Efficient synthesis of 2-methyl derivatives of 1,1′-bi(2-naphthol) and 1,1′-bi(2-phenols)

Article abstract of DOI:10.1002/ejoc.200600962

Reaction of 1,1′-binaphthol and structurally related 1,1′-biphenols with sulfonylating reagents [RSO₂Cl; R = 4-Tol, Ph] leads to clean, ultraselective monoderivatisation, shown crystallographically in one case (2-OH-2′-OTs-1,1′-binaphthyl). Reaction of the remaining 2-hydroxy function with either Tf₂O or NfF [Nf = nonaflate, CF₃(CF₂)₃SO₂-] affords the protected/activated cores (2-R¹O-2′-R ²O-1,1′-biaryl) [R¹,R² pairs = Tf,Ts (X-ray); Tf,SO₂Ph; Nf,Ts (on 1,1′-binaphthyl core); Tf,Ts; Nf,Ts (on 1,1′-biphenyl core); Tf,Ts; Nf,Ts (on 3,3′,5,5′- tetramethyl-1,1′-biphenyl core)]. Reaction of the Tf,Ts species with either MeMgBr/NiCl₂(dppe) (for the 1,1′-binaphthyl) or (AlMe₃)₂(DABCO)/Pd₂(dba)₃ (for the 1,1′-biphenyl) affords 2-OH-2′-Me-1,1′-biaryl units on subsequent hydrolysis (crystallographically characterised in the binaphthyl case). The latter methyl/hydroxy compounds are doubly deprotonated by either nBuLi/TMEDA or nBuLi/tBuOK to afford dianions that react cleanly with Cl ₂SiPh₂ (two X-ray structures). The equivalent reaction of the 2-OH-2′-Me-1,1′-binaphthyl with Ph(O)Cl₂ is less clean due to the absence of a strong Thorpe-Ingold effect. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.

Full text of DOI:10.1002/ejoc.200600962

FULL PAPER
DOI: 10.1002/ejoc.200600962
Efficient Synthesis of 2-Methyl Derivatives of 1,1Ј-Bi(2-naphthol) and
1,1Ј-Bi(2-phenols)
Maurizio Solinas,[a] Rebecca E. Meadows,[a] Claire Wilson,[a] Alexander J. Blake,[a] and
Simon Woodward*[a]
Keywords: Axial chirality / Biaryl compounds / Binaphthyl compounds / Silicon / Phosphorus
Reaction of 1,1Ј-binaphthol and structurally related 1,1Ј-bi-
phenols with sulfonylating reagents [RSO2Cl; R = 4-Tol, Ph]
leads to clean, ultraselective monoderivatisation, shown crys-
tallographically in one case (2-OH–2Ј-OTs–1,1Ј-binaphthyl).
Reaction of the remaining 2-hydroxy function with either
Tf2O or NfF [Nf = nonaflate, CF3(CF2)3SO2-] affords the pro-
tected/activated cores (2-R1O–2Ј-R2O–1,1Ј-biaryl) [R1,R2
pairs = Tf,Ts (X-ray); Tf,SO2Ph; Nf,Ts (on 1,1Ј-binaphthyl
core); Tf,Ts; Nf,Ts (on 1,1Ј-biphenyl core); Tf,Ts; Nf,Ts (on
3,3Ј,5,5Ј-tetramethyl-1,1Ј-biphenyl core)]. Reaction of the
Tf,Ts species with either MeMgBr/NiCl2(dppe) (for the 1,1Ј-
binaphthyl) or (AlMe3)2(DABCO)/Pd2(dba)3 (for the 1,1Ј-bi-
phenyl) affords 2-OH–2Ј-Me–1,1Ј-biaryl units on subsequent
hydrolysis (crystallographically characterised in the binaph-
thyl case). The latter methyl/hydroxy compounds are doubly
deprotonated by either nBuLi/TMEDA or nBuLi/tBuOK to af-
ford dianions that react cleanly with Cl2SiPh2 (two X-ray
structures). The equivalent reaction of the 2-OH–2Ј-Me–1,1Ј-
binaphthyl with Ph(O)Cl2 is less clean due to the absence of
a strong Thorpe–Ingold effect.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2007)
strategy. While this has been achieved in the 6-,[12] 3-[13] and
2-positions[14] for C2 symmetric 1,1Ј-binaphthyl com-
pounds, clean very highly selective (Ͼ98%) monofunction-
alisation of the 2-position of 1 is often problematic. We set
about to find a solution to this problem and to extend these
ideas to suitable 1,1Ј-biphenol compounds leading to a fam-
ily of interesting dissymmetric 1,1Ј-biaryl compounds.
Introduction
1,1Ј-Binaphthyl and 1,1Ј-biphenyl units are the subject of
growing interest due to a number of useful structural cores
that find application in materials,[1] natural products,[2]
polymers synthesis[1] and chiral stationary phases for chro-
matographic applications.[3] For example, biphenyl units are
present in important antibiotics such as biphenomycin and
vancomycin[4] and in potent antitumor agents such as ellagi-
tannins.[5] Polyhydroxylated derivatives have also found use
as antioxidants in food preservatives.[6] Most commonly,
1,1Ј-binaphthyl and biphenyl scaffolds have found use in the
production of highly effective chiral ligands, especially
those with C2 symmetry,[7] of which BINAP[8] is probably
the best known. More recently, 1,1Ј-bi(2-naphthol) 1 has
been used for hybrid materials in the preparation of sup-
ported catalysts in heterogeneous asymmetric catalysis.[9]
Despite these large number of applications, modular prepa-
ration of C1 1,1Ј-binaphthyl and biphenyl units is often hin-
dered by the need to prepare appropriate aryl coupling
partners, followed (in chiral cases) by resolution when the
direct stereoselective synthesis is not possible.[10] Such spe-
cies could have numerous uses e.g. in ligand preparation or
as precursors to chiral acids.[11] Given the ready availability
of the parent enantiopure 1,1Ј-bi(2-naphthol) (1b), regiose-
lective functionalisation of the ring positions is an attractive
Results and Discussions
We are interested in the synthesis of C1-symmetric li-
gands prepared from 1,1Ј-bi(2-naphthol) (1) by selective
functionalisation of just one of the 2-hydroxy groups.[15] To
maximise the synthetic utility of any new approach to such
species, it is important to realise a preparation that is: (i)
technically simple, (ii) succinct and not reliant on extensive
chromatographic purification and (iii) can be extended
readily to the 1,1Ј-biphenol analogues. There are already a
number of literature monoprotections of 1,1Ј-bi(2-naph-
thol) (1), of which methylation and triflation are the most
common.[14b,16] While quite selective, none of these reac-
tions are completely monoselective and chromatographic
separation of unreacted starting material and bis-alkylated
products is subsequently required. Previously, we had
shown that carbamoyl chlorides and related acid chlorides
reacted with 1,1Ј-bi(2-naphthol) (1) to give monoacylated
binol derivatives.[15] In this case, careful control of the reac-
tion conditions was often required to give excellent monose-
lectivity. We had speculated that the origin of the selectivity
for the monoacylation was due to the presence of intramo-
[a] School of Chemistry, The University of Nottingham,
University Park, Nottingham, United Kingdom
Fax: +44-115-9513564
E-Mail: simon.woodward@nottingham.ac.uk
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lecular hydrogen bonds between the installed carbonyl and
the remaining hydroxy group. We expected similar factors
to operate in the reaction of 1 with tosyl chloride (4-TsCl,
4-MeC6H4SO2Cl) and other sulfonyl chlorides. We were
therefore delighted to discover that the reaction of (Rax)-
1,1Ј-bi(2-naphthol) (1) with p-toluenesulfonyl chloride is ex-
tremely selective and proceeds readily to completion even
when only 1.0 equiv. of TsCl is present. The reaction could
be readily extended to other sulfonyl chlorides and 1,1Ј-
biphenol analogues (Scheme 1). The reactions were typi-
cally complete within 8 h but could be stirred overnight
without harm. For clarity only transformations from (Rax)-
binol (1) are shown in Scheme 1. This corresponds to an
(M) axis of chirality which is used throughout this paper,
as the peculiarities of the CIP rules[17] can result in an ap-
parent stereochemical inversion upon replacement of the 2-
OH group (see later). This remarkably simple TsCl pro-
cedure does not seem to have been commonly employed
before, although there is a passing reference to a similar
observation in a more substituted case.[18] A crystallo-
graphic investigation of 2a (Figure 1) revealed the forma-
tion of an intermolecular hydrogen-bonded motif as op-
posed to the intramolecular interactions we had observed
previously in carbamate derivatives.[15] Typically, the com-
pounds 2 and 4 were highly crystalline and easily obtained
in high purity (Ͼ99%) and excellent yield (90–100%). Only
compound 4b was isolated in less than 90% recrystallised
yield (73%). However, the conversion to 4b was still essen-
tially quantitative. In fact, all of the reaction mixtures were
so clean, containing essentially single sulfonyl compounds,
that they could be used directly in one-pot procedures with-
out the need for isolation in all cases.
Figure 1. (a) Molecular structure of (P)-(Sax)-2a. Solvent molecule
and hydrogen atoms omitted for clarity. Displacement ellipsoids
drawn at 50% probability level. Selected inter atomic distances [Å]
and angles [°]: O(2)···O(3a)i (i = x – 1, y, z) 2.795(2), H(2O)···
O(3a)i 1.97, O(2)–H(2O)–O(3a)i 166, O(2)–C(2) 1.373(3), S–O(3a)
1.4359(15); (b) View showing hydrogen bonding interaction in (P)-
(Sax)-2a, forming a chain parallel to the crystallographic a axis.
(80–99%) after overnight stirring at ambient temperature.
These preparations could easily be extended to the nona-
flate [Nf = CF3(CF2)3SO2-] derivatives by use of NfF (5c/
6c–d). The selectively protected/activated 1,1Ј-binaphthyl 5
and 1,1Ј-biphenyl 6 derivatives could be obtained by a two-
step one-pot procedure without the need to isolate 2 or 4
simply by adding Tf2O at the end of the first step
(Scheme 2). This procedure is extremely simple and highly
robust: no inert atmosphere is required and normal (un-
dried) technical grade dichloromethane and NEt3 can be
used without a reduction in yields. These technically simple
preparations may be carried out on a large scale (although
we normally restricted our reactions to a 5 g upper limit).
The only complication to arise in the one-pot process was
the need to wash the crude products with copious warm
water to completely remove the significant amounts of the
NEt3·HCl by-product that is formed on a large scale. All of
Scheme 1. Synthesis of mono-tosylated and mono-sulfonylated bi-
aryl derivatives. Reagents and conditions: (i) TsCl or PhSO2Cl
(1.01 equiv.), DMAP (15 mol-%), NEt3 (1.1 equiv.), dichlorometh-
ane, room temperature, 8 h.
The reaction of the tosylated 1,1Ј-binaphthyl species 2a– the products 5 and 6 were found to be highly crystalline
b, or any of its 1,1Ј-biphenyl analogues 4a–c, with trifluoro- negating the use of chromatographic purification. In the
methanesulfonic anhydride (Tf2O)[16b] led to the clean for- case of 5a the molecular connectivity was confirmed by a
mation of the triflate derivatives 5a–b/6a–b in high yield crystallographic study (Figure 2).
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2-Methyl Derivatives of 1,1Ј-Biaryls
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only step in the synthetic sequence to require chromatog-
raphy. While 7 is crystalline (Figure 3) its direct precipi-
tation from the crude product could not be routinely at-
tained. Nevertheless, 7 is obtained with a 60–65% isolated
yield from (M)-(Rax)-binol (1) after just two two-step, one-
pot procedures. This is a significant improvement on litera-
ture routes to this potentially useful chiral fragment. Tradi-
tionally, 7 has been prepared from A by exhaustive re-
duction of the carbonyl group (4 steps) and subsequent
BBr3-induced demethylation.[19] As A itself has to be pre-
pared either by a two-step carbonylation route[20] or a
multi-step C–C coupling reaction[20] use of 7 has, thus far,
not proved popular.
Scheme 2. One-pot synthesis of activated/protected binaphthyl and
biphenyl derivatives. Reagents and conditions: (i) TsCl or PhSO2Cl
(1.01 equiv.), DMAP (15 mol-%), NEt3 (2.2 equiv.), dichlorometh-
ane, room temperature, 8 h. (ii) Tf2O or CF3(CF2)3SO2F
(1.1 equiv.), dichloromethane, room temperature, 16 h.
Scheme 3. One-pot methylation. Reagents and conditions: (i)
either: 5a (1 equiv.), MeMgBr (3 equiv.), NiCl2(dppe) (7 mol-%),
THF 60 °C, 12 h, or: 6a (1 equiv.), (AlMe3)2(DABCO) (0.8 equiv.),
Pd2(dba)3 (3 mol-%), X-Phos (5 mol-%), THF 70 °C, 16 h; (ii)
KOH(aq.) (20 equiv.).
Figure 2. Molecular structure of (M)-(Rax)-5a. Hydrogen atoms
omitted for clarity, displacement ellipsoids drawn at 50% prob-
ability level. Selected inter atomic distances [Å] and angles [°]: S(1)–
O(1) 1.566(2), S(1Ј)–O(1Ј) 1.604(2); torsion angle C(2)–C(1)–C(1Ј)–
C(2Ј) –70.2(3).
Figure 3. Molecular structure of (M)-(Sax)-7 [derived from (Rax)-
binol]. Only one of the two crystallographically independent mole-
cules is shown, hydrogen atoms omitted for clarity; displacement
ellipsoids drawn at 50% probability level. Selected inter atomic dis-
tances [Å] and angles [°]: C(2)–C(11M) 1.504(3), C(12)–C(21M)
1.499(3), O(12)–C(2Ј) 1.368(3), O(22)–C(12Ј) 1.372(3); torsion an-
gle C(2)–C(1)–C(1Ј)–C(2Ј) –87.7(3), C(12)–C(11)–C(11Ј)–C(12Ј)
The 1,1Ј-binaphthyl compound 5a was converted to its
methyl derivative 7 via selective NiCl2(dppe)-catalysed
coupling with MeMgBr. Only the triflate group reacts un- –75.0(3).
der these homogeneous conditions. Only at extended reac-
tion times (where the reaction turns from orange to black)
were traces of the 2,2Ј-dimethylated species observed. We
suspect the subsequent tosyl-coupling is promoted by the
heterogeneous “nickel-black” that is ultimately formed in
this reaction. To minimise the number of steps required to
prepare mono methyl 7, the intermediate tosyl ester was
hydrolysed in situ with excess KOH (aq), after quenching
the excess MeMgBr with methanol (Scheme 3). A signifi-
A different approach was used for the preparation of 2-
cant excess of KOH (20 equiv.) is required to promote the OH–2Ј-Me–1,1Ј-biphenyl 8 involving the use of palladium-
hydrolysis as the by-product magnesium salts sequester sig- catalysed alkylation. While the coupling with the alkyl
nificant amounts of the hydroxide, however, the reaction Grignard for substrate 5a consistently gave 60–65% yield,
again proceeds cleanly. One-pot preparation of 7 was the and Ͻ3% of the 2,2Ј-dimethyl-1,1Ј-binaphthyl by-product,
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the equivalent performance in the 1,1Ј-biphenyl series was within 3 h with 2.5 equiv. of nBuLi/tBuOK, however, tem-
inferior. Optimal preparation of the substrate 8 was at- peratures of –40 °C or below are required to avoid unde-
tained by palladium-catalysed C–OTf coupling with sired quenching of the reaction mixture by the solvent (nor-
(AlMe3)2(DABCO) in the presence of a monophosphane mally Et2O). Using method A, it was safe to perform the
ligand from the X-Phos[21] family (85%) under conditions lithiation in Et2O at 0 °C, although attempts to increase the
recently disclosed by us.[22] Interestingly, the palladium-cat- rate of reaction by carrying it out at ambient temperature
alysed coupling of 5a and (AlMe3)2(DABCO) did not give led to a less clean reaction due to minor aryl C–H lithiation.
high yields. Even for prolonged reaction times, the coupling Method A was generally preferred for further functionali-
product was obtained in Ͻ25% yield. We believe that the sation of 2-OH-2Ј-Me-1,1Ј-binaphthyl 7 and 1,1Ј-biphenyl
increased steric hindrance in substrate 5a is responsible for 8 due to the absence of additional tert-butoxide-derived by-
this poor performance. In the case of 7 the required connec- products in the reaction mixture.
tivity could be demonstrated crystallography (Figure 3). Fi-
The dilithium species attained from 7–8 contain two an-
nally, optical rotation data showed that the M chirality of ionic sites that may be expected to have quite different reac-
–
the (Rax)-1,1Ј-bi(2-naphthol) (1) is retained throughout its tivities. The benzylic (CH2 ) anionic moiety is expected to
transformation into (M)-(Sax)-7 (The change in the axial not only be more basic, but also more nucleophilic than its
stereochemistry descriptor is purely a CIP artefact).
hydroxylic counterpart. For this reason, in order to avoid
We believed that the proximity of the 2-OH function in undesired mixed alkylation products, initial reactions of the
7 would allow for a directed and selective lithiation of the dilithium salts of 7 and 8 were carried out with dichlorodi-
2-methyl group. This goal could be realised through a phenylsilane. The formation of the desired chelate com-
short study of the required lithiation conditions using pound is expected to be favoured not only by the formation
either nBuLi/TMEDA (method A) or nBuLi/KOtBu of a strong Si–O bond (ca. 120 kcalmol–1) but by the pres-
(method B).[23] Under the optimised conditions, 7 was con- ence of a large Thorpe–Ingold effect[24] engendered by the
verted into its insoluble dark red dilithium salt using large SiPh2 fragment, favouring closure of the 7-ring che-
2.5 equiv. of nBuLi in the presence of TMEDA as a solu- late. We were delighted to discover that the reaction of the
tion in Et2O at 0 °C for 24 h. A similar procedure carried dilithium salts of both 7 and 8 led to clean formation of 9
out on substrate 8 led to an equally insoluble bright yellow and 10 respectively in good yields (Scheme 4).
1,1Ј-biphenyl-derived dianion. D2O quenching of the highly
moisture-sensitive dianion of 7 provided evidence that
Ͼ90% dilithiation had occurred (Ar–CH2D 1:1:1 triplet at
δ = 2.17 ppm, JHD = 2.2 Hz). Figure 4 shows the extent of
deuterium incorporation in 7 by lithiation under method A
conditions (nBuLi/TMEDA,1:1, see experimental for de-
tails) after 3 and 24 h reaction time. An alternative route
leading to the dilithiated compound was envisaged by using
Scheme 4. Synthesis of silane derivatives 9-10. Reagents and condi-
tions: (i): 7 or 8 (1 equiv.), nBuLi (3 equiv.), TMEDA (3 equiv.),
Et2O, 0 °C, 24 h. (ii) Cl2SiPh2, –60 °C for 3 h followed by warming
to 0 °C (2 h).
a modification of Schlosser’s “super-base” method (nBuLi/
tBuOK, 1:1, method B). In this case much shorter reaction
times are required (3 h compared with Ͼ20 h for method
A). In the case of the super-base, 95% lithiation is obtained
Compounds 9 and 10 are both highly crystalline and
were obtained in 55–60% isolated yield as colourless rods.
Crystallographic investigation of 9–10 revealed very similar
structures (Figure 5–Figure 6).
The importance of using bis-electrophiles deploying a
large steric (i.e. Thorpe–Ingold) effect to promote closure
of the chelate is reinforced by the reaction of the dilithio
species derived from 7 with phenylphosphonic dichloride.
After 7 had been doubly deprotonated by 3 equiv. of nBuLi/
TMEDA, successive quenching with Cl2P(O)Ph afforded
the formation of a single diastereomer of the expected phos-
phorus(V) compound 11a (Scheme 5). Compound 11a is
stable to hydrolysis and easily isolated by column
chromatography. The absolute stereochemistry of all ele-
ments of chirality in the molecule was assigned using crys-
tallographic analysis of a sample derived from (Sax)-binol
1. The favoured diastereoisomer is (P)-(Sax,RP)-11a with an
R configuration at the phosphorus atom (Figure 7). Al-
though essentially complete diastereoselectivity is seen, the
yield of this compound is poor (up to 17%). Inspection of
Figure 4. Deuterium incorporation observed in 7 after short
(3 hours) and prolonged (24 h) lithiation times with nBuLi/
TMEDA (3.0 equiv.).
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2-Methyl Derivatives of 1,1Ј-Biaryls
FULL PAPER
ture. Mass spectrometry (FAB) studies of this polar band
revealed the presence of mass ions consistent with the for-
mula (11)n (n = 2, 3) with the possibility of higher oligomers
being present as well. Consistent with the presence of mixed
stereoisomers, the 1H and 13C NMR spectra of the mixture
were broad and uninformative. We believe that the failure
of PhP(O)Cl2 electrophile to form chelate 11 effectively is
due to the presence of the smaller oxo phenyl moiety
[P(=O)Ph] which displays a considerably smaller steric de-
mand than a SiPh2 unit. This trend is born out in reactions
of the dianion derived from 7 (either method A or B) with
sterically less demanding PhPCl2. While 31P-NMR studies
of the reaction mixture revealed the presence of the desired
ligand the reaction is even less clean than transformations
using PhP(O)Cl2. Isolation of the derived ligand is compli-
cated by its oxidative and hydrolytic instability.
Figure 5. Molecular structure of (P)-(Rax)-9 [derived from (Sax)-
binol]. Hydrogen atoms omitted for clarity; displacement ellipsoids
drawn at 50% probability level. Selected inter atomic distances [Å]
and angles [°]: Si(1)–O(1) 1.667(2), Si(1)–C(11) 1.866(3), O(1)–
Si(1)–C(11) 104.45(10), C(18)–Si(1)–C(12) 110.37(10); torsion an-
gle C(2)–C(1)–C(1Ј)–C(2Ј) 57.9(3).
Scheme 5. Preparation of phosphane oxide 11a. Reagents and con-
ditions: (i): a) 7 (1 equiv.), nBuLi (3 equiv.), TMEDA (3 equiv.),
Et2O, 0 °C, 24 h. [leads to (P)-(Sax,RP)-11a only]; or b) 7 (1 equiv.),
nBuLi (2.5 equiv.), tBuOK (2.5 equiv.), Et2O, –40 °C, 3 h [leads to
a 5:6 mixture of (P)-(Sax,RP)-11a and its Sp epimer 11b] (ii)
PhP(=O)Cl2 (2.0 or 1.5 equiv.), –60 °C, 3 h.
Figure 6. Molecular structure of 10. Only one of the two crystallo-
graphically independent molecules shown. Hydrogen atoms omit-
ted for clarity; displacement ellipsoids drawn at 50% probability
level. Selected inter atomic distances [Å] and angles [°]: O(7)–Si(9)
1.691(2), O(7a)–Si(9a) 1.6656(14), C(8)–Si(9) 1.759(2), C(8a)–Si(9a)
1.844(2). O(7)–Si(9)–C(8) 103.84(9), O(7a)–Si(9a)–C(8a) 104.34(7),
C(10)–Si(9)–C(16) 110.52(8), C(10a)–Si(9a)–C(16a) 109.62(8); tor-
sion angle C(2)–C(1)–C(1Ј)–C(2Ј) 51.5(3), C(2a)–C(1a)–C(1Јa)–
C(2Јa)–52.6(3).
the 31P NMR spectrum of the reaction mixture is informa-
tive. A resonance at δP 53.51 ppm is observed for (P)-
(Sax,RP)-11a along with traces of a closely related species at
δP 53.35 ppm, proposed to be the phosphorus epimer (P)-
(Sax,SP)-11b. This was confirmed by lithiation using nBuLi/
tBuOK (method B) which led to a 16–18% isolated yield
of 11a/b. However, in this case a mixture of both possible
diastereomers was realised with a SP:RP ratio of 5:6. The
two diastereomers could be separated by careful
chromatography, but attempts to crystallise the minor dia-
stereomer were unsuccessful. As both lithiation methods A
and B resulted in poor yields, attempts were made to ident-
Figure 7. Molecular structure of (P)-(Sax,RP)-11a derived from
(Sax)-binol. Hydrogen atoms omitted for clarity; displacement ellip-
soids drawn at 50% probability level. Selected inter atomic dis-
tances [Å] and angles [°]: P(1)–O 1.691(2), P(1)–O(1) 1.4732(12),
P(1)–C(21) 1.813(2), P(1)–C(22) 1.793(2), C(21)–P(1)–O 102.45(7),
C(22)–P(1)–O(1) 113.45(8); torsion angle C(2)–C(1)–C(11)–C(12)
54.8(2).
Conclusions
We have developed an ultraselective monosulfonylation
ify the mass balance of the reaction. The majority of the of 1,1Ј-binaphthol (1) and structurally related 1,1Ј-biphenol
crude reaction mixture consisted of a very polar yellow derivatives and their subsequent reaction with Tf2O or NfF
compound that could only be eluted from the chromatog- to afford the protected/activated cores 5–6. Chemoselective
raphy columns with neat methanol. The 31P NMR spec- methylation of these cores and subsequent hydrolysis allows
trum of this component displayed a broad signal at δP rapid access to the 2-OH–2Ј-Me species 7–8 in a highly ex-
11.5 ppm, which was also present in the crude reaction mix- pedient process compared to published approaches. Double
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Ar), 127.6 (CH, Ar), 127.5 (2 CH, Ts), 126.7 (CH, Ar), 126.6 (CH,
Ar), 126.3 (CH, Ar), 124.7 (CH, Ar), 123.9 (C, Ar), 123.4 (CH,
Ar), 121.7 (CH, Ar), 118.2 (CH, Ar), 113.8 (C, Ar), 21.6 (CH3,
deprotonation of the 1,1Ј-binaphthyl methyl compound 7
with either nBuLi/TMEDA or nBuLi/tBuOK, followed by
reaction with Cl2SiPh2 leads to 7-ring silanoxanes 9–10 in
good overall yield (38-42%). Using sterically less de-
manding electrophiles (i.e. those lacking the strong Thorpe–
Ingold effect present in Cl2SiPh2), such as PhP(=O)Cl2, po-
orer yields were evidenced in the reaction of the equivalent
dianion derived from 7.
TsCH ) ppm. IR (CCl solution): ν = 3555 (OH), 3061 (CH, Ar),
˜
3
4
1382, 1361 (SO2), 1177 (SO2) cm–1. HRMS (EI): m/z found
440.1082 required 440.1082. C27H20O4S (440.10): calcd. C 73.62 H
4.58 found C 73.59 H 4.70%.
(M)-(Rax)-2-Hydroxy-2Ј-(phenylsulfonyloxy)-1,1Ј-binaphthyl (2b):
Prepared as for 2a starting from (Rax)-binol and benzenesulfonyl
chloride, to give 2b as a colourless solid, 1.34 g, 90%. Rf = 0.27 in
CH2Cl2. M.p. 61–64 °C. [α]2D5 = +44.0 (c = 1.0 in CHCl3). 1H NMR
(400.1 MHz, CDCl3): δ = 8.08 (d, J = 9.0 Hz, 1 H, Ar4or4Ј), 7.98
(d, J = 8.3 Hz, 1 H, Ar5or5Ј), 7.84 (d, J = 8.8 Hz, 1 H, Ar4or4Ј), 7.78
(d, J = 8.1 Hz, 1 H, Ar5or5Ј), 7.72 (d, J = 9.0 Hz, 1 H, Ar3or3Ј), 7.53
(ddd, J1 = 8.1 Hz, J2 = 6.8 Hz, J3 = 1.3 Hz, 1 H, Ar6,6Ј,7or7Ј), 7.40
(tt, J1 = 8.7 Hz, J2 = 1.2 Hz, 1 H, Ph-p), overlapping with 7.36
(ddd, J1 = 6.9 Hz, J2 = 5.5 Hz, J3 = 1.2 Hz, 1 H, Ar6,6Ј,7or7Ј), 7.31
(dd, J1 = 8.4 Hz, J2 = 1.2 Hz, 2 H, Ph-o), overlapping with 7.31–
7.27 (m, 2 H, Ar3or3Ј, Ar6,6Ј,7or7Ј), 7.24 (d, J = 8.9 Hz, 1 H, Ar8or8Ј),
7.18–7.14 (m, 3 H, Ph-m, Ar6,6Ј7or7Ј), 6.88 (d, J = 8.4 Hz, 1 H,
Ar8or8Ј), 4.98 (s, 1 H, OH) ppm. 13C{1H} NMR (100.6 MHz,
CDCl3): δ = 151.6 (C, Ar), 146.3 (C, Ar), 135.8 (C, Ar), 133.7 (C,
Ar), 133.4 (C, Ar), 133.3 (C, Ar), 132.5 (C, Ar), 131.0 (CH, Ar),
130.5 (C, Ar), 128.9 (C, Ar), 128.6 (2 CH, Ar), 128.3 (CH, Ar),
127.9 (CH, Ar), 127.7 (CH, Ar), 127.4 (2 CH, Ar), 126.8 (CH, Ar),
126.7 (CH, Ar), 126.2 (CH, Ar), 124.6 (CH, Ar), 124.0 (CH, Ar),
123.5 (CH, Ar), 121.6 (CH, Ar), 118.0 (CH, Ar), 113.7 (CH, Ar)
Experimental Section
General Methods: Procedures involving air- or moisture-sensitive
reagents/intermediates were performed under a positive pressure of
argon using standard Schlenk techniques. Flash chromatography
was performed using a forced flow with the solvent indicated in the
relevant experimental procedures. Silica gel 60 (220–240 mesh) was
used as the stationary phase (Fluka). Thin-layer chromatography
was performed on pre-coated plates (0.25 mm) silica, with visualis-
ation by UV, KMnO4 or PMA staining. 1H, 13C, 19F and 31P NMR
were recorded with a Bruker (AV400, DPX 300 or DRX 500). All
chemical shifts (δ) were referenced to chloroform and are reported
in parts per million (ppm). Coupling constants (J) are given in Hz.
Assignments to binaphthyl or biphenyl untis are abbreviated “Ar”,
those to tosyl groups “Ts” and to phenylsulfonyl groups “Ph”. IR
spectra were recorded as a solution in chloroform or as specified.
MS were recorded at high resolution with a micromass LCT or
VG micromass 70E mass spectrometer using electrospray ionisation
(ESI), electron impact (EI) or fast atom bombardment (FAB). Ele-
mental analyses were performed with an Exeter Analytical CE-440.
Optical rotations were measured with a JASCO DIP370 Digital
polarimeter and are quoted as 10–1 degcm2 g–1. Concentration (c)
is given as g/100 cm3. Organic solvents were used as supplied or
distilled from suitable drying agents and stored over 4-Å molecular
sieves under argon.[25] (R)- and (S)-binol were purchased from Reu-
ter Chemischer Apparatebau KG, 3,3Ј,5,5Ј-tetramethylbiphenol
was synthesised according to the literature,[26] 2-(di-tert-butylphos-
phanyl)-2Ј,4Ј,6Ј-triisopropyl-1,1Ј-biphenyl (X-Phos) was purchased
from Strem.
ppm. IR (CHCl solution): ν = 3684 (OH), 3035 (CH, Ar), 3010,
˜
3
1239 (SO2), 1194 (SO2) cm–1. HRMS (EI): m/z found 426.0940,
C26H18O4S required 426.0926.
2-Hydroxy-2Ј-tosyloxy-1,1Ј-biphenyl (4a): Prepared as for 3a start-
ing from biphenol to give 4a as a colourless solid, 1.64 g, 90%. Rf
= 0.33 in CH2Cl2. M.p. 115–117 °C. 1H NMR (400.1 MHz,
CDCl3): δ = 7.51 (dd, J1 = 8.1 Hz, J2 = 1.3 Hz, 1 H, Ar), 7.43
(approx. td, J1 = 8.1 Hz, J2 = 1.9 Hz, 1H, Ar), 7.37 (approx. td, J1
= 7.6 Hz, J2 = 1.4 Hz, 1H, Ar), 7.31 (d, J = 1.8 Hz, 1H, Ar), 7.28
(d, J = 8.3 Hz, 2H, Ts), 7.21 (ddd, J1 = 9.0 Hz, J2 = 6.9 Hz, J3 =
2.3 Hz, 1H, Ar), 7.06 (d, J = 8.0 Hz, 2H, Ts), 6.86 (d, J = 6.0 Hz,
1H, Ar), 6.83 (approx. td, J1 = 7.8 Hz, J2 = 0.9 Hz, 1H, Ar), 4.93
(s, OH), 2.38 (s, 3H, CH3) ppm. 13C{1H} NMR (100.6 MHz,
CDCl3): δ = 152.6 (C, Ar), 146.9 (C, Ar), 145.0 (C, Ar), 132.1 (C,
Ar), 132.0 (CH, Ar), 131.1 (CH, Ar), 131.0 (C, Ar), 129.5 (CH,
Ar), 129.5 (2 CH, Ts), 129.4 (CH, Ar), 127.9 (2 CH, Ts), 127.7
(CH, Ar), 123.9 (CH, Ar), 123.6 (C, Ar), 120.5 (CH, Ar), 116.4
(P)-(Sax)-2-Hydroxy-2Ј-tosyloxy-1,1Ј-binaphthyl (2a): (Sax)-Binol
(1.00 g, 3.50 mmol), p-toluenesulfonyl chloride (0.67 g, 3.53 mmol)
and DMAP (0.069 g, 0.57 mmol) were dissolved in 10 mL of freshly
distilled CH2Cl2 and the resulting solution cooled to 0 °C. Neat
NEt3 (0.6 mL, 3.85 mmol) was added dropwise to the solution,
which was then stirred at ambient temperature. After 8 h quantita-
tive yield was obtained (white solid, 1.54 g, 3.50 mmol, 100%). Rf
= 0.45 in CH2Cl2. M.p. 61–62 °C. [α]2D5 = –46.2 (c = 1.00, CHCl3).
Compound 2a could be crystallised as colourless plates of a toluene
monosolvate from toluene/light petroleum. The toluene was re-
(CH, Ar), 21.6 (CH3, Ts) ppm. IR (CHCl3 solution): ν = 3565
˜
(OH), 3069 (CH, Ar), 1474, 1376 (SO2), 1166 (SO2) cm–1. HRMS
(EI): m/z found 340.0768 required 340.0769. C19H16O4S (340.08):
calcd. C 67.04 H 4.74; found C 66.87 H 4.73.
1
moved under prolonged drying. H NMR (400.1 MHz, CDCl3): δ
2-Hydroxy-2Ј-(phenylsulfonyloxy)-1,1Ј-biphenyl (4b): Prepared as
for 3a to give 4b as a colourless solid, 1.28 g, 73%. Rf = 0.33 in
= 8.06 (d, J = 9.0 Hz, 1 H, Ar4or4Ј), 7.97 (d, J = 8.2 Hz, 1 H,
Ar5or5Ј), 7.84 (d, J = 9.0 Hz, 1 H, Ar4or4Ј), 7.78 (d, J = 9.0 Hz, 1 CH2Cl2. M.p. 110–111 °C. 1H NMR (400.1 MHz, CDCl3): δ = 7.53
H, Ar3or3Ј), 7.73 (d, J = 9.2 Hz, 1 H, Ar3or3Ј), 7.51 (approx. t, J = (tt, J1 = 8.8 Hz, J2 = 1.2 Hz, 1 H, Ar), 7.52 (dd, J1 = 8.4 Hz, J2 =
7.5 Hz plus unresolved long-range coupling, 1H, Ar6,6Ј,7or7Ј), 7.33
(approx. t, J = 7.5 plus unresolved long-range coupling, 1H,
Ar6,6Ј,7or7Ј), 7.40–7.28 (m, 5H, toluene), 7.23 (d, J = 8.2 Hz, 2H,
Ts) overlapped by 7.22–7.14 (m, 4H, Ar8or8Ј, Ar6,6Ј,7or7Ј, Ar3or3Ј),
6.91 (d, J = 8.2 Hz, 2H, Ts), 6.83 (d, J = 8.4 Hz, plus unresolved
long-range coupling, 1H, Ar8or8Ј), 5.05 (s, 1H, OH), 2.40 (s, 3H,
1.0 Hz, 1 H, Ar), 7.44 (ddd, J1 = 8.1 Hz, J2 = 7.3 Hz, J3 = 1.9 Hz,
1 H, Ar), 7.42 (dd, J1 = 6.6 Hz, J2 = 1.4 Hz, 2 H, Ar), 7.38 (approx.
td, J1 = 7.4 Hz, J2 = 1.4 Hz, 1 H, Ar), 7.32–7.27 (m, 3 H, Ts, Ar),
7.21 (ddd, J1 = 9.0 Hz, J2 = 6.9 Hz, J3 = 2.2 Hz, 1 H, Ar), 6.87–
6.84 (m, 2 H, Ar), 6.82 (dd, J1 = 7.5 Hz, J2 = 1.2 Hz, 1 H, Ar),
4.87 (s, 1 H, OH) ppm. 13C{1H} NMR (100.6 MHz, CDCl3): δ =
CH3), 2.33 (s, 3H, toluene). 13C{1H} NMR (100.6 MHz, CDCl3): 152.6 (C, Ar), 146.9 (C, Ar), 135.3 (C, Ar), 133.8 (CH, Ar), 132.1
non solvate: δ = 151.6 (C, Ar), 146.4 (C, Ar), 144.7 (C, Ar), 133.4
(2 C, Ar), 132.7 (C, Ar), 132.5 (C, Ar), 131.0 (CH, Ar), 130.4 (CH,
(CH, Ar), 131.1 (CH, Ar), 131.0 (C, Ar), 129.6 (CH, Ar), 129.5
(CH, Ar), 128.9 (2 CH, Ts), 127.9 (2 CH, Ts), 127.8 (CH, Ar),
Ar), 129.3 (2 CH, Ts), 128.9 (C, Ar), 128.3 (CH, Ar), 127.8 (CH, 123.9 (CH, Ar), 123.4 (C, Ar), 120.7 (CH, Ar), 116.4 (CH, Ar)
1618
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© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2007, 1613–1623

2-Methyl Derivatives of 1,1Ј-Biaryls
FULL PAPER
ppm. IR (CHCl solution): ν = 3564 (OH), 1450, 1377 (SO ), 1165
chilled residual oil, followed by agitation, filtration and further
washing in 1:1 MeOH/water.
˜
3
2
(SO2) cm–1. HRMS (EI): m/z found 326.0609 required 326.0613.
C18H14O4S (326.06): calcd. C 66.25 H 4.32; found C 65.94 H 4.31.
(M)-(Rax)-2-(Trifluoromethoxy)-2Ј-(phenylsulfonyloxy)-1,1Ј-binaph-
2-Hydroxy-3,3Ј,5,5Ј-tetramethyl-2Ј-tosyloxy-1,1Ј-biphenyl (4c): Pre- thyl (5b): Prepared as for 5a starting from (Rax)-binol and ben-
pared as for 2a starting from 3,5,3Ј,5Ј-tetramethyl-1,1Ј-biphenol to
give 4c as a colourless solid, 1.63 g, 99%. Rf = 0.25 in CH2Cl2/
light petroleum ether, 1:1. M.p. 115–116 °C. 1H NMR (400.1 MHz,
CDCl3): δ = 7.26 (approx. d, J = 8.2 Hz, 2 H, Ts), 7.12 (dd, J1 =
1.6 Hz, J2 = 0.7 Hz, 1 H, Ar), 7.04 (approx. d, J = 8.2 Hz, 2 H,
Ts), 6.93 (approx. d, J = 2.2 Hz, 1 H, Ar), 6.73 (dd, J1 = 1.5 Hz,
J2 = 0.7 Hz, 1 H, Ar), 6.59 (approx. d, J = 2.1 Hz, 1 H, Ar), 4.83
(br. s, 1 H, OH), 2.49 (s, 3 H, Ts-CH3), 2.37 (s, 3 H, CH3), 2.32 (s,
zenesulfonyl chloride to give 5b as a colourless solid, 1.64 g, 84%.
Rf = 0.46 in CH2Cl2/light petroleum ether, 1:1. M.p. 100–102 °C.
1
[α]2D5 = –101.9 (c = 1.0, CHCl3). H NMR (400.1 MHz, CDCl3): δ
= 8.07 (d, J = 9.0 Hz, 1 H, Ar4or4Ј), 7.95 (d, J = 8.9 Hz, 1 H,
Ar5or5Ј) overlapped by 7.95 (d, J = 9.2 Hz, 1 H, Ar4or4Ј), 7.88 (d, J
= 8.2 Hz, 1 H, Ar5or5Ј), 7.75 (d, J = 9.0 Hz, 1 H, Ar3or3Ј), 7.51 (ddd,
J1 = 7.8 Hz, J2 = 5.3 Hz, J3 = 1.3 Hz, 1 H, Ar6,6Ј,7or7Ј), overlapping
with 7.49 (ddd, J1 = 8.2 Hz, J2 = 5.3 Hz, J3 = 1.2 Hz, 1 H,
3 H, CH3), 2.11 (s, 3 H, CH3), 2.09 (s, 3 H, CH3) ppm. 13C{1H} Ar6,6Ј,7or7Ј), 7.45 (d, J = 9.2 Hz, 1 H, Ar3or3Ј), 7.30 (ddd, J1 = 8.9,
NMR (100.6 MHz, CDCl3): δ = 148.5 (C, Ar), 144.5 (C, Ar), 144.1
(C, Ar), 137.3 (C, Ar), 133.8 (C, Ar), 133.7 (C, Ar), 132.3 (CH,
Ar), 131.3 (C, Ar), 131.0 (CH, Ar), 130.3 (CH, Ar), 129.0 (2 C,
Ar), 128.9 (C, Ar), 128.8 (CH, Ar), 127.3 (2 C, Ar), 124.8 (C, Ar),
124.0 (C, Ar), 21.6 (Ts-CH3), 20.8 (CH3), 20.3 (CH3), 17.8 (CH3),
J2 = 6.8, J3 = 1.2 Hz, 1 H, Ar6,6Ј,7or7Ј) overlapping with 7.28 (ddd,
J1 = 7.8, J2 = 6.9, J3 = 1.3 Hz, 1 H, Ar6,6Ј,7or7Ј), 7.27-7.24 (m, 1 H,
Ph-p), 7.22 (approx. d, J1 = 8.4, J2 = 1.2 Hz, 2 H, Ph-o), 7.06
(approx. t, J = 8.7 Hz, 2 H, Ph-m), 7.02 (d, J = 7.8 Hz, 1 H,
Ar8or8Ј), 7.00 (d, J = 7.8 Hz, 1 H, Ar8or8Ј) ppm. 13C{1H} NMR
(100.6 MHz, CDCl3): δ = 145.8 (C, Ar), 145.2 (C, Ar), 135.8 (C,
Ar), 133.4 (CH, Ar), 133.2 (C, Ar), 133.0 (C, Ar), 132.0 (C, Ar),
131.8 (C, Ar), 131.2 (CH, Ar), 130.9 (CH, Ar), 128.4 (2 C, Ph),
128.2 (CH, Ar), 128.0 (CH, Ar), 127.6 (CH, Ar), 127.2 (CH, Ar),
127.1 (CH, Ar), 127.1 (2 C, Ph), 126.8 (CH, Ar), 126.5 (CH, Ar),
126.4 (CH, Ar), 124.5 (C, Ar), 122.2 (C, Ar), 131.2 (CH, Ar), 119.2
(CH, Ar), 118.0 (q, JCF = 320.3 Hz, CF3) ppm. 19F{1H} NMR
(282.4 MHz, CDCl3): δ = –74.82 (s, CF3) ppm. IR (CHCl3 solu-
16.1 (CH ) ppm. IR (CHCl solution): ν = 3556 (OH), 2923 (CH,
˜
3
3
Ar), 1462, 1321 (SO2), 1146 (SO2) cm–1. HRMS (EI): m/z found
396.1386 required 396.1395. C23H24O4S (396.14): calcd. C 69.67 H
6.10; found C 69.39 H 6.12.
(P)-(Sax)-2-(Trifluoromethoxy)-2Ј-tosyloxy-1,1Ј-binaphthyl
(5a):
(Sax)-Binol ent-1a (5.11 g, 17.86 mmol), p-toluenesulfonyl chloride
(3.40 g, 17.89 mmol) and DMAP (0.35 g, 2.85 mmol) were dis-
solved in 50 mL of freshly distilled CH2Cl2 and the resulting solu-
tion cooled to 0 °C. Neat NEt3 (8.4 mL, 53.7 mmol) was added
dropwise to the solution. The reaction mixture was stirred for 12 h
at ambient temperature. After this time, trifluoromethanesulfonic
anhydride (5.54 g, 19.65 mmol) was added slowly at 0 °C to the
reaction mixture and stirring continued for another 12 h. The or-
ganic layer was washed with 1  HCl (3ϫ100 mL) and with water
(3ϫ100 mL), dried with MgSO4 and the solvent removed in vacuo.
Crystallization from boiling MeOH or from CH2Cl2/hexane (1:6)
afforded 5a as colourless microneedles (9.89 g, 17.28 mmol, 97%).
Rf = 0.51 in CH2Cl2/light petroleum ether, 1:1. M.p. 159–161 °C.
tion): ν = 1376 (SO ), 1140 (SO ), 1093, 1067, 969 cm–1. HRMS
˜
2
2
(EI): m/z found 558.0426 required 558.0419. C27H17F3O6S2
(558.55): calcd. C 58.06, H 3.07; found C 57.92, H 3.01.
(M)-(Rax)-2-Nonaflyloxy-2Ј-tosyloxy-1,1Ј-binaphthyl (5c): Prepared
as for 5a from (Rax)-binol and CF3(CF2)3SO2F to give 5c as a
colourless powder, 11.5 g, 91%. Rf = 0.54 in CH2Cl2/light petro-
leum ether, 1:1. M.p. 128–131 °C. [α]2D5 = –94.6 (c = 1.0, CHCl3).
1H NMR (400.1 MHz, CDCl3): δ = 8.06 (d, J = 9.1 Hz, 1 H,
Ar4or4Ј), 7.97 (d, J = 8.6 Hz, 1 H, Ar5or5Ј), 7.94 (d, J = 9.2 Hz, 1
H, Ar4or4Ј), 7.88 (d, J = 8.8 Hz, 1 H, Ar5or5Ј), 7.76 (d, J = 9.1 Hz,
1 H, Ar3or3Ј), 7.52–7.46 (m, 2 H, Ar6,6Ј,7or7Ј) overlapped by 7.50 (d,
J = 9.2 Hz, 1 H, Ar3or3Ј), 7.28 (ddd, J1 = 8.6 Hz, J2 = 6.8 Hz, J3 =
[α]2D5 = +108.0 (c = 1.00, CHCl3). H NMR (400.1 MHz, CDCl3):
1
δ = 8.07 (d, J = 9.0 Hz, 1 H, Ar4or4Ј), 7.97 (d, J = 8.8 Hz, 1 H,
Ar5or5Ј), 7.95 (d, J = 8.5 Hz, 1 H, Ar4or4Ј), 7.89 (d, J = 8.2 Hz, 1 1.2 Hz, 1 H, Ar6,6Ј,7or7Ј), 7.22 (ddd, J1 = 8.6 Hz, J2 = 6.8 Hz, J3 =
H, Ar5or5Ј), 7.78 (d, J = 9.0 Hz, 1 H, Ar3or3Ј), 7.53–7.46 (m, 2 H, 1.2 Hz, 1 H, Ar6,6Ј,7or7Ј), 7.07 (approx. d, J = 8.4 Hz, 2 H, Ts-o),
Ar6,6Ј,7or7Ј) overlapped by 7.48 (d, J = 8.5 Hz, 1 H, Ar3or3Ј), 7.28
(ddd, J1 = 8.5 Hz, J2 = 6.9 Hz, J3 = 1.3 Hz, 1 H, Ar6,6Ј,7or7Ј), 7.22
(ddd, J1 = 8.5 Hz, J2 = 6.9 Hz, J3 = 1.2 Hz, 1 H, Ar6,6Ј,7or7Ј) 7.08
(approx. d, J = 8.2 Hz, 2 H, Ts), 7.05 (d, J = 8.5 Hz, plus unre-
solved long-range couplings,1 H, Ar8or8Ј), 6.98 (d, J = 8.5 Hz, plus
unresolved long-range couplings,1 H, Ar8or8Ј), 6.74 (approx. d, J =
7.05 (dd, J1 = 8.6, J2 = 0.5 Hz, 1 H, Ar8or8Ј), 6.98 (dd, J1 = 8.5 Hz,
J2 = 0.7 Hz, Ar8or8Ј), 6.74 (approx. d, J1 = 8.0 Hz, 2 H, Ts-m), 2.23
(s, 3 H, CH3) ppm. 13C{1H} NMR (100.6 MHz, CDCl3): δ = 146.0
(C, Ar), 145.4 (C, Ar), 144.4 (C, Ar), 133.1 (C, Ar), 133.0 (C, Ar),
132.8 (C, Ar), 132.0 (C, Ar), 131.8 (C, Ar), 131.1 (CH, Ar), 130.9
(CH, Ar), 129.1 (2 CH, Ts), 128.1 (CH, Ar), 127.9 (CH, Ar), 127.4
8.2 Hz, 2 H, Ts), 2.22 (s, 3 H, TsCH3) ppm. 13C{1H} NMR (CH, Ar), 127.2 (CH, Ar), 127.1 (3 CH, Ts, Ar), 126.6 (CH, Ar),
(100.6 MHz, CDCl3): δ = 145.9 (C, Ar), 145.2 (C, Ar), 144.4 (C,
Ar), 133.1 (C, Ar), 132.9 (C, Ar), 132.7 (C, Ar), 132.0 (C, Ar),
126.5 (CH, Ar), 126.3 (CH, Ar), 124.7 (C, Ar), 122.1 (C, Ar), 121.4
(CH, Ar), 119.3 (CH, Ar) 21.5 (CH3, Ts) ppm. 19F{1H} NMR
131.8 (C, Ar), 131.2 (CH, Ar), 130.8 (CH, Ar), 129.1 (2 CH, Ts), (282.4 MHz, CDCl3): δ = –81.2 (t, J = 9.0 Hz, CF2), –110.6 (q, J
129.0 (CH, Ar), 128.2 (CH, Ar), 127.9 (CH, Ar), 127.4 (CH, Ar), = 14.9 Hz, CF3), –121.6 (approx. s, CF2), –126.4 (t, J = 14.5 Hz,
127.2 (2 CH, Ts), 127.1 (CH, Ar), 126.6 (CH, Ar), 126.5 (CH, Ar), CF ) ppm. IR (CHCl solution): ν = 1376 (SO ), 1173 (SO ), 1145
˜
2
3
2
2
126.3 (CH, Ar), 124.6 (C, Ar), 122.1 (C, Ar), 121.4 (CH, Ar), 119.3
(CH, Ar), 118.0 (q, JCF = 320 Hz, CF3), 21.6 (CH3, Ts) ppm.
19F{1H} NMR (282.4 MHz, CDCl3): δ = –75.7 (s, CF3) ppm. IR
(CF3), 969, 942 cm–1. HRMS (EI): m/z found: 722.0462 required
722.0479. C31H19F9O6S2 (722.60): calcd. C 51.53, H 2.65; found C
51.32, H 2.46.
(CCl4 solution): ν = 3060 (CH, Ar), 3018 (CH, Ar), 1625, 1172
˜
2Ј-Tosyloxy-2-(trifluoromethoxy)-1,1Ј-biphenyl (6a): Prepared as for
5a from 1,1Ј-biphenol to give 6a as a colourless solid 12.4 g, 98%.
Rf = 0.51 in CH2Cl2/light petroleum ether, 1:1. M.p. 64–66 °C. H
(SO2), 1365 (SO2) cm–1. HRMS (FAB): m/z found 572.0579 re-
quired 572.0575. C28H19F3O6S2 (572.06): calcd.
3.34;found C 58.67 H 3.19.
C 58.73 H
1
NMR (CDCl3): δ = 7.45 (ddd, J1 = 8.8 Hz, J2 = 7.1 Hz, J3
=
On this and larger scales, solid crude 5a could also be isolated
directly by removal of the CH2Cl2 reaction solvent followed by ad-
dition of MeOH/water (1:1, 100 mL per 15 mmol of 5a) to the
1.8 Hz, 1 H, Ar), 7.43–7.39 (m, 2 H, Ar), 7.38 (ddd, J1 = 7.6 Hz,
J2 = 7.2 Hz, J3 = 1.5 Hz, 1 H, Ar), 7.32 (approx. d, J = 8.3 Hz, 2
H, Ts-o), 7.29–7.25 (m, 3 H, Ar), 7.11 (approx. d, J = 8.3 Hz, 2 H,
Eur. J. Org. Chem. 2007, 1613–1623
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1619

M. Solinas, R. E. Meadows, C. Wilson, A. J. Blake, S. Woodward
FULL PAPER
Ts-m), 7.06 (dd, J1 = 8.0 Hz, J2 = 1.7 Hz, 1 H, Ar) 2.43 (s, 3 H, 132.5 (CH, Ar), 132.0 (CH, Ar), 131.9 (C, Ar), 131.0 (CH, Ar),
CH3) ppm. 13C{1H} NMR (100.6 MHz, CDCl3): δ = 146.8 (C, Ar),
146.7 (C, Ar), 145.0 (C, Ar), 132.7 (C, Ar), 132.4 (CH, Ar), 131.9
131.0 (C, Ar), 130.4 (C, Ar), 130.2 (CH, Ar), 129.0 (2 CH, Ts),
127.0 (2 CH, Ts) 21.5 (CH3, Ts), 20.6 (2 CH3), 17.4 (CH3), 17.0
(CH, Ar), 130.5 (C, Ar), 130.2 (CH, Ar), 129.6 (2 CH, Ts), 129.6 (CH3) ppm. 19F{1H} NMR (282.4 MHz, CDCl3): δ = –81.2 (d, J
(CH, Ar), 129.4 (C, Ar), 127.9 (2 CH, Ts, Ar), 127.2 (CH, Ar),
= 8.8 Hz, CF2), –111.3 (t, J = 13.7 Hz, CF3), –121.5 (approx. s,
123.1 (CH, Ar), 121.2 (CH, Ts), 21.7 (CH3, Ts-CH3) ppm. 19F{1H} CF ), –126.5 (t, J = 13.9 Hz, CF ) ppm. IR (CHCl solution): ν =
˜
2
2
3
NMR (282.4 MHz, CDCl3): δ = –75.4 (s, CF3) ppm. IR (CHCl3 2925 (Ar CH), 1598, 1367 (SO2), 1170 (SO2), 1137 (CF2 or CF3)
solution): ν = 1401, 1377 (SO ), 1139 (SO ), 1090 (CF), 892 cm–1.
HRMS (EI): m/z found: 472.0275 required 472.0262.
cm–1. HRMS (EI) found 678.0769 required 678.0792.
C23H15F9O6S2 (678.08): calcd. C 47.79 H 3.42 found C 47.54 H
˜
2
2
C20H15F3O6S2 (472.46): calcd. C 50.84, H 3.20; found C 50.89, H 3.29%.
3.09.
(P)-(Sax)-2-Hydroxy-2Ј-methyl-1,1Ј-binaphthyl (7): To a solution of
5a (5.5 g, 9.61 mmoL) and Ni(dppe)Cl2 (0.355 g, 0.67 mmol) in
100 mL of freshly distilled THF, a solution of MeMgBr in Et2O
(28.8 mmol) was added dropwise at 0 °C. The reaction mixture was
warmed to ambient temperature and then stirred at 60 °C for 20 h.
Completion of the coupling was indicated by the reaction mixture
turning deep orange-brown from its original lemon yellow colour
and by TLC analysis. Unreacted MeMgBr was quenched with
methanol (10 mL). An aqueous solution of KOH (11 g in 75 mL
of H2O) was then added and the reaction mixture stirred at 80 °C
for 12 h. The reaction mixture was acidified with diluted HCl (1 )
and extracted with CH2Cl2. The organic layers were dried with
MgSO4 and the solvent removed in vacuo. The crude product was
purified by column chromatography to give 7 as a colourless solid
(1.8 g, 6.34 mmol, 66%) Rf = 0.33 Et2O/light petroleum ether, 1:5.
M.p. 125–127 °C. [α]2D5 = +87.0 (c = 1.00, CHCl3). 1H NMR
(400.1 MHz, CDCl3): δ = 7.95 (d, J = 8.5 Hz, 1 H, Ar4or4Ј), 7.91
(approx. d, J = 8.8 Hz, 2 H, Ar5or5Ј overlapped by Ar4or4Ј), 7.87 (d,
J = 8.1 Hz, 1 H, Ar5or5Ј), 7.56 (d, J = 8.5 Hz, 1 H, Ar3or3Ј), 7.45
(ddd, J1 = 8.1 Hz, J2 = 6.7 Hz, J3 = 1.3 Hz, 1 H, Ar6,6Ј,7or7Ј), 7.35
(d, J = 8.8 Hz, 1 H, Ar3or3Ј) overlapped by 7.34–7.20 (m, 5 H,
Ar6,6Ј,7or7Ј and Ar8or8Ј), 6.98 (d, J = 8.4 Hz plus unresolved long-
range coupling, 1 H, Ar8,8Ј), 4.77 (s, 1 H, OH), 2.15 (s, 3 H, CH3)
ppm. 13C{1H} NMR (100.6 MHz, CDCl3): δ = 150.7 (C, Ar), 137.2
(C, Ar), 133.3 (C, Ar), 133.2 (C, Ar), 132.5 (C, Ar), 129.8 (CH,
Ar), 129.1 (C, Ar), 129.0 (CH, Ar), 128.9 (C, Ar), 128.6 (CH, Ar),
128.1 (2 CH, Ar), 126.8 (CH, Ar), 126.7 (CH, Ar), 125.5 (CH, Ar),
125.4 (CH, Ar), 124.5 (CH, Ar), 123.4 (CH, Ar), 117.5 (C, Ar),
3,3Ј,5,5Ј-Tetramethyl-2Ј-tosyloxy-2-(trifluoromethoxy)-1,1Ј-biphenyl
(6b): Prepared as for 5a starting from 3,3Ј,5,5Ј-tetramethyl-1,1Ј-bi-
phenol 3b to give 6b as a colourless solid, 1.64 g, 75%. Rf = 0.53
in CH2Cl2/light petroleum ether, 1:1. M.p. 84–86 °C. 1H NMR
(400.1 MHz, CDCl3): δ = 7.33 (approx. d, J = 8.2 Hz, 2 H, Ts-o),
7.12 (dd, J1 = 1.6 Hz, J2 = 0.7 Hz, 1 H, Ar), 7.08 (approx. d, J =
8.2 Hz, 2 H, Ts-m), 6.95 (approx. d, J = 2.2 Hz, 1 H, Ar), 6.88–
6.86 (m, 2 H, Ar), 2.42 (s, 3 H, Ts-CH3), 2.39 (s, 3 H, CH3), 2.33
(s, 3 H, CH3), 2.26 (s, 3 H, CH3), 2.16 (s, 3 H, CH3) ppm. 13C{1H}
NMR (100.6 MHz, CDCl3): δ = 144.1 (C, Ar), 144.0 (C, Ar), 143.1
(C, Ar), 137.7 (C, Ar), 136.7 (C, Ar), 134.4 (C, Ar), 132.9 (C, Ar),
132.6 (CH, Ar), 131.9 (CH, Ar), 131.7 (C, Ar), 130.9 (CH, Ar),
130.9 (C, Ar), 130.3 (CH, Ar), 130.2 (C, Ar), 129.0 (2 CH, Ts),
127.1 (2 CH, Ts), 118.0 (q, JCF = 320.4 Hz, CF3), 21.5 (CH3, Ts),
20.7 (CH3), 20.7 (CH3), 17.5 (CH3), 17.0 (CH3) ppm. 19F{1H}
NMR (282.4 MHz, CDCl3): δ = –75.1 (s, CF3) ppm. IR (CHCl3
solution): ν = 2924 (CH, Ar), 1402, 1367 (SO ), 1170 (SO ) cm–1.
˜
2
2
HRMS (EI) found 528.0912 required 528.0888. C24H23F3O6S2
(528.09): calcd. C 54.54 H 4.39; found C 54.25 H 4.26.
2Ј-Nonaflyloxy-2-(trifluoromethoxy)-1,1Ј-biphenyl (6c): Prepared as
for 5c starting from 1,1Ј-biphenol to give 6c as a colourless solid,
3.0 g, 90%. Rf 0.56 in CH2Cl2/light petroleum ether, 1:1. M.p. 68–
1
70 °C. H NMR (400.1 MHz, CDCl3): δ = 7.44 (ddd, J1 = 8.4 Hz,
J2 = 7.1 Hz, J3 = 1.8 Hz, 1 H, Ar), overlapped with 7.43–7.40 (m,
1 H, Ar), 7.41 (ddd, J1 = 7.4 Hz, J2 = 1.6 Hz, J3 = 1.2 Hz, 1 H,
Ar), 7.37 (dd, J1 = 7.6 Hz, J2 = 1.5 Hz, 1 H, Ar), 7.33 (approx. d,
J = 8.0 Hz, 2 H, Ts-o), 7.28 (dd, J1 = 7.6 Hz, J2 = 1.5 Hz, 2 H,
Ar), 7.28 (td, J1 = 7.5 Hz, J2 = 1.2 Hz, 1 H, Ar), 7.11 (approx. d,
J = 8.0 Hz, 2 H, Ts-m), 7.06 (dd, J1 = 7.6 Hz, J2 = 1.7 Hz, 1 H,
Ar) ppm. 13C{1H} NMR (100.6 MHz, CDCl3): δ = 146.9 (C, Ar),
146.8 (C, Ar), 144.9 (C, Ar), 132.7 (C, Ar), 132.3 (CH, Ar), 131.8
(CH, Ar), 130.6 (C, Ar), 130.1 (CH, Ar), 129.6 (2 CH, Ts), 129.6
(CH, Ar), 129.5 (C, Ar), 127.9 (CH, Ar), 127.9 (2 CH, Ts), 127.1
(CH, Ar), 123.0 (CH, Ar), 121.2 (CH, Ar), 21.5 (CH3, Ts) ppm.
19F{1H} NMR (282.4 MHz, CDCl3): δ = –81.2 (t, J = 8.3 Hz, CF2),
–110.5 (approx. s, CF3), –121.5 (approx. s, CF2), –126.4 (t, J =
117.4 (CH, Ar), 20.1 (CH3, Bz) ppm. IR (CHCl3 solution): ν =
˜
3534 (OH), 1620, 1597 (Ar C=C), 1346, 1128 cm–1. HRMS (EI)
found 284.1203, C21H16O required 284.1201. These values are con-
cordant with those published for
7 obtained by alternative
routes.[27]
2-Hydroxy-2Ј-methyl-1,1Ј-biphenyl (8): To a solution of 6a (0.472 g,
1.0 mmol), Pd2(dba)3 (0.027 g, 0.03 mmol) and X-Phos (0.021,
0.05 mmol) in freshly distilled THF (8 mL) under argon, was added
(AlMe3)2(DABCO) (0.0205 g, 0.8 mmol) in THF (8 mL). The reac-
tion was then heated to reflux overnight. The reaction mixture was
then cooled to ambient temperature and a solution of KOH
(0.561 g, 10.0 mmol) in MeOH (5 mL) and water (5 mL) was
added. The reaction mixture was then left to reflux for 4 h. After
this time, the reaction mixture was acidified with diluted HCl (1 )
and extracted with CH2Cl2. The organic phase was dried with
MgSO4, filtered and the solvent removed in vacuo. The crude prod-
uct was purified by column chromatography to give 6a as a pale
yellow viscous oil (0.156 g, 0.85 mmol, 85%). Rf = 0.31 CH2Cl2/
13.7 Hz, CF2) ppm. IR (CHCl3 solution): ν = 1598, 1401, 1378
˜
(SO2), 1139 (SO2), 1090 (CF2 or CF3) cm–1. HRMS (EI) found
622.0164 required 622.0166. C27H23F9O6S2 (622.02): calcd. C 44.37
H 2.43; found C 44.33 H 2.45.
3,3Ј,5,5Ј-Tetramethyl-2Ј-tosyloxy-2-(trifluoromethoxy)-1,1Ј-biphenyl
(6d): Prepared as for 5c starting from 3,3Ј,5,5Ј-tetramethyl-1,1Ј-bi-
phenol 3b to give 6d as a colourless solid, 1.24 g, 93%. Rf 0.32
in CH2Cl2/light petroleum ether, 1:1. M.p. 100–101 °C. 1H NMR
(400.1 MHz, CDCl3): δ = 7.33 (approx. d, J = 8.2 Hz, 2 H, Ts-o), light petroleum ether, 1:1. 1H NMR (400.1 MHz, CDCl3): δ = 7.37–
7.12 (dd, J1 = 1.6, J2 = 0.7 Hz, 1 H, Ar), 7.08 (approx. d, J =
7.28 (m, 5 H, Ar), 7.14 (dd, J1 = 7.3 Hz, J2 = 1.6 Hz, 1 H, Ar),
8.2 Hz, 2 H, Ts-m), 6.95 (approx. d, J = 2.2 Hz, 1 H, Ar), 6.88– 7.01 (ddd, J1 = 8.6 Hz, J2 = 7.4 Hz, J3 = 1.1 Hz, 1 H, Ar) over-
6.86 (m, 2 H, Ar), 2.42 (s, 3 H, Ts-CH3), 2.39 (s, 3 H, CH3), 2.33 lapped with 7.01 (ddd, J1 = 8.6 Hz, J2 = 7.4 Hz, J3 = 1.1 Hz, 1 H,
(s, 3 H, CH3), 2.26 (s, 3 H, CH3), 2.16 (s, 3 H, CH3) ppm. 13C{1H} Ar), 4.81 (s, 1 H, OH), 2.20 (s, 3 H, CH3) ppm. 13C{1H} NMR
NMR (100.6 MHz, CDCl3): δ = 144.1 (C, Ar), 144.0 (C, Ar), 142.8
(C, Ar), 137.8 (C, Ar), 136.7 (C, Ar), 134.4 (C, Ar), 132.8 (C, Ar),
(100.6 MHz, CDCl3): δ = 152.5 (C, Ar), 137.4 (C, Ar), 135.7 (C,
Ar), 130.7 (CH, Ar), 130.4 (CH, Ar), 130.1 (CH, Ar), 129.1 (CH,
1620
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© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2007, 1613–1623

2-Methyl Derivatives of 1,1Ј-Biaryls
FULL PAPER
Ar), 128.5 (CH, Ar), 127.7 (C, Ar), 126.4 (CH, Ar), 120.4 (CH,
give 10 as a colourless solid (0.36 g, 1.0 mmol, 56%). M.p. 146–
148 °C. 1H NMR (400.1 MHz, CDCl3): δ = 7.41 (approx. d, J =
6.5 Hz, 2 H, Ar4and4Ј), 7.52–7.23 (m, 10 H, Ar and Ph), 7.19 (ap-
prox. td, J1 = 7.5 Hz, J2 = 1.4 Hz, 1 H, Ar5or5Ј), 7.15 (approx. td,
J1 = 7.5 Hz, J2 = 1.2 Hz, 1 H, Ar5or5Ј), 7.03 (t, J = 8.1 Hz plus
unresolved long-range couplings, 2 H, Php), 2.82 (d, J = 14.1 Hz,
1 H, CH2α), 2.52 (d, J = 14.1 Hz, 1 H, CH2β) ppm. 13C{1H} NMR
(100.6 MHz, CDCl3): δ = 152.3 (C–O), 137.7 (C–CH2), 135.8 (C,
Ar), 134.7 (CH, Ar), 134.3 (CH, Ar), 132.7 (C, Ar), 131.3 (CH,
Ar), 130.5 (C, Ar), 130.4 (C, Ar), 129.1 (CH, Ar), 128.9 (CH, Ar),
128.1 (CH, Ar), 127.6 (2 CH, 2ϫPhp), 125.6 (CH, Ar), 122.8 (CH,
Ar), 121.6 (CH, Ar), 22.3 (CH2) ppm. The Ar and Ph substituents
Ar), 115.3 (CH, Ar), 19.7 (CH , Bz) ppm. IR (CHCl solution): ν
˜
3
3
= 3544 (OH), 2925 (Ar CH), 1476 (Ar C=C), 1337, 1152 cm–1.
HRMS (ESI) found 183.0815, C13H11O (M – H) required 183.0877
(M – H).
Lithiation of 7 and 8. Method A: To a solution of 7 or 8 (0.2 mmol)
in Et2O (2 mL), n-butyllithium (0.24 mL of a 2.5  solution in hex-
anes) was added dropwise at 0 °C. To this pale yellow solution
N,N,NЈ,NЈ-tetramethylethylenediamine (TMEDA) was added
(70 mg, 0.6 mmol) and the reaction mixture was stirred at 0 °C for
24 h. The dark red slurry was then cooled to –60 °C and the appro-
priate amount of electrophile (2.0 equiv.) was added to the mixture
(in the case of the D2O experiment, 0.3 mL were used). The organic
layer was washed with 1  HCl (3ϫ5 mL) and dried with MgSO4.
The solvent was removed in vacuo and the crude reaction mixture
was analysed by 1H NMR spectroscopy. 97% of the corresponding
[D1]-7 (δ = 2.17 ppm, t, JHD = 2.2 Hz) was confirmed by NMR
studies.
could not be easily distinguished. IR (CHCl3 solution): ν = 2936
˜
(Ar CH), 1492, 1121 (d for SiPh2), 905 (Si–O–Ar) cm–1. HRMS
(EI) found 364.1297 required 364.1283. C25H20OSi (364.12): calcd.
C 82.38, H 5.53; found C 81.98, H 5.55.
(P)-(Sax,SP)-4-Phenyl-5H-3-oxa-4-phosphacyclohepta[2,1-a;3,4-aЈ]-
dinaphthalene 4-Oxide (11a): A slurry of the red dilithium salt of 7
(0.52 g, 1.8 mmol), prepared according to method A, was cooled
to –60 °C and phenylphosphonic dichloride (0.78 g, 4.0 mmol) was
added. The reaction mixture was stirred for 3 h while warming to
ambient temperature. The crude reaction mixture was then filtered
through celite and washed with water. The organic layers were ex-
tracted with CH2Cl2, dried with MgSO4 and the solvent removed
in vacuo. The solid obtained was then purified by column
chromatography (CH2Cl2/Et2O, 8.5:1.5) to give 11a as one distere-
omer (white solid, 0.12 g, 0.30 mmol, 17%). Rf = 0.38. M.p. 200–
Lithiation of 7 and 8. Method B: A solution of 7 or 8 (0.2 mmol)
and tBuOK (56 mg, 0.5 mmol) in Et2O (2 mL) was cooled to
–40 °C. n-Butyllithium (0.2 mL of a 2.5  solution in hexanes) was
added dropwise and the reaction mixture stirred for 3 h. The dark
red slurry was then cooled to –60 °C and the appropriate amount
of electrophile (1.5 equiv.) was added to the mixture (in the case of
the D2O experiment, 0.3 mL were used). The organic layer was
washed with 1  HCl (3ϫ5 mL) and dried with MgSO4. The sol-
vent was removed in vacuo and the crude reaction mixture was
analysed by 1H NMR spectroscopy. 95% of the corresponding
[D1]-7 (δ = 2.17 ppm, t, JHD = 2.2 Hz) was confirmed by NMR
studies.
1
202 °C. [α]2D5 = + 203.0 (c = 0.17, CHCl3). H NMR (500.1 MHz,
CDCl3): δ = 8.06 (d, J = 8.8 Hz, 1 H, Ar4,4Ј,5,or5Ј), 7.98 (d, J =
8.2 Hz, 1 H, Ar4,4Ј,5,or5Ј), 7.93 (d, J = 8.2 Hz, 1 H, Ar4,4Ј,5,or5Ј), 7.80
(d, J = 8.4 Hz, 1 H, Ar4,4Ј,5,or5Ј), 7.68 (d, J = 8.8 Hz, 1 H, Ar3or3Ј),
7.48 (br., 3 H, Ar and Ph), 7.39 (d, J = 8.4 Hz, 1 H, Ar3or3Ј), over-
lapped by 7.40–7.22 (m, 7 H, Ar and Ph), 7.06 (d, J = 8.3 Hz, 1
H, Ar8or8Ј), 3.57 (dd, JHH = 15.3 Hz, JHP = 25.6 Hz, 1 H, CH2α),
3.32 (dd, JHH = 15.3 Hz, JHP = 7.8 Hz, 1 H, CH2β) ppm. 13C{1H}
(P)-(Sax)-4,5-Dihydro-4,4-diphenyl-3-oxa-4-silacyclohepta[2,1-a;3,4-
aЈ]dinaphthalene (9): A slurry of the red dilithium salt of 7 (0.29 g,
1.0 mmol), prepared according to method A, was cooled to –60 °C
and dichlorodiphenylsilane (0.44 mL, 2.1 mmol) was added. The
reaction mixture was stirred for 4 h while warming to ambient tem-
perature. The crude reaction mixture was filtered through a small
plug of silica and the product purified by column chromatography
(pentane/EtOAc, 9.5:0.5) to give 9 as a colourless solid (0.28 g,
0.6 mmol, 60%). Rf = 0.62. [α]2D5 = –37.7 (c = 1.00, CHCl3). M.p.
251–253 °C. 1H NMR (400.1 MHz, CDCl3): δ = 7.88 (approx. d, J
= 8.0 Hz, 2 H, 2ϫAr5or5Ј), 7.83 (d, J = 8.8 Hz, 1 H, Ar4or4Ј), 7.75
(d, J = 8.4 Hz, 1 H, Ar4or4Ј), 7.68–7.65 (m, 2 H, Pho), 7.51–7.33
(m, 6 H, Ar and Ph), 7.28 (d, J = 14 Hz, 1 H, Ar3or3Ј), 7.23–7.18
(m, 9 H, Ar and Ph), 2.93 (d, J = 14 Hz, 1 H, CH2α), 2.60 (d, J =
14 Hz, 1 H, CH2β) ppm. 13C{1H} NMR (100.6 MHz, CDCl3): δ =
150.8 (C–O, Ar), 134.8 (2 CH, Ph), 134.5 (2 CH, Ph), 133.7 (2 C,
Ar), 132.9 (2 C, Ar), 131.9 (C, Ar), 131.8 (C, Ar), 130.6 (CH, Ar),
130.4 (CH, Ar), 130.1 (2 C, Ar), 129.6 (CH, Ar), 128.1 (5 CH, Ph
and Ar), 127.9 (CH, Ar), 127.6 (2 CH, Ar), 126.8 (2 CH, Ar), 125.9
(CH, Ar), 125.7 (CH, Ar), 124.4 (CH, Ar), 124.0 (CH, Ar), 123.8
(C, Ar), 122.7 (CH, Ar), 22.8 (CH2) ppm. The Ar and Ph substitu-
2
(125.1 MHz, CDCl3) δ = 146.5 (d, JCP = 9.7 Hz, C, Ar2), 132.8
(d, JCP = 2.5 Hz, CH, Ar), 132.7 (C, Ar), 132.6 (C, Ar), 132.5 (C,
Ar), 132.3 (CH, Ar), 132.2 (CH, Ar), 131.5 (C, Ar), 130.9 (CH,
Ar), 130.5 (d, JCP C = 5.0 Hz, C, Ar), 130.2 (d, JCP = 10.1 Hz, C,
Ar), 129.0 (CH, Ar), 128.7 (d, 1JCP = 135.1 Hz, C, Phi), 128.4 (CH,
Ar), 128.3 (CH, Ar), 128.2 (d, JCP = 12.5 Hz, CH, Phm), 127.6 (d,
JCP = 5.0 Hz, CH, Php), 127.1 (d, JCP = 5.0 Hz, CH, Pho), 126.6
(CH, Ar), 126.4 (CH, Ar), 125.8 (CH, Ar), 125.5 (CH, Ar), 124.6,
1
122.2 (CH, Ar), 36.5 (d, JCP = 85.1 Hz, CH2) ppm. The Ar and
Ph substituents could not be easily distinguished. 31P{1H}
(202.4 MHz, CDCl ) δ = 53.51 ppm. IR (CCl solution): ν = 3059
˜
3
4
(CH, Ar), 2961 (CH2 Bz), 1252 (P=O), 1217 (P=O) cm–1. HRMS
(EI) found 406.1131, C27H19O2P required 406.1123.
Crystallographic Data: Colourless crystals of 2a were grown from
toluene, 5a, 7, 9, and 10 from CH2Cl2/hexane, 11a from CH2Cl2/
Et2O. All single crystals were attained by either liquid–liquid dif-
fusion techniques or by cooling to 4 °C. Single crystal diffraction
data was collected using graphite-monochromated Mo-Kα X-radia-
tion using either a Bruker APEX (2a, 5a, 9 and 10) or SMART1000
(7, 11a) CCD area detector diffractometer, each equipped with an
Oxford Cryostream cooling device. All data was collected at 150 K.
Details of the individual data collections and refinements are given
in Table 1. All structures were solved by direct methods using
SHELXS-97, except 5a which was solved using SIR-92. All struc-
tures were refined by least-squares full-matrix refinements against
F2 using SHELXL-97, and all non-H atoms were refined with an-
isotropic atomic displacement parameters (adps). Hydrogen atoms
were geometrically placed and included as part of a riding model
ents could not be easily distinguished. IR (CHCl3 solution): ν =
˜
2958 (Ar CH), 1125 (SiPh2), 984 (Si–O–Ar), 948 (Si–O–Ar) cm–1.
HRMS (EI) found 464.1596 required 464.1599. C33H24OSi
(464.16): calcd. C 85.31, H 5.21; found C 85.27, H 5.38.
6,7-Dihydro-6,6-diphenyl-5-oxa-6-siladibenzo[a,c]cycloheptene (10):
A slurry of the yellow-green dilithium salt of 8 (0.34 g, 1.8 mmol),
prepared according to method A, was cooled to –60 °C and dichlo-
rodiphenylsilane (0.80 mL, 3.78 mmol) was added. The reaction
mixture was stirred for 4 h while warming to ambient temperature.
The crude reaction mixture was filtered through a small plug of
silica and the product crystallised from CH2Cl2/pentane (1:5) to
Eur. J. Org. Chem. 2007, 1613–1623
© 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1621

M. Solinas, R. E. Meadows, C. Wilson, A. J. Blake, S. Woodward
FULL PAPER
Table 1. Summary of crystal data.
2a
5a
7
Chemical formula
Mr
Cell setting, space group
Temperature [K]
a, b, c [Å]
C27H20O4S·C7H8
532.62
orthorhombic, P212121
150(2)
7.4803(6), 17.8177(14),
19.953(2)
C28H19F3O6S2
572.55
monoclinic, P21
150(2)
10.1291(11), 9.3320(10),
14.1204(14)
C21H16O
284.34
tetragonal, P41
150(2)
8.9239(11), 8.9239(11),
37.956(9)
α, β, γ [°]
90.00, 90.00, 90.00
2659.4(4)
90.00, 99.242(2), 90.00
1317.4(4)
90.00, 90.00, 90.00
3023(2)
V [Å3]
Z
4
2
8
Dx [Mg·m–3]
1.330
0.16
1.443
0.27
1.250
0.08
µ [mm–1]
Crystal form, colour
Crystal size [mm]
Tmin, Tmax
column, colourless
0.64ϫ0.18ϫ0.15
–
trigonal tablet, colourless
0.77ϫ0.67ϫ0.08
0.440, 0.744
7285, 5312, 4909
tablet, colourless
0.53ϫ0.38ϫ0.11
–
No. of measured, independent and
observed [IϾ2σ(I)] reflections
Rint
16733, 6089, 5095
15176, 3150, 2658
0.049
0.042, 0.075, 0.96
0.001
0.25, –0.29
0.03(6)
0.033
0.038, 0.094, 1.00
0.001
0.35, –0.19
0.00(6)
0.044
0.034, 0.079, 1.10
0.001
R[F2 Ͼ 2σ(F2)], wR(F2), S
(∆/σ)max
∆ρmax, ∆ρmin [eÅ–3]
Flack parameter
0.15, –0.15
9
10
11a
Chemical formula
Mr
Cell setting, space group
Temperature [K]
a, b, c [Å]
C33H24OSi
464.61
monoclinic, P21
150(2)
9.4434(13), 11.0517(15),
11.7216(16)
90.00, 92.571(3), 90.00
1222.1(3)
C25H20OSi
364.50
monoclinic, P21/c
150(2)
15.5742(11), 18.9111(14),
12.9999(9)
90.00, 96.122(1), 90.00
3807.0(5)
C27H19O2P
406.39
orthorhombic, P212121
150(2)
10.2706(11), 10.7256(11),
18.393(2)
α, β, γ [°]
90.00, 90.00, 90.00
2026.2(6)
V [Å3]
Z
2
8
4
Dx [Mg·m–3]
1.263
0.12
1.272
0.14
1.332
0.16
µ [mm–1]
Crystal form, colour
Crystal size [mm]
Tmin, Tmax
plate, colourless
0.34ϫ0.24ϫ0.06
–
block, colourless
0.49ϫ0.48ϫ0.21
–
column, colourless
0.90ϫ0.20ϫ0.18
0.781, 1.000
15566, 4591, 4251
No. of measured, independent and
observed [IϾ2σ(I)] reflections
Rint
7546, 5160, 3954
22703, 8651, 6597
0.033
0.048, 0.098, 0.92
Ͻ0.0001
0.37, –0.24
0.22(13)
0.090
0.052, 0.147, 1.04
0.001
0.025
0.035, 0.095, 1.07
0.001
0.55, –0.25
0.02(7)
R[F2 Ͼ 2σ(F2)], wR(F2), S
(∆/σ)max
∆ρmax, ∆ρmin [eÅ–3]
Flack parameter
0.49, –0.33
except the Me hydrogen atoms in 2a and 5a and the hydroxy hydro-
gen atoms in 2a and 7, which were all located from difference Fou-
rier syntheses and refined as part of rigid rotating groups. The ab-
solute configuration has been determined in all cases and Flack
parameters are reported except for 7, which conatins no atoms
heavier than Si so a Flack parameter cannot be reliably determined
using Mo-Kα X-radiation and 10, which crystallises in a centrosym-
metric space group. Crystallographic data for all compounds are
summarised in Table 1.[28]
port. One of us (RM) is grateful to the EPSRC for partial support
of a studentship.
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Eur. J. Org. Chem. 2007, 1613–1623
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