Synthesis of a phosphapyracene via metal-mediated cyclization: Structural and reactivity effects of acenaphthene precursors

Article abstract of DOI:10.1039/c5dt00520e

Metal-mediated synthesis of a new heterocycle, 1-phenyl-phosphapyracene (Ph-4, Ph-PyraPhos), by tandem phosphination/cyclization of peri-substituted 5-bromo-6-chloromethylacenaphthene (3) was investigated for comparison to Pt-catalyzed formation of 1-phosphaacenaphthenes (2, AcePhos) from the analogous naphthalene precursor (1). Reaction of PH₂Ph with 3, NaOSiMe₃ and a Cu catalyst gave Ph-4; a Pt catalyst yielded PHPh(CH₂Ar) (Ph-11, Ar = 5-Br-acenaphthyl). Deprotonation of a complex of this secondary phosphine, [Pt((R,R)-Me-DuPhos)(Ph)(PHPh(CH₂Ar))][PF₆] (17), generated the phosphido intermediate Pt((R,R)-Me-DuPhos)(Ph)(PPhCH₂Ar) (Ph-8), which cyclized to give [Pt((R,R)-Me-DuPhos)(Ph)(Ph-PyraPhos)][PF₆] (18). Treatment of Ph-8 with silver triflate gave 18 and the cyclometalated phosphine complex [Pt((R,R)-Me-DuPhos)(κ²-(P,C)-5-Ph₂PCH₂-6-C₁₂H₈)][PF₆] (21), which might form via Pt(iv) intermediates. The effects of the added "ace" bridge on structure and reactivity are discussed.

Full text of DOI:10.1039/c5dt00520e

View Article Online
View Journal
Dalton
Transactions
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: G. Wang, M.
Guino-o, D. S. Glueck, J. A. Golen, C. J. A. Daley and A. L. Rheingold, Dalton Trans., 2015, DOI:
1
0.1039/C5DT00520E.
This is an Accepted Manuscript, which has been through the
Royal Society of Chemistry peer review process and has been
accepted for publication.
Accepted Manuscripts are published online shortly after
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
Information for Authors.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the Ethical guidelines still
apply. In no event shall the Royal Society of Chemistry be held
responsible for any errors or omissions in this Accepted Manuscript
or any consequences arising from the use of any information it
contains.
www.rsc.org/dalton

Page 1 of 15
Dalton Transactions
View Article Online
DOI: 10.1039/C5DT00520E
Journal Name
RSCPublishing
ARTICLE
Synthesis of a Phosphapyracene via Metal-Mediated
Cyclization: Structural and Reactivity Effects of
Acenaphthene Precursors
Cite this: DOI: 10.1039/x0xx00000x
a
a
a
b
Ge Wang, Marites A. Guinoꢀo, David S. Glueck, * James A. Golen,
b
b
Received 00th January 2012,
Accepted 00th January 2012
Christopher J. A. Daley, and Arnold L. Rheingold
DOI: 10.1039/x0xx00000x
Metalꢀmediated synthesis of a new heterocycle, 1ꢀphenylꢀphosphapyracene (Ph-4, Phꢀ
PyraPhos), by tandem phosphination/cyclization of periꢀsubstituted 5ꢀbromoꢀ6ꢀ
www.rsc.org/
chloromethylacenaphthene (
phosphaacenaphthenes ( , AcePhos) from the analogous naphthalene precursor (
PH Ph with , NaOSiMe and a Cu catalyst gave Ph-4; a Pt catalyst yielded PHPh(CH Ar)
3
) was investigated for comparison to Ptꢀcatalyzed formation of 1ꢀ
2
1
). Reaction of
3
2
3
2
(
[
Ph-11, Ar = 5ꢀBrꢀacenaphthyl). Deprotonation of a complex of this secondary phosphine,
Pt((R,R)ꢀMeꢀDuPhos)(Ph)(PHPh(CH Ar))][PF ] (17), generated the phosphido intermediate
2
6
Pt((R,R)ꢀMeꢀDuPhos)(Ph)(PPhCH Ar)
(
Ph-8), which cyclized to give [Pt((R,R)ꢀMeꢀ
2
DuPhos)(Ph)(PhꢀPyraPhos)][PF ] (18). Treatment of Ph-8 with silver triflate gave 18 and the
6
2
cyclometalated phosphine complex [Pt((R,R)ꢀMeꢀDuPhos)(
κ
ꢀ(P,C)ꢀ5ꢀPh PCH ꢀ6ꢀC H )][PF ]
2
2
12
8
6
(
21), which might form via Pt(IV) intermediates. The effects of the added “ace” bridge on
structure and reactivity are discussed.
Introduction
However, literature precedent suggested that the formal
addition of a twoꢀcarbon “ace” bridge in vs might
3
1
We recently reported platinumꢀcatalyzed asymmetric
tandem phosphination/cyclization of naphthalene to give a
new family of heterocycles, the 1ꢀphosphaacenaphthenes
adversely affect the desired reactivity. Steric strain in
naphthalenes may be relieved by increasing the periꢀdistance
between the 1ꢀ and 8ꢀsubstituents, placing these groups on
opposite sides of the naphthalene plane, and by distorting
1
1
(
AcePhos,
2
, Scheme 1).
Such rigid Pꢀstereogenic
6
phospholanes are potentially useful as ligands in asymmetric
the ring. Adding the “ace” bridge in acenaphthene clamps
2
catalysis. However, further development of this catalytic
the peri substituents together, which commonly increases
7
process was limited because preparation of precursor
1
the periꢀdistance on the other side of the naphthalene. This
3
proceeded in low yield and was difficult to scale up, or
required environmentally unacceptable organomercury
perturbation can have striking structural effects, such as the
difference between a Lewis acidꢀbase adduct in naphthalene
4
8
intermediates.
5 and a frustrated Lewis pair in acenaphthene 6 (Chart 1).
We planned to address this problem by replacing
Similarly, we hypothesized that PꢀC bond formation in
proposed acenaphthene intermediate would be slower than
that in naphthalene because the added bridge would
naphthalene
heterocycles, the 1ꢀphosphapyracenes (PyraPhos,
). This was expected to make the synthesis more
convenient, because 5,6ꢀdibromoacenaphthene, a logical
precursor to , has been prepared from cheap acenaphthene
on 400 g scale.
1
with acenaphthene
3
to yield new
8
4
; Scheme
7
1
increase the separation between the phosphido and aryl
bromide groups and make the structure less flexible
9,10
3
(Scheme 1).
5
This journal is © The Royal Society of Chemistry 2013
J. Name., 2013, 00, 1-3 | 1

Dalton Transactions
Page 2 of 15
View Article Online
ARTICLE
DOI: 10.1039/C5DT00520E
Journal Name
Scheme 1. Proposed effects of replacing naphthalene
1 with acenaphthene 3 in Ptꢀcatalyzed asymmetric synthesis of Pꢀstereogenic
heterocycles: improved precursor synthesis, but slower cyclization of Ptꢀphosphido intermediate
bridge is highlighted in blue)
8 ([Pt] = Pt(DuPhos); the “ace”
Cl
Ph
Br
P
Br
Ph
R
[Pt]
R
PH R
Br
Br
2
P
2
NaOSiMe
3
[
Pt]
Pt catalyst
P
R'
R'
R'
R'
7
1
P
P
AcePhos (2)
R
improved
slower
synthesis?
cyclization?
Ph
P
Cl
[
Pt]
R
Br
P
PH R
R
2
Br
DuPhos
2
NaOSiMe3
(R' = Me or i-Pr)
Ph
Pt catalyst
[
Pt]
8
P
R
3
PyraPhos (4)
5
(adduct)
6 (frustrated)
Ph BMes
2
Ph2P BMes2
2
P
Scheme 2 Synthesis of Benzyl Chloride
3
Br
Br
Br
2
CO H
i. n-BuLi
P–B 2.162(2) Å
31P NMR: δ 12.2
ii. CO2
P–B 3.050(3) Å
31P NMR: δ –9.7
9
i. SOCl
2
i. SOCl
2
Chart 1. Structural effect of naphthalene vs acenaphthene
scaffolds in a phosphine borane (Mes = mesityl)
ii. LiAlH4
iii. H
ii. LiAlH4
iii. conc. HCl
8
2
O
OH
Cl
Br
Br
We report here that acenaphthene precursor
be prepared more conveniently than naphthalene
anticipated, this structural change slowed cyclization,
enabling observation of proposed phosphido intermediate
3
could indeed
MsCl
NEt3
1
.
As
8
10
3
and its conversion to a PyraPhos complex. Although Ptꢀ
catalyzed phosphination/cyclization was not successful, a
simple copper catalyst converted
ring system.
3
to the target PyraPhos
Scheme 3 Phosphination of Benzyl Chloride 3
Cl
PHPh
Br
Br
Results and discussion
PH
NaOSiMe
2
Ph
3
Pt catalyst
Ph
P
2
2
Synthesis and Structure of Acenaphthene 3 and Its
Derivatives
Me
Cl
3
Ph-11
Pt
11
In a oneꢀpot procedure, sequential treatment of the known
carboxylic acid with SOCl , LiAlH , and concentrated HCl
gave benzyl chloride
were similar to those of
of the LiAlH reduction yielded alcohol 10, which reacted
PHPh2
NaOSiMe
Pt catalyst
P
Ph
LiAlH
4
9
3
2
4
PPh(O-iPr)2
Pt catalyst
1
13
Me
3
SiCl
3
, whose H and C NMR spectra
O
P
1
1
. Alternatively, aqueous workup
PPh
2
O-i-Pr
Ph
Br
Br
4
with mesyl chloride and NEt in CH Cl to form
3 (Scheme
3
2
2
1
2
).
Ptꢀcatalyzed phosphination of benzyl chloride
or PHPh gave secondary and tertiary phosphines Ph-11 and
3
with PH Ph
12
13
2
2
12,13
14
1
2
, respectively,
while an Arbuzov reaction yielded
Comparison of the crystal structures of the acenaphthenes
3,
phosphine oxide 13, which could be reduced to 11 with
Ph-11, and 13 to those of and related naphthalenes (see
Figures 1ꢀ2, Table 1, and the ESI) revealed the expected
1
15
LiAlH /SiMe Cl (Scheme 3).
4
3
2
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012

Page 3 of 15
Journal Name
Dalton Transactions
View Article Online
ART20ICLE
DOI: 10.1039/C5DT005 E
differences, as described in the introduction. In particular,
the periꢀdistances (C1ꢀBr) increased slightly in the
acenaphthenes, as the added “ace” bridge reduced the
“bottom” CCC’ angle and increased the “top” CCC one
(
Table 1).
Figure 1. ORTEP diagram of acenaphthene
3
Figure 2 ORTEP diagram of the secondary phosphine Ph-
Except for the PꢀH, which was located and refined,
11.
hydrogen atoms are not shown.
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 3

Dalton Transactions
Page 4 of 15
View Article Online
ARTICLE
DOI: 10.1039/C5DT00520E
Journal Name
a
Table 1. Selected Structural Data for Naphthalene and Acenaphthene Derivatives
E
X
peri-distance
peri-distance
Br
P
Ph
CCC angle
CCC' angle
CCC angle
CCC' angle
b
c
Type
N
A
N
A
X or E (#)
CCC angle CCC’ angle Displacement peri-distance
d
X = Cl (1)
X = Cl (3)
128.1(3)
130.6(5)
128.4(3)
131.1(3)
131.8(3)
131.5(3)
118.2(3)
110.4(6)
118.9(3)
111.2(3)
111.1(2)
110.5(3)
0.145, –0.175
0.097, –0.15
0.073, –0.11
0.16, –0.15
0.52, –0.45
0.048, 0.13
3.156
3.238
3.172
3.22
3.255
3.249
e
X = PHPh(BH3)
X = PHPh (Ph-11)
A
A
X = PPh(O)(OꢀiꢀPr) (13)
f
X = PPh(BH ) (15)
3
0
.27, –0.12
+
g
A
N
A
X = [PPh (Pt(MeꢀDuPhos))] (21)
128.7(7)
117.3(2)
122.0(8)
112.2(7)
125.3(3)
114.3(8)
0.63, –0.23
0.025, –0.065
–0.048, 0.46
3.272
1.852(3)
1.851(8)
2
h
E = BH3
i
E = BH (14)
3
–
0.045, ꢀ0.10
0.24, 0.04
A
A
E = O•0.5H O (16•0.5H O )
E = [Pt(MeꢀDuPhos)(Ph)] (18a)
120.42(2)
120.8(3)
115.01(12)
115.5(3)
1.8445(13)
1.861(3)
2
2
2
2
+
0.094, 0.11
a
b
c
Distances in Å, angles in degrees N = naphthalene, A = acenaphthene Displacement of the periꢀsubstituents (either Br and C,
or P and C) from the naphthalene or acenaphthene plane. Plus and minus signs indicate displacement on opposite sides of the
naphthalene (acenaphthene) plane. Average values are reported, except in some cases where displacements differed significantly
d
for the two molecules in the unit cell, or where there are two acenaphthyl groups in 15 Average values for the two molecules in
e
f
g
the unit cell Ref 1 average values for the two bromoacenaphthenyl groups, except for the displacements Chelate complex;
+
h
bromide was replaced by [Pt(MeꢀDuPhos)(PPh CH Ar)] . Displacements are reported for Pt and C, respectively. Average values
for the two molecules in the unit cell (Ref 1) Average values for the two enantiomeric forms in the disordered crystal, except for
the displacements.
2
2
i
Metal-Mediated Phosphination and Cyclization of 3:
Synthesis and Structure of Ph-PyraPhos Derivatives
Despite these small structural changes, and the spectroscopic
similarity between naphthalene and acenaphthene
Scheme
Phosphination/Cyclization of
Pt((R,R)ꢀMeꢀDuPhos)(Ph)(Cl))
4
.
Attempted
PtꢀCatalyzed
(Catalyst Precursor =
Tandem
3
Cl
PHR
derivatives
which smoothly converted
for , consistent with the structural hypothesis of Scheme 1.
1
and
3
, the oneꢀpot Ptꢀcatalyzed tandem process
Br
Br
P
R
1
to AcePhos was much slower
2
PH R
2
2
NaOSiMe3
slow
3
Pt catalyst
With a variety of primary phosphines, this reaction gave
mostly the expected intermediate secondary phosphine 11
3
11
4
and little of PyraPhos
4 (Scheme 4; see the ESI for details).
In contrast, conversion of
3 to PhꢀPyraPhos (Ph-4)
proceeded smoothly with PH Ph, NaOSiMe and the catalyst
2
3
precursor CuCl, via the intermediate secondary phosphine
16
Ph-11 (Scheme 5). After addition of BH (THF), Phꢀ
3
4
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012

Page 5 of 15
Journal Name
Dalton Transactions
View Article Online
ART20ICLE
DOI: 10.1039/C5DT005 E
PyraPhos(BH ) (14, Figure 3 and Table 1) was isolated in
3
7
(
4
6% yield after chromatographic separation from a minor
<5%) byproduct, the tertiary phosphineꢀborane 15 (Figure
see Table for structural comparison to other
acenaphthene derivatives). Deprotection of 14 using an
;
1
17
amineꢀfunctionalized polymer gave pure Ph-4
,
which was
oxidized slowly by air to yield the phosphine oxide 16
.
Faster oxidation with hydrogen peroxide gave a hydrogenꢀ
bonded H O adduct, from which H O could be removed
2
2
2
2
18
with molecular sieves (see the ESI for details). Although
the P NMR chemical shifts of precursors Ph-11 and its
3
1
naphthalene analogue were identical, those of PhꢀPyraPhos
(
Ph-4
, δ –5.6) and PhꢀAcePhos (Ph-2, δ –15.1) were
somewhat different, as also observed for their borane
1
adducts (
δ
35.8 and 28.8, respectively).
Scheme
5
.
Copperꢀcatalyzed
Tandem
Phosphination/Cyclization of
3
Cl
Br
PHPh
Br
3
i. PH Ph
Ph-11, intermediate
2
2
NaOSiMe
cat. CuCl
ii. BH (THF)
3
3
BH
3
Ph
P
Br
P
Ph
BH3
Br
+
1
4
15, minor
major
piperazinomethyl
polystyrene
ꢀ
O
P
P
Ph
Ph
2 2
H O
or air
Ph-4
16
Figure 3. ORTEP diagram of PhꢀPyraPhos(BH ) (14). The
3
crystal was disordered, with both enantiomers appearing in
an 80:20 ratio. The major form is shown in the figure. The
disorder does not represent the enantiopurity of the
compound; the sample was racemic as determined from the
centrosymmetric space group solution.
The structures of 14 and 16•0.5H O (ESI) were similar to
2
2
that of the previously characterized phosphaacenaphthene
1
analogue, PhꢀAcePhos(BH ) (Table 1). As expected, P–C
3
bond formation resulted in drastically shorter periꢀdistances,
and reduced displacement of these substituents from the
acenaphthene plane.
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 5

Dalton Transactions
Page 6 of 15
View Article Online
ARTICLE
DOI: 10.1039/C T00520E
Jou5Drnal Name
Scheme 6 Formation of Cationic PhꢀPyraPhos Complex 18
via Cyclization of Phosphido Intermediate Ph-8 ([Pt] =
Pt((R,R)ꢀMeꢀDuPhos))
PF6
PHPh
Br
Br
Ph
P
[
Pt]
[Pt](Ph)(Cl)
H
NH PF6
4
Ph
Ph-11
17, 2 diastereomers
NaOSiMe
Br
3
PF6
Ph
P
[
Pt]
Ph
P
[Pt]
Ph
Ph
18, 2 diastereomers
Ph-8, 2 diastereomers
NH
4
PF
6
[NOct
Ph
4
][Br]
BH
P
3
P
Ph
Br
Ph
[
Pt]
+
1
9
3
BH (THF)
Ph-4
14
The major diastereomer 18a was isolated by
Figure 4. ORTEP diagram of tertiary phosphineꢀborane 15
recrystallization, and Xꢀray crystallography showed it
contained
RꢀPhꢀPyraPhos (Figure 5). Replacing BH in 14
3
Platinum-Mediated Formation of Ph-PyraPhos Ph-4 via
Cyclization of Phosphido Complex Ph-8
with the bulky Ptꢀsubstituent had little effect on the structure
of the PyraPhos group in 18a (Table 1).
To investigate the slow Ptꢀcatalyzed synthesis of PyraPhos
derivatives, we sought to generate the proposed Ptꢀ
phosphido intermediate (
8
, Scheme 1) and to observe the
cyclization step directly.
Treatment of Pt((R,R)ꢀMeꢀ
DuPhos)(Ph)(Cl) with secondary phosphine Ph-11 and
NH PF gave cation 17 as 1.5:1 mixture of
Deprotonation of 17 with NaOSiMe3
a
4
6
19
diastereomers.
generated phosphido complex Ph-8 as a ca. 2:1 mixture of
diastereomers, consistent with the hypothesis that adding the
“
ace” bridge would slow ring formation (the related Pt(iꢀPrꢀ
DuPhos) intermediate Ph-7 had not been observed in the
naphthalene series). Cyclization of Ph-8 occurred at room
temperature to give an apparent equilibrium mixture of
cationic PhꢀPyraPhos complex 18 (two diastereomers in
ratios varying from 1.4:1 to 5:1), PhꢀPyraPhos Ph-4, and the
20
known PtꢀBr complex 19 (Scheme 6). These products
always formed over multiple experiments using different
batches of 17, but the rate of cyclization and the ratio of
diastereomers 18a/18b was erratic and poorly reproducible,
and we have not been able to discover the reason(s) for this
variability (see the ESI). Adding NH PF to the product
4
6
mixture promoted PhꢀPyraPhos complexation to give 18
.
Alternatively, treatment with excess [NOct ][Br] shifted the
equilibrium to favor Ptꢀbromide complex 19 and Phꢀ
PyraPhos (Ph-4), which was isolated after addition of
Figure 5.
DuPhos)(Ph)((
not shown.
ORTEP diagram of [Pt((R,R)ꢀMeꢀ
4
R
)ꢀPhꢀPyraPhos)][PF ] (18a). The anion is
6
BH (THF) as the borane complex 14 (Scheme 6).
3
6
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012

Page 7 of 15
Journal Name
Dalton Transactions
View Article Online
DOI: 10.1039/C5DT0
A
0
R
5
T
20IC
E
LE
Cation 18 was prepared independently as a 1:1 mixture of
diastereomers by treatment of Pt((R,R)ꢀMeꢀDuPhos)(Ph)(Cl)
with racemic PhꢀPyraPhos (Ph-4) and NH PF (Scheme 7,
Scheme 8.
Possible Mechanism for Cyclization of Ptꢀ
phosphido Complex Ph-8 ([Pt] = Pt((R,R)ꢀMeꢀDuPhos))
4
6
Ph
Ph
PF6
Ph
[Pt]
top). Reaction of Pt((S,S)ꢀMeꢀDuPhos)(Ph)(Cl) with
NH PF and ꢀPhꢀPyraPhos (isolated after liberation from
highly diastereoenriched 18a; see the ESI) gave [Pt((S,S)ꢀ
MeꢀDuPhos)(Ph)( ꢀPhꢀPyraPhos)][PF6] 18b’), the
Br
P
R
PF
6
4
6
[Pt]
P
H
R
(
Ph
enantiomer of 18b (Scheme 7, bottom), so that highly
enriched samples of both diastereomers could be
characterized spectroscopically.
17
1
8
NaOSiMe
3
Ph
NaPF
6
[
Pt]
Ph
Ph
P
P
Br
Ph
Pt
Scheme 7 Synthesis of PhꢀPyraPhos Complex 18 By
Complexation of PhꢀPyraPhos Ph-4 ([Pt] = Pt((R,R)ꢀMeꢀ
DuPhos) (top) or Pt((S,S)ꢀMeꢀDuPhos) (bottom))
P
P
Br
20
Ph-8
Ph
[Pt]
with
P
(
R,R)-Me-DuPhos
Ph
Cl
Scheme 9. Reaction of PtꢀPhosphido Complex Ph-8 with
Silver Triflate Gave a Mixture of Products, Including
Cyclometalated 21, Which Was Prepared Independently by
Oxidative Addition of Bifunctional Phosphine 12 to Pt(0)
racemic
Ph-4
NH PF
4
6
Ph
P
Ph
P
(
[Pt] = Pt((R,R)ꢀMeꢀDuPhos))
[
Pt]
Ph
[Pt]
Ph
PF6
+
PF
Ar
6
Ph
P
[
Pt]
Ph
P
Ph
[
Pt]
PF
6
1
7
H
PF6
1
8a
18b
Ph
NaOSiMe
3
Br
Ph
Ph
P
[
Pt]
Ph
[
Pt]
P
AgOTf
Ph
18
Ph
P
enriched R-Ph-4
NH PF
Ph-8
Pt
+
+ 22
Cl
Ph
P
4
6
Ph
Ph
PPh
2
Br
P
with
S,S)-Me-DuPhos
PF
6
i. [Pt]
Ph
ii. NH PF
(
[Pt]
PF6
18b'
4
6
Cyclization of phosphido intermediate Ph-8 might proceed
by C–Br oxidative addition to yield octahedral Pt(IV)
1
2
2
1
complex 20
.
P–C reductive elimination, following
dissociation of bromide, would then form PtꢀPhꢀPyraPhos
The structure of 21 was confirmed by independent synthesis
–
cation 18, in which the PF anion is derived from precursor
(Scheme 9). Oxidative addition of phosphineꢀfunctionalized
6
21
22
1
7
(Scheme 8). To test this hypothesis, we added a silver
salt to abstract bromide from putative intermediate 20
Treatment of yellow THF solution of phosphido
aryl bromide 12 to Pt((R,R)ꢀMeꢀDuPhos)(transꢀstilbene),
.
followed by anion exchange with NH PF , gave 21, whose
4
6
a
crystal structure (Figure 6, Table 1, and ESI) confirmed the
intermediate Ph-8 with silver triflate resulted in immediate
darkening of the reaction mixture, followed by formation of
a precipitate. Complex Ph-8 was immediately converted to
unidentified longꢀlived intermediates, which over a few days
formed a mixture of cyclometalated 21 (major product), Phꢀ
PyraPhos complex 18 and another unidentified [Pt(Meꢀ
cyclometalation and the presence of the PPh group. The
acenaphthene ring in 21 was structurally similar to the
analogues in Table 1, with larger displacements of the bulky
2
periꢀsubstituents to opposite sides of the ring.
The
acenaphthene also showed small distortions from planarity,
ranging from 0.16 Å (C19) to –0.14 Å (C30). Although the
role of AgOTf in the selectivity of cyclization of Ph-8 is
unclear, both cations 21 and 18 could form from Pt(IV)
intermediates as in Scheme 8.
+
DuPhos)(phosphine)(X)] cation (22; Scheme 9, see the
Experimental section and ESI for details).
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 7

Dalton Transactions
Page 8 of 15
View Article Online
ARTICLE
DOI: 10.1039/C T00520E
Jou5Drnal Name
were from commercial suppliers. The following compounds
were made by literature methods or their modifications
5
(
ESI): 5,6ꢀdibromoacenaphthene, 6ꢀbromoꢀ5ꢀacenaphthoic
25,11
acid (
9
),
Pt((R,R)ꢀMeꢀDuphos)(Ph)(Cl) and Pt((S,S)ꢀMeꢀ
Duphos)(Ph)(Cl), Pt(dppe)(Me)(Cl), and Pt((R,R)ꢀMeꢀ
Duphos)(transꢀstilbene).
Benzyl chloride 3 was prepared by a modification of the
procedure reported for the naphthalene derivative. Under
N , SOCl (6.73 mL, 92.5 mmol, 12 equiv) was added via a
26
27
2
2
4
a
2
2
syringe to carboxylic acid
9 (2.136 g, 7.71 mmol). The
mixture was heated to reflux with stirring at 70 °C for 3 h;
the solid dissolved to give a deep green solution. After
cooling to room temperature, the excess SOCl was removed
2
under vacuum to give a grey solid, which was dissolved in
1
50 mL of ether. Under positive N flow, solid LiAlH (322
2 4
mg, 8.47 mmol, 1.1 equiv) was added to give a white
suspension, which was refluxed at 33 °C for 36 h. The flask
was cooled in an iceꢀwater bath, and 15 mL of conc HCl was
added dropwise. The mixture was stirred overnight, then
filtered through Celite. The organic layer was separated and
Figure 6. ORTEP diagram of the cation in [Pt((R,R)ꢀMeꢀ
2
DuPhos)(
κ
ꢀ(P,C)ꢀ5ꢀPPh CH ꢀ6ꢀC H )][PF ] (21). The
2
2
12
8
6
washed with water, aqueous NaHCO , and water again, then
anion is not shown.
3
dried with MgSO . Removal of the solvent with a rotary
4
Conclusions
evaporator gave the crude product as a white solid.
Recrystallization from ether gave 1.026 g of pure white
crystals (47% yield).
As expected, the synthesis of acenaphthene precursor
more convenient than that of naphthalene
3
was
We
1
.
Anal. Calcd. for C H BrCl: C, 55.45; H, 3.58; Found C,
1
3
10
hypothesized that the added “ace” bridge would slow ring
formation, but were surprised by the large effect of this
small structural change, which enabled observation of Ptꢀ
5
5.54; H, 3.57. HRMS m/z calcd for C H BrCl: 279.9654.
13 10
1
Found: m/z 279.9652. H NMR (CDCl ):
δ
7.79 (d,
J
J
= 7,
= 7,
3
1
1
1
1
H), 7.57 (d, J = 7, 1H), 7.28 (d, J = 7, 1H), 7.15 (d,
H), 5.48 (2H), 3.36 (m, 4H). C{ H} NMR (CDCl ):
1
3
1
phosphido intermediate Ph-8 and its cyclization to 18
While this drastic change in reactivity precluded Ptꢀ
catalyzed reactions, copperꢀcatalyzed tandem
.
δ
3
49.1, 147.1, 141.9, 135.3, 133.9, 129.9, 128.3, 121.0,
20.2, 113.6, 46.3, 30.5, 30.2.
phosphination/cyclization yielded the desired heterocycle,
PhꢀPyraPhos (Ph-4). We hope to apply these observations
to develop copperꢀcatalyzed asymmetric synthesis of
Secondary Phosphine Ph-11 A solution of PH Ph (0.028 g,
2
0
.25 mmol, 1 equiv) in 1 mL of THF was added to a mixture
of NaOSiMe (0.055 g, 0.50 mmol, 2 equiv in 1 mL of THF;
3
23
PyraPhos derivatives.
note, this excess of base was not required, and 1 equiv also
worked well) and Pt(dppe)(Me)(Cl) (0.008 g, 0.01 mmol,
0.05 equiv in 1 mL of THF) resulting in a light yellow
Experimental
solution. A solution of benzyl chloride
mmol, 1 equiv) in 1 mL of THF was added, yielding an
orange solution. The mixture was stirred overnight and the
3 (0.071 g, 0.25
General Experimental Details. Unless otherwise noted, all
reactions and manipulations were performed in dry
glassware under
a nitrogen atmosphere at ambient
solvent was removed in vacuo
.
The yellow solid was
temperature in a dry box or using standard Schlenk
techniques. Petroleum ether (bp 38ꢀ53 °C), CH Cl , ether,
dissolved in 10 mL of 10% toluene/petroleum ether and the
solution was filtered through a silica plug, which was
washed with 20ꢀ40 mL of the solvent mixture. Removing
the solvent from the filtrate in vacuo gave a white solid
2
2
THF, and toluene were dried over alumina columns similar
24
to those described by Grubbs. NMR spectra were recorded
1
13
by using 300, 500 or 600 MHz spectrometers. H or
C
(
0.080 g, 89% yield). Alternatively, the solid residue was
NMR chemical shifts are reported vs Me Si and were
4
extracted with 5ꢀ10 mL of ether, and the solution was
filtered through Celite to give a clear yellow solution, which
was cooled to –25 °C in a refrigerator. A white precipitate
formed after one day. The solvent was decanted and the
white solid was dried in vacuo to give spectroscopically pure
product.
1
13
determined by reference to the residual H or C solvent
3
1
peaks.
P NMR chemical shifts are reported vs H PO4
3
(
85%) used as an external reference. Coupling constants are
reported in Hz, as absolute values unless noted otherwise.
Unless indicated, peaks in NMR spectra are singlets.
Quantitative Technologies Incorporated provided elemental
analyses. Mass spectrometry was performed at the
University of Illinois. Unless otherwise noted, reagents
Elemental analysis was consistent with oxidation of the airꢀ
sensitive phosphine. Anal. Calcd. for C H BrP: C, 64.24;
1
9
16
H, 4.54; Anal. Calcd. for C H BrOP: C, 61.48; H, 4.34.
19
16
8
| J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012

Page 9 of 15
Journal Name
Dalton Transactions
View Article Online
ART20ICLE
DOI: 10.1039/C5DT005 E
Found: C, 61.18; H, 4.02. HRMS m/z calcd for C H BrP:
Copper-Catalyzed Reaction of Benzyl Chloride 3 with
PH Ph and NaOSiMe to Give Ph-PyraPhos(BH ) (14)
and PhP(CH Ar) (BH ) (15) A solution of NaOSiMe3
2 2 3
(437 mg, 3.9 mmol, 2.2 equiv) in 2 mL of THF was added to
a solution of CuCl (9 mg, 0.09 mmol, 5 mol %) in 1 mL of
1
9
16
3
1
3
55.0251. Found: m/z 355.0254. P NMR (C D ):
δ
–36.2
6
6
2
3
3
3
1
1
(
d,
J
= 210). P NMR (CDCl3):
8.03ꢀ8.02 (d,
.56 (1H), 7.48ꢀ7.41 (m, 4H), 7.03ꢀ7.01 (dt,
.14ꢀ5.11, 4.78ꢀ4.69, 4.17ꢀ4.13 (m, PH and CH , 3H), 3.22ꢀ
δ
–37.0 (d,
J
= 214).
H
NMR (C D ):
δ
J
= 7, 1H), 7.73ꢀ7.69 (m, 2H),
= 2, 7, 1H),
6
6
7
5
3
1
6
1
δ
1
1
2
J
THF. A solution of PH Ph (195 mg, 1.77 mmol) in 2 mL of
2
2
1
.12 (m, 4H). H NMR (CDCl ):
δ
7.71ꢀ7.70 (dd,
H), 7.37ꢀ7.24 (m, 3H), 7.07ꢀ7.02 (m, = 7, 21, 3H), 6.86ꢀ
.85 (m, 2H), 4.32 (dt, = 6, 214, PH, 1H), 4.26ꢀ4.21 (m,
H), 3.77ꢀ3.73 (m, 1H), 3.30 (4H). C{ H} NMR (CDCl ):
J
= 2, 7,
THF was added to the yellow mixture, which turned dark
3
J
red. A solution of benzyl chloride
3 (499 mg, 1.77 mmol) in
J
2 mL of THF was added, giving the mixture a dark brown
1
3
1
31
color. The reaction was monitored by
P
NMR
3
3
1
147.0, 145.3 (d,
J
= 2), 141.9, 135.3 (d,
J
= 13), 134.31,
= 4),
J = 2), 114.1, 30.7 (d, J = 15), 30.0,
spectroscopy. After 20 min of stirring, P NMR integration
showed about 40% conversion of the starting primary
phosphine to the intermediate secondary phosphine Ph-11 (δ
ꢀ36.9 in THF). After 2.5 h, almost all the primary phosphine
was converted to secondary phosphine, and a peak due to
PhꢀPyraPhos Ph-4 also appeared (δ ꢀ5.5). The reaction was
34.3 (d, = 3), 131.75, 131.71, 131.6, 128.2 (d,
J
J
28.19, 120.1, 119.7 (d,
9.9.
Tertiary Phosphine 12 A solution of PHPh (67 mg, 0.36
2
mmol, 1 equiv) in 1 mL of THF was added to a mixture of
3
1
NaOSiMe (44 mg, 0.39 mmol, 1.1 equiv in 1 mL of THF)
done in 7 h. P NMR signals due to impurities were
observed at δ ꢀ10.2 (4%), ꢀ12.9 (1%) and ꢀ14.3 (1%). Under
positive N pressure, 2.7 mL of a BH ꢀTHF solution (1 M in
3
and Pt(dppe)(Me)(Cl) (11 mg, 0.017 mmol, 0.05 equiv in 1
mL of THF) resulting in a yellow solution. To this mixture,
2
3
a solution of benzyl chloride
3
(100 mg, 0.36 mmol, 1
THF, 2.7 mmol, 1.5 equiv) was added dropwise by syringe
to the dark brown mixture, which was stirred for 2 min. The
P NMR spectrum confirmed the formation of 14 (δ 36.8,
equiv) in 1 mL of THF was added. Stirring at room
temperature for 22 h gave a light yellow suspension. The
solvent was removed under vacuum, and the light pink
residue was extracted with ether (8 x 3 mL). The extract was
filtered through a Celite plug to give a clear solution, which
was pumped down under vacuum to give 130 mg (85%
yield) of crude product as a mixture of white solid at the
bottom of the vial and light yellow solid on the walls. The
white solid (43 mg) was carefully separated with a spatula,
and shown to be pure by NMR spectroscopy. The light
yellow solid was extracted with 12 mL of ether. The extract
was filtered through a Celite plug to give a clear solution
which was cooled to ꢀ20 °C. A white precipitate formed
after one day. The solvent was decanted and the white solid
was dried under vacuum to give 54 mg of product, which
3
1
apparent d,
21.6, 2%).
J = 53) as well as side products (δ 23.4, 3%; δ
Aqueous NH Cl (20 mL of 1 M solution) and 20 mL of
4
ether were added slowly to the deep brown mixture, which
was stirred for 5 min and filtered through Celite. The
product was extracted with 2×20 mL of ether. The organic
layer was collected and dried with MgSO . Removing the
4
solvent under reduced pressure gave a sticky brown oil. This
crude product was purified by chromatography on silica (Rf
= 0.28 in 10:1 hexane/ethyl acetate). Since the product
decomposes on the column, chromatography needs to be
done quickly. The minor product 15 had similar polarity (Rf
=
0.21 in 10:1 hexane/ethyl acetate). Repeated
3
1
1
contained about 8% of the phosphine oxide ( P{ H} NMR
CDCl3): 29.4; this signal grew significantly after the
chromatography gave a total of 390 mg (76% yield) of white
solid. Vapor diffusion of hexane into an ether solution at
room temperature gave transparent crystals after 4 d.
(
δ
NMR sample was exposed to air overnight). A portion of the
above sample (39 mg) was dissolved in CH Cl and passed
through a silica plug to remove the phosphine oxide. After
removal of the solvent, 24 mg of pure white solid was
obtained (total yield = 67 mg (44%)).
Anal. Calcd for C H PB: C, 79.20; H, 6.30; Found: C,
2
2
19 18
+
78.93; H, 6.07. HRMS (m/z): calcd for C H PB (MꢀH) ,
19
17
3
1
1
287.1161, found, 287.1169. P{ H} NMR (CDCl ): δ 35.8
3
1
(apparent d, J = 61). H NMR (CDCl ): δ 7.73 (t, J = 7, 1H),
3
Anal. Calcd for C H BrP: C, 69.62; H, 4.67; Found: C,
7.57ꢀ7.53 (m, 2H), 7.46ꢀ7.41 (m, 3H), 7.37ꢀ7.34 (m, 3H),
3.85 (AB q, JAB = 18, 1H, benzyl), 3.65 (ABX, JAB = 18, JAX
= 9, 1H, benzyl), 3.53ꢀ3.48 (m, 4H, ace H), 1.6ꢀ0.8 (m,
2
5
20
+
6
4
9.10; H, 4.42. HRMS (m/z): calcd for C H BrP (MH) :
25 21
3
1
1
31.0564; found, 431.0562. P{ H} NMR (CDCl ):
δ
–9.6.
= 7, 1H), 7.46ꢀ7.42 (m, 4H),
= 7, 1H), 6.94 (d, = 7, 1H),
= 3, 7, 1H), 4.35 (2H, benzyl CH ), 3.32 (4H,
3
1
13
1
H NMR (CDCl3):
δ
7.76 (d,
.37ꢀ7.33 (m, 6H), 7.10 (d,
.64 (dd,
J
broad, 3H, BH3). C{ H} NMR (CDCl ): δ 148.9 (d,
Ar, quat), 143.8 (Ar, quat), 138.9 (d, J
J
= 2,
= 15, Ar, quat), 138.6
= 8, Ar, quat), 132.3 (Ar, quat), 132.0 (Ar, quat), 131.9
= 10, Ar), 131.6 (d, = 3, Ar), 129.9 (d, = 10, Ar),
= 10, Ar), 127.3 (d, = 57, Ar, quat), 125.4 (d,
= 7, Ar), 121.8 (d, = 11, Ar), 121.3 (Ar), 34.8 (d,
benzyl CH ), 32.0 (d, = 1, aceꢀCH ), 31.3 (aceꢀCH ).
3
7
6
J
J
J
1
(d,
(d,
J
J
2
3
1
aceꢀCH2). C{ H} NMR (CDCl ):
δ
146.8 (Ar, quat), 145.5
J
J
3
(
d,
J
= 3, Ar, quat), 141.8 (d,
7, Ar, quat), 134.5 (Ar), 133.3 (d,
, Ar), 129.5 (d, = 9, Ar, quat), 128.8 (d,
28.5 (Ar), 128.2 (d, = 6, Ar), 120.1 (Ar), 119.6 (d,
= 15, benzylꢀCH ), 30.0
J
= 2, Ar, quat), 138.6 (d,
J
J
=
=
129.0 (d,
J
J
J
1
8
1
J
= 18, Ar), 132.3 (d,
J
J
= 40,
J
J
= 3, Ar, quat),
= 2,
J
2
2
2
J
J
In a similar reaction starting with 862 mg (3.06 mmol) of
benzyl chloride , 15 mg (0.024 mmol, 1.6% yield) of the
Ar), 114.5 (Ar, quat), 35.3 (d,
aceꢀCH ), 29.9 (aceꢀCH ).
J
3
2
(
minor product 15 was separated through chromatography
2
2
and characterized spectroscopically. Although this material
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 9

Dalton Transactions
Page 10 of 15
View Article Online
ARTICLE
DOI: 10.1039/C5DT00520E
Journal Name
3
1
was not obtained in analytically pure form, slow evaporation
of the chromatographic eluent (20:1 hexane/ethyl acetate)
gave small Xꢀray quality crystals.
reaction was checked by P NMR to ensure correct
stoichiometry before further workup. The mixture was
filtered through Celite. The solvent was pumped off, giving
a white powder (158 mg, 104% yield of crude product which
+
HRMS (m/z): calcd for C H BrPB (MꢀH Br) , 531.1049,
3
2
26
2
3
1
1
31
found, 531.1060. P{ H} NMR (CDCl ): δ 22.3 (apparent
contained THF), which was pure according to P NMR
3
d,
J
= 53), plus an unidentified peak at δ 20.9 (10%,
spectroscopy. This material was a 1.5:1 mixture of
diastereomers. Recrystallization by vapor diffusion of
pentane into a THF solution at ꢀ20 °C for 3 d gave white
crystals. This reaction was also run with 0.632 g of Pt
starting material to give 1.103 g of crude product (99%
1
apparent d,
J
= 71). H NMR (CDCl ): δ 7.64ꢀ7.60 (m, 2H),
3
7
2
7
.57 (d,
H), 7.23 (dd,
, 2H), 4.69 (ABX, JAB = 15, JAX = 11, 2H, benzyl), 4.35
J
= 8, 2H), 7.38 (dt,
J
= 8, 1, 1H), 7.26 (dt,
J = 8, 2,
J
= 8, 3, 2H), 7.09 (d,
J
= 7, 2H), 7.01 (d,
J =
3
1
(
ABX, JAB = 15, JAX = 13, 2H, benzyl), 3.34ꢀ3.26 (m, 8H,
yield), which was pure according to P NMR spectroscopy.
Anal. Calcd for C H BrF P Pt: C, 47.88; H, 4.58; Found:
1
3
1
ace H), 1.2ꢀ0.2 (m, broad, 3H, BH3). C{ H} NMR
43
49
6 4
(
(
(
1
6
CDCl ): δ 147.2 (Ar, quat), 146.6 (d,
J
= 3, Ar, quat), 141.7
= 2, Ar, quat), 135.0 (Ar), 133.8 (d, = 7, Ar), 133.5
= 8, Ar), 131.3 (d, = 3, Ar), 129.4 (d, = 4, Ar, quat),
= 48, Ar, quat), 128.4 (d, = 9, Ar), 125.1 (d,
, Ar, quat), 120.3 (Ar), 120.0 (d, = 3, Ar), 114.2 (d, = 1,
= 31,
C, 48.10; H, 4.41. HRMS (m/z): calcd for C H BrP Pt
43 49 3
3
+
d,
d,
J
J
J
(M ), 932.1878; found, 932.1877 (the mass spectrum was
3
1
1
J
J
obtained for the triflate salt). P{ H} NMR (CDCl ): δ 65.6
3
28.8 (d,
J
J
J
=
(dd,
JPtꢀP = 2639, B (minor)), 64.8 (dd,
64.7 (dd, = 355, 8, JPtꢀP = 2640, A), ꢀ6.5 (dd,
JPtꢀP = 2515, B), ꢀ9.9 (dd, = 355, 18, JPtꢀP = 2515, A), ꢀ
143.2 (septet, = 712, PF6). H NMR (CDCl ): δ 7.81ꢀ7.76
(m, 2H), 7.76ꢀ7.66 (m, 8H), 7.56ꢀ7.51 (t,
7.41 (t, = 8, 2H), 7.41ꢀ7.34 (m, 3H), 7.31ꢀ7.18 (m, 7H),
7.18ꢀ7.12 (m, 3H), 7.11ꢀ7.06 (m, 3H), 7.05ꢀ7.00 (m, 2H),
6.99ꢀ6.93 (m, 3H), 6.92 (d, = 7, 1H), 6.36 (dd, = 7, 3,
1H, Ar), 6.12 (dm, JPꢀH = 373, 2H, PH), 4.62ꢀ4.50 (m, 1H,
benzyl), 4.30 (dd, = 15, 7, 1H, benzyl), 4.19ꢀ4.06 (m, 1H,
J
= 18, 8, JPtꢀP = 1601, A (major)), 65.4 (dd,
= 18, 8, JPtꢀP = 1545, B),
= 351, 18,
J = 351, 8,
J
J
J
Ar, quat), 30.3 (aceꢀCH ), 30.1 (aceꢀCH ), 29.8 (d,
benzyl CH2).
Deprotection of Ph-PyraPhos(BH ) (14) to give Ph-
PyraPhos (Ph-4) A solution of phosphineꢀborane 14 (267
mg, 0.927 mmol) in 20 mL of toluene was added to
piperazinomethyl polystyrene (1% DVB, 100ꢀ200 mesh,
Matrix Innovation, 687 mg, 2.7 mmol/g, 1.85 mmol, 2
equiv) in a 50 mL Schlenk flask. The mixture was stirred
at 60 °C under N for 2 d. The toluene was removed under
J
J
J
2
2
J
1
J
3
3
J = 7, 1H), 7.46ꢀ
J
J
J
1
7
J
2
reduced pressure; the residue was redissolved in THF and
the insoluble polystyrene resin was filtered off. Removal of
THF gave white crude product (250 mg, 98%), which
benzyl), 3.40ꢀ3.23 (m, 8 H, ace CH ), 3.17ꢀ3.06 (m, 1H,
2
CH), 3.02ꢀ2.76 (m, 6H, 5 CH + 1 benzyl CH), 2.39ꢀ2.23 (m,
2H, CH ), 2.22ꢀ1.99 (m, 5H, 1 CH + 2 CH ), 1.92ꢀ1.52 (m,
2
2
3
1
contained 6% of the corresponding phosphine oxide ( P
NMR integration). The crude product was dissolved in
CH Cl and passed through a silica plug (5 cm long) to
7H, 1 CH + 3 CH ), 1.45 (dd,
J
J
= 19, 7, 3H, CH ), 1.43 (dd,
2
3
J
= 19, 7, 3H, CH ), 1.30 (dd,
= 19, 7, 3H, CH ), 1.21ꢀ1.12
3
3
(m, 2H, CH ), 1.00 (dd,
J = 19, 7, 3H, CH ), 0.99 (dd, J =
3
2
2
2
remove the phosphine oxide 16 (see the ESI). Removal of
16, 7, 3H, CH ), 0.87 (dd, J = 17, 8, 3H, CH ), 0.83ꢀ0.70 (m,
3 3
CH Cl gave pure white solid (234 mg, 92%).
2H, CH ), 0.55 (dd, J = 17, 7, 3H, CH ), 0.52 (dd, J = 16, 7,
2 3
2
2
+
13
1
HRMS (m/z): calcd for C H P (MH) , 275.0990, found,
3H, CH3). C{ H} NMR (CDCl ): δ 151.2–150.9 (m, Ar,
1
9
16
3
2
75.0990. We could not obtain satisfactory elemental
quat), 150.4–150.0 (m, Ar, quat), 149.6ꢀ149.4 (m, Ar, quat),
analysis data for the airꢀsensitive phosphine. Anal. Calcd for
C H P: C, 83.20; H, 5.51. Found: C, 82.56; H, 5.84.
148.4 (d,
147.9 (d,
J
J
= 4, Ar, quat), 148.3 (Ar, quat), 148.1 (Ar, quat),
= 4, Ar, quat), 142.2 (d, = 2, Ar, quat), 142.1
J
1
9
15
3
1
1
1
P{ H} NMR (CDCl ): δ ꢀ5.6. H NMR (CDCl ): δ 7.64
(d,
138.0 (broad, Ar, quat), 136.9 (Ar), 135.5 (Ar), 135.0 (Ar),
134.6 (d, = 2, Ar), 134.5 (d, = 2, Ar), 134.2 (d, = 7,
Ar), 134.0 (d, = 7, Ar), 134.1–133.5 (m, Ar), 133.3–132.9
(m, Ar), 132.6 (d, = 2, Ar), 131.8 (d, = 2, Ar), 130.4 (d,
= 5, Ar), 129.4 (d, = 10, Ar), 129.2 (d, = 10, Ar), 128.9
(d, = 6, Ar), 128.1 (d, = 3, Ar, quat), 127.6 (Ar, quat),
127.5 (Ar, quat), 125.8–125.3 (m, Ar, quat), 124.9 (Ar),
124.8 (Ar), 121.5 (Ar), 121.1 (Ar), 120.4 (d, = 4, Ar),
119.8 (d, = 3, Ar), 113.1 (d, = 2, ArꢀBr, quat, A), 112.9
(d, = 2, ArꢀBr, quat, B), 44.02 (d, = 34, JPtꢀC = 40, CH),
44.00 (d, = 35, JPtꢀC = 40, CH), 42.3 (d, = 30, JPtꢀC = 15,
CH), 42.2 (d, = 30, JPtꢀC = 17, CH), 37.6 (d, = 5, CH2),
37.4 (d, = 30, CH), 37.2 (d,
J = 2, Ar, quat), 140.9–139.6 (m, Ar, quat), 139.9 (Ar),
3
3
(
dd, JPꢀH = 3, JHꢀH = 7, 1H), 7.36ꢀ7.31 (m, 2H), 7.31ꢀ7.25 (m,
H), 7.25ꢀ7.20 (m, 3H), 3.84 (ABX, JAB = 17, JAX = 23, 1H,
benzyl), 3.50ꢀ3.44 (m, 4H, ace H), 3.41 (ABX, JAB = 17, JAX
3
J
J
J
J
1
3
1
=
5, 1H, benzyl).
quat), 142.7 (Ar, quat), 141.6 (d,
= 5, Ar, quat), 139.1 (d, = 2, Ar, quat), 137.9 (d,
Ar, quat), 137.6 (d, = 13, Ar, quat), 131.8 (d, = 19, Ar),
29.1 (d, = 19, Ar), 128.8 (Ar), 128.6 (d, = 6, Ar), 124.6
= 1, Ar), 121.0 (d, = 5, Ar), 120.6 (d, = 1, Ar), 35.8
= 16, benzyl CH ), 31.6 (aceꢀCH ), 31.2 (aceꢀCH ).
C{ H} NMR (CDCl ): δ 145.4 (Ar,
J
J
J
3
J
= 22, Ar, quat), 139.8 (d,
= 5,
J
J
J
J
J
J
J
J
J
1
J
J
J
(
(
[
d,
d,
J
J
J
J
J
J
J
J
2
2
2
Pt((R,R)-Me-DuPhos)(Ph)(PHPh(CH Ar))][PF ] (17)
A
J
J
2
6
solution of secondary phosphine Ph-11 (50 mg, 0.14 mmol)
J
J
in 1 mL of THF was added to a solution of NH PF (23 mg,
J
J
= 5, CH ), 36.80ꢀ36.59 (m,
4
6
2
0
.14 mmol, 1 equiv) in 1 mL of THF. To this mixture, a
overlapping, 4 CH ), 36.5 (d,
J
= 30, CH), 35.59ꢀ35.44 (m,
2
solution of Pt((R,R)ꢀMeꢀDuphos)(Ph)(Cl) (87 mg, 0.14
overlapping, 2 CH ), 33.3 (d,
J
= 32, JPtꢀC = 33, CH), 32.9
2
mmol, 1 equiv) in 1 mL of THF was added; a white
(d,
J
= 33, JPtꢀC = 35, CH), 30.4 (aceꢀCH ), 30.3 (aceꢀCH ),
2
2
precipitate (NH Cl) formed immediately. Progress of the
30.18 (aceꢀCH ), 30.17 (aceꢀCH ), 29.7 (dd,
J
= 30, 4, Pꢀ
4
2
2
1
0 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012

Page 11 of 15
Journal Name
Dalton Transactions
View Article Online
ART20ICLE
DOI: 10.1039/C5DT005 E
CH ), 29.3 (d,
J
= 31, JPtꢀC = 31, PꢀCH ), 17.5 (d,
J
= 7, JPtꢀC
3H, CH ), 1.01 (dd,
J
J
= 16, 7, 3H, CH ), 0.92 (dd,
J
J
= 20, 7,
= 11, 3,
2
2
3
3
=
23, CH ), 17.0 (d,
J
= 8, JPtꢀC = 22, CH ), 15.9 (d, = 5,
J
3H, CH ), 0.91 (dd,
= 17, 7, 3H, CH ), 0.70 (tq,
3
3
3
3
1
3
1
JPtꢀC = 30, CH ), 15.8 (d,
J
= 5, JPtꢀC = 30, CH ), 14.7 (d,
J
=
1H, CH ), 0.28 (dq,
J
J
= 13, 6, 1H, CH2). C{ H} NMR
= 15, 8, Ar, quat), 149.5 (d, = 2,
= 15, 8, Ar, quat), 144.0 (Ar, quat),
142.9ꢀ141.9 (m, Ar, quat), 140.6ꢀ140.3 (m, Ar), 140.2ꢀ139.9
(m, Ar, quat), 139.7 (d, = 4, Ar, quat), 138.8 (d, = 8, Ar,
quat), 138.0 (dd, = 16, 3, Ar, quat), 137.2 (Ar), 133.9 (dd,
3
3
2
2
, CH ), 14.5 (d,
J
= 2, CH ), 14.3 (d,
J
= 2, CH ), 13.8 (d,
J
(CDCl ): δ 150.0 (dd,
J
3
3
3
3
=
2, CH3).
Ar, quat), 149.3 (dd, J
Deprotonation of Secondary Phosphine Complex 17,
Observation of the Phosphido Intermediate Pt((R,R)-Me-
DuPhos)(Ph)(PPh(CH Ar)) (Ph-8) and its Cyclization to
J
J
J
2
Yield
[Pt((R,R)-Me-DuPhos)(Ph)(Ph-PyraPhos)][PF6]
J
= 14, 2, Ar), 133.3ꢀ133.0 (m, Ar), 132.8 (d,
J
= 5, Ar),
(
18) A solution of NaOSiMe (5.2 mg, 0.046 mmol) in 0.4
132.0 (d,
131.09 (Ar), 130.9 (d,
128.9 (d,
J
= 2, JPtꢀC = 19, Ar, quat), 131.14 (d,
= 9, Ar), 129.2 (d,
= 4, Ar), 128.3 (d, = 4, JPtꢀC = 48, Ar), 125.4 (d,
= 8, Ar), 124.4 (Ar), 121.5 (Ar), 121.3 (d, = 10, Ar), 44.4
(dd, = 34, 2, JPtꢀC = 39, CH), 41.8 (d, = 30, JPtꢀC = 18,
CH), 38.8 (d, = 28, JPtꢀC = 18, CH), 37.1 (JPtꢀC = 20, CH2),
36.6 (d, = 2, JPtꢀC = 31, CH ), 35.5ꢀ35.3 (m, overlapping, 2
CH ), 33.8 (d, J = 41, JPtꢀC = 40, CH benzyl), 33.2 (d, J =
2
J = 7, Ar),
J = 11, Ar),
3
mL of THF was added to a solution of cation 17 (50 mg,
.046 mmol) in 1 mL of THF, to give a bright yellow
J
0
J
J
3
1
solution. The P NMR spectrum confirmed the formation
of the two diastereomers of complex Ph-8
3
J
J
.
J
J
1
1
P{ H} NMR (THF): δ 60.1 (d,
9.4 (d,
JPtꢀP = 1700, B), ꢀ30.1 (d,
96, JPtꢀP = 852, B), ꢀ144.7 (septet,
J
= 107, JPtꢀP = 1753, A),
J
5
(
=
J
= 100, JPtꢀP = 1761, B), 56.7 (JPtꢀP = 1738, A), 55.6
= 119, JPtꢀP = 881, A), ꢀ56.6 (d,
= 711, PF ). The
J
2
J
J
2
J
35, JPtꢀC = 35, CH), 31.8 (aceꢀCH ), 31.2 (aceꢀCH ), 17.9 (d,
6
2
2
diastereomer ratio was about 2:1 (A/B), and all the signals
were broad.
J
(d,
= 10, JPtꢀC = 21, CH ), 15.7 (d,
J
= 6, JPtꢀC = 28, CH ), 14.6
3
3
J
= 3, CH ), 14.2 (d,
J
= 2, CH3).
-Ph-PyraPhos)][PF ] (18b’)
3
The mixture was stirred at room temperature and white
precipitate slowly formed. After stirring for 25 h, 44% of the
[Pt((S,S)-Me-DuPhos)(Ph)(
R
6
3
1
1
P{ H} NMR (CDCl ): δ 68.6 (dd,
J
= 16, 7, JPtꢀP = 1685),
= 367, 7, JPtꢀP = 2612), 23.5 (dd, = 367, 16, JPtꢀP
= 712, PF ). H NMR (CDCl ): δ
3
3
1
phosphido complex cyclized to form 18 ( P NMR
63.5 (dd,
= 2578), ꢀ143.2 (septet,
7.92 (dd, = 7, 7, 1H), 7.80ꢀ7.75 (m, 1H), 7.75ꢀ7.69 (m,
2H), 7.45ꢀ7.41 (m, 1H), 7.41ꢀ7.37 (m, 4H), 7.31 (JPtꢀH = 16,
2H), 7.26ꢀ7.23 (m, 3H), 6.95 (t, = 7, 1H), 6.69 (t, = 7,
1H), 6.60 (dd, = 7, 7, JPtꢀH = 41, 1H), 6.46 (dd, = 7, 7,
1H), 4.05ꢀ3.94 (m, 2H, benzyl), 3.52ꢀ3.43 (m, 4 H, ace
CH ), 3.09ꢀ3.02 (m, 1H, CH), 2.98ꢀ2.87 (m, 2H, CH), 2.83ꢀ
2.75 (m, 1H, CH), 2.48ꢀ2.37 (m, 2H, CH ), 2.14ꢀ2.00 (m,
J
J
1
integration). The reaction was done in 3 d and the solution
J
6
3
3
1
became colorless. The P NMR spectrum showed a 15:1
mixture of 18 and PhꢀPyraPhos (Ph-4), plus Pt((R,R)ꢀMeꢀ
DuPhos)(Ph)(Br) (19). A solution of NH PF (7.5 mg, 1
J
J
J
4
6
equiv) in 0.5 mL of THF was added to remove bromide and
convert this mixture to 18. The THF was removed under
vacuum and the solid residue was dissolved in 15 mL of
CH Cl . The solution was washed with water. After drying
J
J
2
2
2
2
with MgSO , removal of solvent gave 11 mg (24% yield) of
2H, CH ), 1.98ꢀ1.87 (m, 1H, CH ), 1.64 (dq,
J
J
J
J
= 13, 5, 1H,
= 16, 7, 3H,
= 19, 7, 3H,
= 13, 4, 1H,
4
2
2
white solid as a mixture of two diastereomers (2:1 ratio).
See the ESI for more information on this reaction under
different conditions.
Evaporation of a THF solution gave crystals of the major
diastereomer 18a, which coꢀcrystallized with THF; it
CH ), 1.24 (dd,
J
= 19, 7, 3H, CH ), 1.17 (dd,
2
3
CH ), 1.15 (1H, CH , overlapped), 1.12 (dd,
3
2
CH ), 0.90 (dd,
J
= 16, 7, 3H, CH ), 0.60 (tq,
3
3
1
3
1
CH2). C{ H} NMR (CDCl ): δ 149.8 (d,
J
= 2, Ar, quat),
144.0 (Ar, quat), 140.2ꢀ139.9 (m, Ar), 138.8 (Ar, quat),
138.7 (Ar, quat), 138.6 (Ar, quat), 137.0 (Ar), 134.1 (d,
15, Ar), 133.4 (d, = 3, Ar), 133.3ꢀ133.0 (m, Ar), 132.9 (d,
= 6, Ar), 132.5 (d, = 8, Ar), 132.1 (JPtꢀC = 17, Ar), 132.0
JPtꢀC = 16, Ar), 131.7 (d, = 2, Ar), 129.9 (d, = 6, JPtꢀC
44, Ar), 129.4 (d, = 11, Ar), 128.0 (d, = 6, Ar), 125.4 (d,
= 7, Ar), 124.8 (Ar), 121.6 (Ar), 121.5 (Ar), 44.0 (d,
36, CH), 42.6 (d, = 29, JPtꢀC = 16, CH), 39.5 (d, = 27, JPtꢀ
= 19, CH), 39.2ꢀ38.7 (m, CH benzyl), 37.6 (JPtꢀC = 18,
3
contained
enantiomer of the minor diastereomer, [Pt((S,S)ꢀMeꢀ
DuPhos)(Ph)( ꢀPhꢀPyraPhos)][PF6] 18b’), for which
characterization data is included below.
Pt((R,R)-Me-DuPhos)(Ph)( -Ph-PyraPhos)][PF6] (18a)
Anal. Calcd for C H F P Pt·C H O: C, 52.76; H, 5.28;
R
ꢀPhꢀPyraPhos. See the ESI for synthesis of the
J =
J
R
(
J
(
J
J
J
=
[
R
J
J
J
J =
4
3
48
6
4
4
8
Found: C, 52.77; H, 5.29. HRMS (m/z): calcd for
J
J
+
31
1
C H P Pt (M ), 852.2617; found, 852.2607.
P{ H}
= 15, 8, JPtꢀP = 1695), 63.1 (dd,
= 368, 8, JPtꢀP = 2607), 23.2 (dd, = 368, 15, JPtꢀP = 2561),
= 713, PF6). H NMR (CDCl ): δ 7.83 (t,
4
3
48
3
C
2
NMR (CDCl ): δ 68.3 (dd,
J
CH ), 36.6 (JPtꢀC = 27, CH ), 36.0 (d, J = 4, CH ), 35.2 (d, J
2 2 2
3
J
J
= 5, CH ), 32.7 (d,
J
= 32, JPtꢀC = 32, CH), 31.9 (aceꢀCH2),
2
1
ꢀ
143.2 (septet,
J
J
31.2 (aceꢀCH ), 18.0 (d, = 9, CH ), 15.5 (d, = 5, JPtꢀC =
J
J
3
2
3
=
7, 1H), 7.75ꢀ7.67 (m, 3H), 7.55 (t,
= 7, JPtꢀH = 34, 1H), 7.03ꢀ6.97 (m, 1H),
= 7, JPtꢀH = 39, 1H), 6.81ꢀ6.72 (m, 2H), 4.24 (AB,
J
= 7, 1H), 7.44ꢀ7.27
29, CH ), 14.28 (CH ), 14.27 (CH ).
3 3 3
(
m, 8H), 7.06 (t,
J
Reaction of Pt-Phosphido Complex Ph-8 with Silver
Triflate Gave Mixture of Products, Including
6
.95 (t,
J
a
JAB = 18, JPtꢀH = 27, 1H, benzyl), 3.74 (ABX, JAB = 18, JAX
9, JPtꢀH = 13, 1H, benzyl), 3.57ꢀ3.36 (m, 4 H, ace CH2),
.19ꢀ3.08 (m, 1H, CH), 2.90ꢀ2.74 (m, 3H, CH), 2.28ꢀ2.16
Cyclometalated Cation 21 and Ph-PyraPhos Complex 18
A solution of cation 17 (30 mg, 0.028 mmol) in 0.3 mL of
=
3
THF was treated with a solution of NaOSiMe (4 mg, 0.04
3
(
1
m, 1H, CH ), 2.07ꢀ1.92 (m, 3H, CH ), 1.87 (dq,
J
J
= 13, 5,
= 19, 7,
mmol, 1.2 equiv) in 0.4 mL of THF to give a bright yellow
2
2
H, CH ), 1.64 (dq,
J
= 13, 5, 1H, CH ), 1.40 (dd,
solution of Ptꢀphosphido complex Ph-8
.
A solution of
2
2
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 11

Dalton Transactions
Page 12 of 15
View Article Online
ARTICLE
DOI: 10.1039/C5DT00520E
Journal Name
AgOTf (8 mg, 0.03 mmol, 1 equiv) in 0.4 mL of THF was
added dropwise to the mixture, which immediately became
dark. Within one minute, the mixture turned completely
black and a precipitate formed. The mixture was either
transferred into a NMR tube directly (A), or filtered through
a Celite plug, which was washed with 0.5 mL of THF. The
combined filtrates were transferred into a NMR tube (B). In
both cases, the reaction was monitored by P NMR
spectroscopy, which showed that Ph-8 had been consumed
within minutes to yield intermediates with characteristic
very broad signals near 0 ppm, as well as DuPhos
resonances. These intermediates (see the ESI) decomposed
over a few days to yield a mixture including cyclometalated
Anal. Calcd for C H F P Pt: C, 51.76; H, 4.85; Found: C,
43 48 6 4
+
51.36; H, 4.57. HRMS (m/z): calcd for C H P Pt (M ),
4
3
48 3
3
1
1
852.2617; found, 852.2629. P{ H} NMR (CDCl ): δ 66.9
3
(dd,
1762), 7.9 (dd,
J
= 356, 8, JPtꢀP = 2672), 62.8 (dd,
= 356, 13, JPtꢀP = 2566), ꢀ144.3 (septet,
712, PF6). H NMR (CDCl ): δ 7.80 (dd,
J
= 13, 8, JPtꢀP
=
=
J
J
1
J
= 7, 7, 1H), 7.74
= 7, 7, 1H), 7.69ꢀ7.64 (m, 2H), 7.58 (dd, = 7, 7, JPtꢀH
= 42, 1H), 7.56ꢀ7.53 (m, 2H), 7.52ꢀ7.48 (m, 1H), 7.48ꢀ7.40
3
(dd,
J
J
3
1
(br, m, 2H), 7.30ꢀ7.25 (m, 3H), 7.14 (t,
= 7, 1H), 7.04ꢀ6.99 (m, 3H), 4.48 (dd,
J
J
= 7, 1H), 7.10 (d,
= 16, 7, JPtꢀH = 30,
J
1H, benzyl CH ), 3.73 (ddd,
J = 16, 15, 4, JPtꢀH = 68, 1H,
2
benzyl CH ), 3.57ꢀ3.46 (m, 1H, CH), 3.28ꢀ3.08 (m, 4H, ace
2
CH ), 2.90ꢀ2.80 (m, 1H, CH), 2.68ꢀ2.56 (m, 1H, CH), 2.25ꢀ
2
cation 21 (major product), PhꢀPyraPhos complex 18, and an
2.10 (m, 2H, CH ), 1.97ꢀ1.80 (m, 2H, CH ), 1.73ꢀ1.62 (m,
2
2
+
unidentified [Pt(DuPhos)(phosphine)(X)]
complex 22
2H, CH ), 1.57ꢀ1.47 (m, 1H, CH, overlapped), 1.51 (dd,
J
J
=
=
2
3
1
1
(
P{ H} NMR (CDCl ):
δ
76.7 (d, J = 360, JPtꢀP = 2298),
19, 7, 3H, CH ), 1.03 (dd, J = 16, 7, 3H, CH ), 0.86 (dd,
3 3
3
6
2
7.8 (d, J = 13, JPtꢀP = 3338), 14.1 (dd, J = 360, 13, JPtꢀP
382)), in which the PtꢀP coupling constant of 3338 Hz
=
20, 7, 3H, CH ), 0.78ꢀ0.70 (m, 1H, CH ), 0.59 (dd,
J
= 16,
3
2
1
3
1
7, 3H, CH ), 0.44 (qm,
J = 13, 1H, CH2). C{ H} NMR
3
suggested the Pt–C bond had been broken. When the
reaction mixture was filtered after addition of AgOTf
(CDCl ): δ 146.9 (Ar, quat), 143.5 (Ar, quat), 141.9 (ddd, J
3
= 42, 30, 5, Ar, quat), 140.1 (d,
J
= 5, Ar, quat), 140.0 (ddd,
= 44, 31, 3, Ar, quat), 138.4 (ddd, = 89, 18, 5, Ar, quat),
= 9, Ar), 135.0ꢀ134.5 (broad, Ar), 134.7
= 5, Ar, quat, overlapped), 134.4 (dd, = 12,
= 13, 1, Ar), 133.1 (dt, = 13, 2,
= 6, 2, Ar), 132.5 (d, = 5, Ar), 131.8 (d,
= 2, Ar), 131.5 (d, = 2, Ar), 129.4 (d, = 10, Ar), 129.2 (d,
= 10, Ar), 128.3 (d, = 12, Ar), 128.0 (d, = 4, Ar, quat),
126.8ꢀ126.6 (m, Ar, quat), 120.1 (d, = 6, JPtꢀC = 49, Ar),
118.4 (Ar), 42.3 (d, = 35, JPtꢀC = 51, CH), 41.6 (d, = 31,
JPtꢀC = 19, CH), 36.2 (d, = 3, JPtꢀC = 30, CH ), 36.1 (JPtꢀC
(
procedure B), less of 22 was formed.
J
J
Independent Synthesis of Cation 21 by Oxidative
Addition of Phosphine 12 to Pt(0) A solution of phosphine
136.7 (d,
(apparent t,
J
J
J
1
2
(43 mg, 0.10 mmol) in 2 mL of THF was added to a light
brown solution of crude Pt((R,R)ꢀMeꢀDuphos)(trans
stilbene) (68 mg, 0.10 mmol, 1 equiv) in 2 mL of THF. The
4, Ar, quat), 133.3 (dd,
Ar), 132.6 (dd,
J
J
ꢀ
J
J
J
J
J
3
1
mixture was stirred at room temperature for 6 h. The
P
J
J
J
NMR spectrum showed full conversion of the Pt complex to
product 21, with about 10% of unreacted 12. After addition
of approximately 20 mg of extra crude Pt((R,R)ꢀMeꢀ
Duphos)(transꢀstilbene) in multiple portions, all the
phosphine was consumed.
J
J
J
J
=
2
20, CH ), 36.0 (d,
J
= 4, CH ), 35.3 (d,
J
= 4, CH ), 34.0 (d,
2
2
2
J
= 27, JPtꢀC = 16, CH), 30.0 (aceꢀCH ), 29.8 (aceꢀCH ), 29.6
2
2
NH PF (18 mg, 0.11 mmol, 1.1 equiv) was added to the
(d,
J
= 32, CH), 29.4 (d,
J
= 39, benzyl CH ), 19.5 (d,
J
= 9,
JPtꢀC = 27, CH ), 17.4 (d, J = 6, JPtꢀC = 42, CH ), 13.8 (CH ),
3
4
6
2
reaction mixture. A white precipitate formed immediately.
The mixture was filtered through a Celite plug to give a
clear light brown solution, which was concentrated under
vacuum and loaded onto a silica column. A mixture of ethyl
3
3
13.5 (d, J = 2, CH3).
Acknowledgements
We thank the National Science Foundation for support, and
Ken Feldman (Penn State) for details of the synthesis of acid
acetate and pentane (2:1 ratio) was used as eluent (R = 0.2
f
in 3:1 ethyl acetate/pentane). After removal of the solvent
under vacuum, the product was dissolved in CH Cl and
9
.
2
2
filtered through a Celite plug. Removal of CH Cl under
2
2
Notes and references
vacuum gave 63 mg (64% yield) of light yellow solid, which
contained less than 2% impurities, as indicated by NMR
spectra.
a
6
128 Burke Laboratory, Department of Chemistry, Dartmouth
College, Hanover, New Hampshire 03755, United States
b
Department of Chemistry, University of California, San Diego, 9500
In a similar reaction starting with 46 mg (0.11 mmol) of
phosphine 12, after the reaction was completed, 23 mg of
NH PF (0.14 mmol, 1.3 equiv) was added to the mixture
Gilman Drive, La Jolla, California 92093, United States
4
6
Electronic Supplementary Information (ESI) available: Additional
and a white precipitate formed immediately. The mixture
was filtered through a Celite plug to give a clear light brown
solution. Removal of the solvent under vacuum gave a light
brown residue, which was washed with 20 mL of ether. A
solution of the residue in 10 mL of CH Cl was washed with
experimental details (text, tables, and NMR spectra)
crystallographic data has been deposited (CCDC numbers 1047184ꢀ
047193) See DOI: 10.1039/b000000x/
.
Xꢀray
1
2
2
water (2 x 10 mL), concentrated under vacuum, loaded onto
a silica column, and eluted with 3:1 ethyl acetate/pentane.
Small analytically pure light yellow Xꢀray quality crystals
formed from the eluent in 1 h.
1
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012

Page 13 of 15
Journal Name
Dalton Transactions
View Article Online
ART20ICLE
DOI: 10.1039/C5DT005 E
1
2
. B. J. Anderson, M. A. Guinoꢀo, D. S. Glueck, J. A. Golen, A. G.
DiPasquale, L. M. LiableꢀSands and A. L. Rheingold, Org. Lett.
008, 10, 4425–4428.
11. (a) K. S. Feldman, R. F. Campbell, J. C. Saunders, C. Ahn and K.
M. Masters, J. Org. Chem., 1997, 62, 8814ꢀ8820. (b) K. S.
Feldman, personal communication, 2008.
,
2
. (a) A. Grabulosa, P-Stereogenic Ligands in Enantioselective
Catalysis, RSC, Cambridge, 2011. (b) X. Zhang, K. Huang, G.
12. (a) C. Scriban and D. S. Glueck, J. Am. Chem. Soc., 2006, 128
2788ꢀ2789. (b) C. Scriban, D. S. Glueck, J. A. Golen and A. L.
Rheingold, Organometallics 2007, 26 1788ꢀ1800.
,
Hou, B. Cao and X. Zhang, Angew. Chem. Int. Ed., 2010, 49
,
,
,
6
421–6424. (c) H. Shimizu, T. Saito and H. Kumobayashi, Adv.
(Addition/Correction: Organometallics 2007, 26, 5124).
13. D. K. Wicht, S. N. Paisner, B. M. Lew, D. S. Glueck, G. P. A.
Yap, L. M. LiableꢀSands, A. L. Rheingold, C. M. Haar and S. P.
Nolan, Organometallics, 1998, 17, 652ꢀ660.
Synth. Catal., 2003, 345, 185ꢀ189. (d) W. Tang, B. Qu, A. G.
Capacci, S. Rodriguez, X. Wei, N. Haddad, B. Narayanan, S. Ma,
N. Grinberg, N. K. Yee, D. Krishnamurthy and C. H. Senanayake,
Org. Lett., 2009, 12, 176ꢀ179.
14. P. Mastalerz, Rocznicki Chemii, 1965, 39, 33ꢀ38.
3
4
. H. Goldstein and P. Francey, Helv. Chim. Acta, 1932, 15, 1362ꢀ
15. E. P. Kyba and S. T. Liu, Inorg. Chem., 1985, 24, 1613ꢀ1616.
16. (a) M. F. Cain, R. P. Hughes, D. S. Glueck, J. A. Golen, C. E.
Moore and A. L. Rheingold, Inorg. Chem., 2010, 49, 7650–7662.
(b) M. F. Cain, S. C. Reynolds, B. J. Anderson, D. S. Glueck, J.
1
366.
. (a) R. J. Bailey, P. Card and H. Shechter, J. Am. Chem. Soc., 1983,
05, 6096ꢀ6103. (b) J. S. Kiely, L. L. Nelson and P. Boudjouk, J.
1
Org. Chem., 1977, 42, 1480ꢀ1480.
A. Golen, C. E. Moore and A. L. Rheingold, Inorg. Chim. Acta
2011, 369, 55ꢀ61.
,
5
6
. W. D. Neudorff, D. Lentz, M. Anibarro and A. D. Schluter, Chem.
Eur. J., 2003,
. (a) V. Balasubramaniyan, Chem. Rev., 1966, 66, 567ꢀ641. (b) R. H.
Mitchell, T. Fyles and L. M. Ralph, Can. J. Chem., 1977, 55
480ꢀ1497.
9
, 2745ꢀ2757.
17. S. Sayalero and M. A. Pericas, Synlett, 2006, 2585ꢀ2588.
18. C. R. Hilliard, N. Bhuvanesh, J. A. Gladysz and J. Blumel, Dalton
Trans., 2012, 41, 1742ꢀ1754.
,
1
19. (a) C. Scriban, D. K. Wicht, D. S. Glueck, L. N. Zakharov, J. A.
Golen and A. L. Rheingold, Organometallics, 2006, 25, 3370ꢀ
3378. (b) C. Scriban, D. S. Glueck, A. G. DiPasquale and A. L.
Rheingold, Organometallics, 2006, 25, 5435ꢀ5448.
7
. (a) R. L. Clough, W. J. Kung, R. E. Marsh and J. D. Roberts, J.
Org. Chem., 1976, 41, 3603ꢀ3609. (b) H. Kawai, T. Takeda, K.
Fujiwara, M. Wakeshima, Y. Hinatsu and T. Suzuki, Chem. Eur.
J., 2008, 14, 5780ꢀ5793. (c) W. Cross, G. E. Hawkes, R. T.
Kroemer, K. R. Liedl, T. Loerting, R. Nasser, R. G. Pritchard, M.
Steele, M. Watkinson and A. Whiting, J. Chem. Soc., Perkin
Trans. 2, 2001, 459ꢀ467.
20. C. Scriban, D. S. Glueck, J. A. Golen, and A. L. Rheingold,
Organometallics 2007, 26, 1788ꢀ1800. (Addition/Correction:
Organometallics 2007, 26, 5124).
21. (a) A. YahavꢀLevi, I. Goldberg, A. Vigalok and A. N.
Vedernikov, Chem. Commun., 2010, 46, 3324ꢀ3326. (b) A.
YahavꢀLevi, I. Goldberg, A. Vigalok and A. N. Vedernikov, J.
Am. Chem. Soc., 2008, 130, 724ꢀ731. (c) D. M. Crumpton and K.
I. Goldberg, J. Am. Chem. Soc., 2000, 122, 962ꢀ963. (d) K. I.
Goldberg, J. Yan and E. M. Breitung, J. Am. Chem. Soc., 1995,
117, 6889ꢀ6896. (e) K. Grice, M. Scheuermann, and K. Goldberg,
Top. Organomet. Chem., 2011, 35, 1ꢀ28.
8
9
. J. Beckmann, E. Hupf, E. Lork and S. Mebs, Inorg. Chem., 2013,
52, 11881−11888.
.
For reviews of tuning periꢀinteractions using naphthalene and
acenaphthene scaffolds, see: (a) P. Kilian, F. R. Knight and J. D.
Woollins, Coord. Chem. Rev., 2011, 255, 1387ꢀ1413. (b) P.
Kilian, F. R. Knight and J. D. Woollins, Chem. Eur. J., 2011, 17
,
2
302ꢀ2328.
1
0. Some papers have concluded that naphthalene and acenaphthene
scaffolds are equivalent. (a) See footnote 5 in ref 9b: “Note that
the ethylene bridge in acenaphthene has essentially no effect on
the periꢀregion geometry or electronic properties.” (b) P.
Wawrzyniak, A. M. Z. Slawin, A. L. Fuller, J. D. Woollins and P.
Kilian, Dalton Trans., 2009, 7883ꢀ7884. See footnote 10: “The
22. D. K. Wicht, M. A. Zhuravel, R. V. Gregush, D. S. Glueck, I. A.
Guzei, L. M. LiableꢀSands and A. L. Rheingold,
Organometallics, 1998, 17, 1412ꢀ1419.
23. A. Casitas and X. Ribas, Chem. Sci., 2013, 4, 2301ꢀ2318.
24. A. B. Pangborn, M. A. Giardello, R. H. Grubbs, R. K. Rosen and
F. J. Timmers, Organometallics, 1996, 15, 1518ꢀ1520.
25. R. L. Letsinger, J. A. Gilpin and W. J. Vullo, J. Org. Chem., 1962,
27, 672ꢀ674.
presence of an extra CH
2 2
CH group of acenaphthene has no
electronic or steric effect on the reactions described in this paper.”
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 13

Dalton Transactions
Page 14 of 15
View Article Online
ARTICLE
DOI: 10.1039/C5DT00520E
Journal Name
2
2
6. T. J. Brunker, N. F. Blank, J. R. Moncarz, C. Scriban, B. J.
Anderson, D. S. Glueck, L. N. Zakharov, J. A. Golen, R. D.
Sommer, C. D. Incarvito and A. L. Rheingold, Organometallics
005, 24, 2730ꢀ2746.
7. H. C. Clark and C. R. Jablonski, Inorg. Chem., 1975, 14, 1518ꢀ
526.
,
2
1
1
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2012

Page 15 of 15
Dalton Transactions
View Article Online
DOI: 10.1039/C5DT00520E
Synthesis of a Phosphapyracene via Metal-Mediated
Cyclization: Structural and Reactivity Effects of
Acenaphthene Precursors
a
a
a
b
Ge Wang, Marites A. Guino-o, David S. Glueck, * James A. Golen, Christopher J. A.
b
b
Daley, and Arnold L. Rheingold
Graphical and text abstract
Cl
Br
P
Ph
PH Ph
2
2
NaOSiMe3
AcePhos
PyraPhos
Pt catalyst
FAST
Cl
Br
P
Ph
PH Ph
2
2
NaOSiMe3
Pt catalyst
SLOW
A small structural change (naphthalene to acenaphthene) had large effects on reactivity,
slowing Pt-mediated phosphination/cyclization; the new heterocycle PyraPhos was
prepared with a simple Cu catalyst.