Landesinnovationspromotion for

P.N.). Support from the Deutsche Forschungsgemeinschaft (He

1376/34-1, joint DFG-ANR project “DENDSWITCH”), COST

Action CM1302 SIPs, and the Graduate School BuildMoNa is

gratefully acknowledged. We thank Chemetall GmbH and Umi-

core AG & Co. KG for generous donations of chemicals and

Prof. B. Kirchner for providing the programme suite TURBO-

MOLE version 6.0.

&

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ÝÝ These are not the final page numbers!

Full Paper

[11] a) B. Helms, J. M. J. Frꢂchet, Adv. Synth. Catal. 2006 , 348 , 112 5 –1 14 8;

b) A.-M. Caminade, A. Ouali, R. Laurent, C.-O. Turrin, J.-P. Majoral, Chem.

Soc. Rev. 2015, in press DOI: 10.1039/C4CS00261J.

Keywords: allylic alcohols

homogeneous catalysis · phosphanes

·

dendrimers

·

ferrocenes

·

[12] I. Angurell, C.-O. Turrin, R. Laurent, V. Maraval, P. Servin, O. Rossell, M.

Seco, A.-M. Caminade, J.-P. Majoral, J. Organomet. Chem. 2007 , 692 ,

192 8 –1 939.

[13] a) C. Janiak, J. Chem. Soc. Dalton Trans. 2000 , 388 5 –3 896; b) C. R. Marti-

nez, B. L. Iverson, Chem. Sci. 2012 , 3 , 219 1 –2 201.

[1] a) R. C. van der Drift, E. Bouwman, E. Drent, J. Organomet. Chem. 2002 ,

650 , 1 –2 4; b) R. Uma, C. Crevisy, R. Grꢂe, Chem. Rev. 2003 , 103 , 2 7 –5 1;

c) V. Cadierno, P. Crochet, J. Gimeno, Synlett 2008, 1105–1124; d) L.

Mantilli, C. Mazet, Chem. Lett. 2011 , 40 , 34 1 –3 44; e) N. Ahlsten, A. Bar-

toszewicz, B. Martin-Matute, Dalton Trans. 2012 , 41 , 166 0 –1 670; f) P.

Lorenzo-Luis, A. Romerosa, M. Serrano-Ruiz, ACS Catal. 2012 , 2 , 107 9 –

1086.

[2] a) B. M. Trost, R. J. Kulawiec, J. Am. Chem. Soc. 1993 , 115 , 202 7 –2 036;

b) D. V. McGrath, R. H. Grubbs, Organometallics 1994 , 13 , 22 4 –2 35; c) V.

Branchadell, C. Crevisy, R. Gree, Chem. Eur. J. 2003 , 9 , 206 2 –2 067; d) V.

Cadierno, S. E. Garcia-Garrido, J. Gimeno, A. Varela-Alvarez, J. A. Sordo, J.

Am. Chem. Soc. 2006 , 128 , 136 0 –1 370; e) N. Ahlsten, B. Martin-Matute,

Adv. Synth. Catal. 2009 , 351 , 265 7 –2 666; f) M. Batuecas, M. A. Esterue-

las, C. Garcia-Yebra, E. Onate, Organometallics 2010 , 29 , 216 6 –2 175.

[3] S. Sahoo, H. Lundberg, M. Edꢂn, N. Ahlsten, W. Wan, X. Zou, B. Martꢃn-

Matute, ChemCatChem 2012 , 4 , 24 3 –2 50.

[4] a) K. Yamaguchi, T. Koike, M. Kotani, M. Matsushita, S. Shinachi, N.

Mizuno, Chem. Eur. J. 2005 , 11 , 657 4 –6 582; b) J. W. Kim, T. Koike, M.

Kotani, K. Yamaguchi, N. Mizuno, Chem. Eur. J. 2008 , 14 , 410 4 –4 109;

c) S. E. Garcꢃa-Garrido, J. Francos, V. Cadierno, J.-M. Basset, V. Polshetti-

war, ChemSusChem 2011 , 4 , 10 4 –1 1 1; d) P. C. L. Menꢂndez-Rodrꢃguez, V.

Cadierno, J. Mol. Catal. A 2013 , 366 , 39 0 –3 99.

[5] a) C. Slugovc, E. Rueba, R. Schmid, K. Kirchner, Organometallics 1999 , 18 ,

423 0 –4 233; b) I. E. Markꢄ, A. Gautier, M. Tsukazaki, A. Llobet, E. Planta-

lech-Mir, C. J. Urch, S. M. Brown, Angew. Chem. Int. Ed. 1999 , 38 , 196 0 –

1962; Angew. Chem. 1999 , 111 , 212 6 –2 128; c) P. Crochet, M. A. Fernan-

dez-Zumel, J. Gimeno, M. Scheele, Organometallics 2006 , 25 , 484 6 –

4849; d) N. Ahlsten, H. Lundberg, B. Martꢃn-Matute, Green Chem. 2010 ,

12 , 162 8 –1 633; e) d. C. A. Pontes, J. A. Mata, B. Royo, E. Peris, Organo-

metallics 2010, 29, 1832–1838; f) V. Bizet, X. Pannecoucke, J.-L. Renaud,

D. Cahard, Angew. Chem. Int. Ed. 2012 , 51 , 646 7 –6 47 0; Angew. Chem.

2012 , 124 , 657 3 –6 576, S6467/6461–S6467/6206.

ˇ

[14] P. Stepnicka, J. Demel, J. Cejka, J. Mol. Catal. A 2004, 224, 161–169.

[15] a) S. Zahn, R. Frank, E. Hey-Hawkins, B. Kirchner, Chem. Eur. J. 2011 , 17 ,

603 4 –6 038; b) S. Scheiner, J. Chem. Phys. 2011 , 134 , 094315; c) S.

Scheiner, Chem. Phys. 2011 , 387 , 7 9 –8 4; d) K. Eskandari, N. Mahmooda-

badi, J. Phys. Chem. A 2013 , 117 , 1301 8 –1 3024.

[16] A. E. Dꢃaz-ꢅlvarez, P. Crochet, M. Zablocka, C. Duhayon, V. Cadierno, J.

Gimeno, J. P. Majoral, Adv. Synth. Catal. 2006 , 348 , 167 1 –1 679.

[17] a) J. E. Bꢆckvall, U. Andreasson, Tetrahedron Lett. 1993 , 34 , 545 9 –5 462;

b) R. Uma, M. K. Davies, C. Crevisy, R. Gree, Eur. J. Org. Chem. 2001 ,

314 1 –3 146; c) V. Cadierno, S. E. Garcia-Garrido, J. Gimeno, Chem.

Commun. 2004 , 23 2 –2 33.

[18] E. E. Joslin, C. L. McMullin, T. B. Gunnoe, T. R. Cundari, M. Sabat, W. H.

Myers, Inorg. Chem. 2012 , 51 , 479 1 –4 801.

[19] a) M. Mammen, S.-K. Chio, G. M. Whitesides, Angew. Chem. Int. Ed. 1998 ,

37 , 275 4 –2 794; Angew. Chem. 1998 , 110 , 290 8 –2 953; b) A. Mulder, J.

Huskens, D. N. Reinhoudt, Org. Biomol. Chem. 2004 , 2 , 340 9 –3 424;

c) P. I. Kitov, D. R. Bundle, J. Am. Chem. Soc. 2003 , 125 , 1627 1 –1 6284.

[20] P. Neumann, H. Dib, A.-M. Caminade, E. Hey-Hawkins, Angew. Chem. Int.

Ed. 2015 , 54 , 31 1 –3 14; Angew. Chem. 2015 , 127 , 31 6 –3 19.

[21] T.-Y. Dong, L.-L. Lai, J. Organomet. Chem. 1996 , 509 , 131.

[22] A. Kçllhofer, H. Plenio, Chem. Eur. J. 2003 , 9 , 141 6 –1 425.

[23] N. Launay, A.-M. Caminade, J. P. Majoral, J. Organomet. Chem. 1997 , 529 ,

5 1 –5 8.

[24] TURBOMOLE V6.5 2013, a development of University of Karlsruhe and

Forschungszentrum Karlsruhe GmbH, TURBOMOLE GmbH, since 2007,

available from http://www.turbomole.com.

[25] a) A. D. Becke, Phys. Rev. A 1988 , 38 , 309 8 –3 10 0; b) J. P. Perdew, Phys.

Rev. B 1986 , 33 , 882 2 –8 824.

[26] F. Weigend, R. Ahlrichs, Phys. Chem. Chem. Phys. 2005 , 7 , 3297.

[27] CrysAlisPro, Data Collection and Data Reduction Software Package In-

cluding SCALE3 ABSPACK for Empirical Absorption Correction using

Spherical Harmonics, version 1.171.135.121, release 120-101-2012 Cry-

sAlis2171.NET, Agilent Technologies.

[28] G. Sheldrick, Acta Crystallogr. Sect. A 2008 , 64 , 11 2 –1 22.

[29] A. Altomare, G. Cascarano, C. Giacovazzo, A. Guagliardi, M. C. Burla, G.

Polidori, M. Camalli, J. Appl. Crystallogr. 1994, 27, 435.

ˇ

[6] J. Schulz, I. Cisarova, P. Stepnicka, Eur. J. Inorg. Chem. 2012 , 500 0 –5 010.

[7] a) M. Ito, S. Kitahara, T. Ikariya, J. Am. Chem. Soc. 2005 , 127 , 617 2 –6 173;

b) A. Bouziane, T. Regnier, F. Carreaux, B. Carboni, C. Bruneau, J.-L.

Renaud, Synlett 2010, 207–210; c) G. Sabitha, S. Nayak, M. Bhikshapathi,

J. S. Yadav, Org. Lett. 2011 , 13 , 38 2 –3 85; d) S. Bovo, A. Scrivanti, M. Ber-

toldini, V. Beghetto, U. Matteoli, Synthesis 2008, 2547–2550; e) N.

Tanaka, T. Suzuki, T. Matsumura, Y. Hosoya, M. Nakada, Angew. Chem. Int.

Ed. 2009 , 48 , 258 0 –2 583; Angew. Chem. 2009 , 121 , 261 8 –2 621.

[8] P. Servin, R. Laurent, L. Gonsalvi, M. Tristany, M. Peruzzini, J.-P. Majoral,

A.-M. Caminade, Dalton Trans. 2009 , 443 2 –4 434.

[30] L. Farrugia, J. Appl. Crystallogr. 2012 , 45 , 84 9 –8 54.

[31] K. Brandenburg, Diamond 3.2i, Bonn, 2012.

[9] a) J.-P. Majoral, A.-M. Caminade, Chem. Rev. 1999 , 99 , 84 5 –8 80; b) A.-M.

Caminade, P. Servin, R. Laurent, J.-P. Majoral, Chem. Soc. Rev. 2008 , 37 ,

5 6 –6 7.

[10] A.-M. Caminade, C.-O. Turrin, R. Laurent, A. Ouali, B. Delavaux-Nicot,

Dendrimers—Towards Catalytic, Material and Biomedical Uses, Wiley,

New York, 2011.

Received: December 15, 2014

Published online on && &&, 2015

Chem. Eur. J. 2015, 21, 1 – 16

www.chemeurj.org

15

ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

&

These are not the final page numbers! ÞÞ

Full Paper

FULL PAPER

Size matters! A homogeneous ruthe-

nium(II) catalyst with a ferrocene-con-

taining monodentate phosphane ligand

is found to efficiently convert 1-octen-3-

ol to 3-octanone (see figure). By grafting

the catalyst to the surface of a dendri-

mer, the catalytic activity is markedly in-

creased. These findings can be ex-

plained by increased stability and multi-

valency of the homogeneous dendritic

catalysts.

&

Homogeneous Catalysis

P. Neumann, H. Dib, A. Sournia-Saquet,

T. Grell, M. Handke, A.-M. Caminade,

E. Hey-Hawkins*

&& – &&

Ruthenium Complexes with Dendritic

Ferrocenyl Phosphanes: Synthesis,

Characterization, and Application in

the Catalytic Redox Isomerization of

Allylic Alcohols

&

Chem. Eur. J. 2015, 21, 1 – 16

www.chemeurj.org

16

ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

ÝÝ These are not the final page numbers!

Article Doi

Ruthenium complexes with dendritic ferrocenyl phosphanes: Synthesis, characterization, and application in the catalytic redox isomerization of allylic alcohols

DOI: 10.1002/chem.201406489

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Article abstract of DOI:10.1002/chem.201406489

Full text of DOI:10.1002/chem.201406489

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