A structural and mechanistic investigation of the mono-O-phenylation of diols with BiPh3(OAc)2

Article abstract of DOI:10.1016/S0022-328X(02)01895-8

The mono-O-phenylation of enantiomerically pure pinanediol 2 using BiPh₃(OAc)₂ 1 and the biphenyl-2,2′-ylenephenylbismuth analogue 9 has been investigated. It is postulated that reductive elimination at the trigonal bipyramidal bismuth (V) centre of 1 upon exposure to ambient light affects the transfer of an apical phenyl ligand to the least sterically encumbered hydroxyl group of the diol, affording the monophenyl ether in good yield. SbPh₃(OAc)₂ fails to undergo reductive elimination, affording the stable diolate 6 instead. The X-ray crystal structure of 6 provides a reasonable model for the intermediate of the bismuth mono-O-phenylation, and suggests further studies with bismuth complexes such as 9 possessing intramolecularly tethered ligands incapable of facilitating the mono-O-phenylation reaction. The discussions are supported by X-ray crystallographic correlations, and calculations indicate that (M)-(-)-6 adopts the lowest energy conformational diastereoisomer.

Full text of DOI:10.1016/S0022-328X(02)01895-8

Journal of Organometallic Chemistry 662 (2002) 98Á104
/
www.elsevier.com/locate/jorganchem
A structural and mechanistic investigation of the mono-O-
phenylation of diols with BiPh3(OAc)2
Simon J. Coles a, James F. Costello b,*, Michael B. Hursthouse a, Stephen Smith b
a EPSRC National Crystallographic Service, Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
b Department of Chemistry, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK
Received 10 July 2002; accepted 22 August 2002
Abstract
The mono-O-phenylation of enantiomerically pure pinanediol 2 using BiPh3(OAc)2 1 and the biphenyl-2,2?-ylenephenylbismuth
analogue 9 has been investigated. It is postulated that reductive elimination at the trigonal bipyramidal bismuth (V) centre of 1 upon
exposure to ambient light affects the transfer of an apical phenyl ligand to the least sterically encumbered hydroxyl group of the diol,
affording the monophenyl ether in good yield. SbPh3(OAc)2 fails to undergo reductive elimination, affording the stable diolate 6
instead. The X-ray crystal structure of 6 provides a reasonable model for the intermediate of the bismuth mono-O-phenylation, and
suggests further studies with bismuth complexes such as 9 possessing intramolecularly tethered ligands incapable of facilitating the
mono-O-phenylation reaction. The discussions are supported by X-ray crystallographic correlations, and calculations indicate that
(M)-(ꢀ)-6 adopts the lowest energy conformational diastereoisomer.
/
# 2002 Elsevier Science B.V. All rights reserved.
Keywords: Mono-O-phenylation; Organobismuth; Propellers
1. Introduction
functionality such as an alkyl/aryl ether [4]. These
observations led David and Thieffry to propose that
O-phenylation is attended by a cyclic transition struc-
ture reminiscent of 7 (Fig. 1) [5], in which a trigonal
bipyramidal (TBPY) Bi(V) centre accommodates a
diolate species at the equatorial and axial coordination
sites; the least encumbered acceptor functionality occu-
pying the sterically undemanding equatorial co-ordina-
tion site. It was presumed that the relief of steric
pressure drives the transfer of the axial phenyl ligand
to the equatorial acceptor functionality. In an attempt
to probe the synthetic utility of the mono-O-phenylation
reaction, and to investigate the model proposed by
David and Thieffry, we present herein a mechanistic and
structural study as a contribution towards the under-
standing of photoredox processes of main group ele-
ments. We have recently demonstrated that inversion of
the propeller configuration [6] of co-ordinated PPh3 is a
major contributor to the switch of specific rotation in
chiral metal complexes [7]. We now report the first
example of a stereogenic XPh3 propeller unit incorpo-
rated within an enantiomerically pure TBPY dioxo
The photoredox processes associated with main group
metal complexes are relatively rare and as such remain a
neglected area of study. They are invariably initiated by
metal-centred or charge-transfer excited states which
lead to inter- and intramolecular reactions [1]. David
and Thieffry reported that refluxing CH2Cl2 (DCM)
solutions of 1,n-diols (nꢁ
/
2Á6) are selectively mono-O-
/
phenylated with BiPh3(OAc)2 (1) in good to excellent
yields [2]. O-Phenylation was invariably accompanied
by an induction period of up to 2 h, and in addition to
being solvent selective, photochemical activation was
required [3]. Although the rate of mono-O-phenylation
is found to decrease with increasing chain length (nꢁ
/
206), overall yields remained high. Excellent regios-
/
electivity was observed in the case of secondary versus
tertiary hydroxyl groups. The process of O-phenylation
was found to require the participation of an ancillary
* Corresponding author. Tel.: ꢂ
344-2904
E-mail address: james.costello@uwe.ac.uk (J.F. Costello).
/
44-117-344-2476; fax: ꢂ44-177-
/
0022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 8 9 5 - 8

S.J. Coles et al. / Journal of Organometallic Chemistry 662 (2002) 98Á
/
104
99
Fig. 1. Conditions, (a) DCM-d2, ambient light or 366 nm; (b) 2, DCM-d2, D; (c) 2, DCM-d2, ambient light, D.
chelate, and comment upon the implications for the
stereoisomerisation processes within such systems.
aryl radical species was readily investigated by the
addition of one and two equivalents of 1,1-dipheny-
lethylene, an efficient radical scavenger [9], to solutions
of 2 and 1 in refluxing DCM. After 4 h in strong
sunlight, 1H-NMR analyses of the crude mixtures
revealed the yield of 3 (ca. 70%) to be similar to that
of a control reaction. It was concluded therefore that
photo-generated aryl radical species do not play a
significant role in mono-O-phenylation.
NMR studies were carried out to examine the fate of 1
during the course of O-phenylation. A DCM-d2 solution
of 1 was irradiated for 1 h at 366 nm, producing a fine
white precipitate. NMR analysis revealed the appear-
2. Results
(ꢀ
)-Pinanediol 21 was chosen as the model substrate
for our studies as it possesses vicinal secondary/tertiary
/
hydroxyl groups; a combination expected to afford
3, Scheme 1). It is
complete regioselectivity (i.e. 20
/
cheap and readily available in both enantiomeric forms
and is therefore potentially amenable to stereochemical
investigations if necessary. The diol 2 and the (C-3)-O-
phenyl ether 3 may be readily distinguished from each
ance of additional resonances at dꢁ
/
8.45 (d), 7.88 (t)
1
dꢁ7.35 (s) and 1.92 (s) ppm. The low field singlet was
/
other in the crude reaction mixture by the H-NMR
resonance associated with the hydrogen atom geminal to
the acceptor (secondary) hydroxyl moiety [i.e. H-3 d
attributed to C6H6. The remaining resonances are
attributed to BiPh(OAc)2 8, which ultimately poly-
merises to afford an insoluble precipitate (Fig. 1a) [10].
An equimolar quantity of 1 was added to a DCM-d2
(CDCl3)ꢁ
1H-NMR spectrum of commercially available cis-pino-
nic acid2 5 (dH-3ꢁ
2.87 ppm), allows ready identifica-
/3.94 (2) and 4.54 (3) ppm]. Furthermore, the
solution of (ꢀ)-2, and the mixture was monitored via
/
/
1H-NMR at room temperature in the absence of light
for 12 h. O-Phenylation was not observed. The product
of glycol cleavage 4 was however noted almost imme-
diately, accompanied by the formation of BiPh3 (Fig.
1b). Irradiation (366 nm) of the crude reaction mixture
after 12 h afforded the mono-O-phenylated material 3
(22%). The crude reaction mixture attending the mono-
tion of aldehyde 4, the product of glycol cleavage [8].
In a typical procedure, equimolar quantities of 1 and
(ꢀ
/
)-2 were refluxed in DCM for 2 h, affording 3 (79%)
)-2 (8%). Under particu-
and 4 (13%) and unreacted (ꢀ
/
larly bright ambient conditions, synthetically useful
yields of 3 (66%) were produced after only 10 min,
accompanied by small amounts of 4 (8%) and unreacted
starting material (ꢀ
light levels afforded yields of 3 in the range 2Á
after 5 h, with glycol cleavage being the significant
/
)-2 (26%). However, low natural
O-phenylation of 2 with 1 in DCM-d2 contains*
varying degrees depending upon the reaction con-
ditions*3, 8, 4, C6H6 and BiPh3, in addition to a fine
white precipitate (Fig. 1c). In the absence of strong light,
oxidation of the substrate predominates with the con-
comitant formation of BiPh3. The formation of Bi-
Ph(OAc)2 8 would appear to accompany both the light
/
in
/
8% even
/
process (36Á
/
49%). The participation of photo-generated
1
2
[1R-(1a,2a,3a,5a)]-2,6,6-Trimethylbicyclo[3.1.1]heptane-2,3-diol.
cis-3-Acetyl-2,2-dimethylcyclobutaneacetic acid.

100
S.J. Coles et al. / Journal of Organometallic Chemistry 662 (2002) 98Á104
/
Scheme 1. Reagents: (i) 1, D, light, DCM; (ii) 1, D, DCM, and (iii) SbPh3(OAc)2, TMG, DCM.
induced decomposition of 1, and the mono-O-phenyla-
tion of 2.
A DCM-d2 solution of (ꢀ)-2 was treated with one
/
equivalent of SbPh3(OAc)2 under varying levels of
natural light and refluxed for 4 h. Neither substrate
oxidation nor mono-O-phenylation were observed via
1H-NMR spectroscopy. However, an alternative pro-
duct, characterised as 6 [11] (Scheme 1) was detected
upon initial mixing, the concentration of which re-
mained unchanged after 4 h reflux (40%). The addition
of TMG increased the concentration of 6 to 87%. This
represents the most expeditious route to 6 reported to
date. Irradiation of the crude reaction mixture (366 and
254 nm) failed to initiate mono-O-phenylation. Single
crystals of 6 were grown from a dichloromethane
solution layered with hexane. The molecular structure
of 6 is presented in Fig. 2 together with the atomic
numbering scheme, whilst selected bond lengths and
angles are presented in Table 1. The complex possesses a
distorted TBPY molecular geometry about the metal
centre, where O(1) of the diolate and C(23) occupy the
axial and O(2)/C(11)/C(17) occupy the equatorial co-
ordination sites.
Fig. 2. The X-ray crystal structure of (ꢀ)-(M)-6.
/
Like 1, phenylbiphenyl-2,2?-ylenebismuth diacetate 9
(Fig. 3) reacts with a variety of nucleophiles to afford
good yields of C-phenylated substrates [12]. Equimolar
3. Discussion
quantities of 9 and (ꢀ)-2 were refluxed in DCM in
/
In an analogous fashion to the transition metals, main
group elements have been classified according to the
electronic configuration of the ground state. Thus, Bi(V)
and Sb(V) complexes possessing empty valence shells
(i.e. ns0np0) are classified as s0. Consequently, the only
electronic transitions available to s0 complexes are the
ligand to metal charge transfer (LMCT) type. Although
few examples have been reported [13], reductive elim-
ination appears to be the characteristic photoreaction of
strong ambient light. After three attempts, only trace
amounts of the O-phenyl ether 3 could be observed after
4 h reflux. On each occasion, the product was 4, that of
glycol cleavage (60%, 0.6 h). In our hands, both cis- and
trans-cyclohexane-1,2-diols are smoothly transformed
to the corresponding O-phenyl ethers using 1 in
excellent yields (ꢀ90%). The analogous bismuth com-
/
plex 9 fails to affect the corresponding transformation
after 4 h reflux.

S.J. Coles et al. / Journal of Organometallic Chemistry 662 (2002) 98Á
/
104
101
Table 1
chelates within distorted [15] SP structures (Xꢁ
/
P [16],
˚
Selected bond lengths (A) and angles (8) for 6
Sb [17], Sn [18]) invariably span the basal edge, whereas
the corresponding chelate within TBPY systems occupy
the axial (Oax) and equatorial (Oeq) sites [19]. This and
previous studies [20] clearly demonstrate that the more
crowded oxygen atom of a non-symmetrical dioxo
chelate occupies the least crowded axial co-ordination
site (Oax) of a TBPY arrangement. The observed
regioselectivity of mono-O-phenylation is therefore
conveniently accounted for by invoking a transition
state resembling a TBPY arrangement such as 7.
Bond lengths
C11ÃSb
C17ÃSb1
C23ÃSb1
O1ÃSb1
O2ÃSb1
12.118(3)
2.143(3)
2.161(3)
2.008(2)
1.989(2)
Bond angles
O2ÃSb1ÃO1
O2ÃSb1ÃC11
O2ÃSb1ÃC17
O2ÃSb1ÃC23
O1ÃSb1ÃC23
80.11(9)
113.09(11)
136.78(10)
84.86(10)
162.81(11)
When two or more aryl rings are bonded to a central
atom X (i.e. the SbPh3 unit of 6 for example) rotation
about a given XÃ/Ci bond is coupled in the sense that no
ring moves independently of the other two [21]. Aryl
rings within such systems afford a correlated arrange-
ment which may be described in terms of two enantio-
meric propeller configurations, i.e. clockwise (P) and
anti-clockwise (M), respectively [22]. These conforma-
tional alternatives are illustrated for the proposed
reactive intermediate 7 (Newman projections, Fig. 4).
s0 metal complexes. Our interest in SbPh3(OAc)2 as a
potential reagent for mono-O-phenylation was stimu-
lated by the observation that electronic excitation of the
s0 complex [Sb(V)Cl6]ꢀ [14] is attended by an efficient
two electron reduction of the metal affording Cl2.
However unlike 1, SbPh3(OAc)2 forms the stable diolate
complex 6 which fails to undergo reductive elimination
even when irradiated. In contrast with the d0 configura-
tion of transition metals, the oxidation strength of s0
complexes decreases down the group, as does the energy
of the LMCT transitions. The variation in photo-
reactivity between the antimony and bismuth complexes
is therefore a reflection of the relative energies of LMCT
transitions.
Further analysis of the X-ray crystal structure of
antimony complex 6 is warranted for two reasons,
namely; (i) it constitutes the first example of a stereo-
genic XPh3 moiety incorporated within an enantiomeri-
cally pure bidentate dioxo-ligand, and (ii) it is a
reasonable model for 7, the proposed transition-state
for the mono-O-phenylation of 2 with 1 (Fig. 1).
A search of the Cambridge structural database (CSD
refcodes supplied in reference section) for five co-
ordinate systems analogous to 6, possessing an integral
A high energy achiral arrangement*
the transition-state for the one ring-flip stereoisomerisa-
tion process*is also observed in the solid state [19].
/
which resembles
/
Assuming that the conformations adopted in the solid-
state represent favoured arrangements on the potential
energy surface of a complex, the observation of achiral
and chiral arrangements indicate a low energy stereo-
isomerisation pathway for Pl
/
M via the achiral struc-
ture. The X-ray crystal structure of (ꢀ
/)-6 adopts the
(M) propeller configuration, and therefore constitutes a
favoured arrangement on the potential energy surface of
the stereoisomerisation pathway Pl/M. When the metal
centre is co-ordinated to an achiral dioxo-chelate, the
propeller conformers are degenerate and as such are
expected to occur randomly. However, as in the case of
6 where the dioxo-chelate is chiral, the propeller
conformers are rendered diastereoisomeric and as such
are not expected to occur in equal amounts. The X-ray
crystal structure of (M)-(ꢀ)-6, which constitutes the
/
first example of a XPh3 moiety incorporated within an
enantiomerically pure bidentate ligand, is expected to be
lower in energy than the corresponding conformational
triphenyl unit XPh3 (Xꢁcentral atom) and a five-
/
membered dioxo-chelating ligand reveals examples of
both SP and TBPY arrangements (Fig. 3). Dioxo
diastereoisomer (P)-(ꢀ)-6. Single point energy calcula-
/
Fig. 3. Structural alternatives for a penta co-ordinate metal possessing an integral triaryl unit and a five-membered dioxo-chelate.

102
S.J. Coles et al. / Journal of Organometallic Chemistry 662 (2002) 98Á104
/
Fig. 4. The low energy stereoisomerisation pathway for (P)l(M) via the higher energy achiral arrangement.
/
tions3 upon the optimised structure (M)-(ꢀ
corresponding conformational diastereoisomer (P)-(ꢀ
/
)-6, and the
the event of complex 9 forming a spiro TBPY diolate
species reminiscent of 7 (Fig. 1), ligand transfer of axial
PhA would prove impossible.
A search of the CSD for five co-ordinate spiro group
V complexes possessing both a 2,2?-biphenyl and
another bidentate ligand revealed three structural alter-
/)-
6 indicate a significant preference for the former (DEꢁ
/
30 kJ molꢀ1).4 This preference may be readily appre-
ciated by considering Newman projections of the con-
formational diastereoisomers (M)-(ꢀ
/
)-, and (P)-(ꢀ
/
)-6
natives 10Á
TBPY systems of type 10 are observed, in which the
bidentate ligands occupy the axialÁequatorial co-ordi-
nation sites with the mono-dentate ligand occupying the
remaining equatorial site {P (V); XꢁPh, Me [23], a-
napthyl [24], thienyl [25]), and Sb (V); Xꢁtolyl [26]}.
This arrangement clearly represents a structural pre-
cedent for an axially tethered PhA ligand. Two examples
of SP co-ordination geometries are reported, both of
which are based upon P (V). Here, a monodentate
phenyl ligand occupies either an equatorial (11 [27]) or
axial (12 [28]) co-ordination site. As discussed pre-
viously, regiochemical observations support a TBPY
transition-state. As expected, and in contrast with
BiPh3(OAc)2 1, phenylbiphenyl-2,2?-ylenebismuth dia-
/
12 (Fig. 6). Several P (V) and Sb (V) based
(Fig. 5). Complex 6 adopts the (M)-(ꢀ
/
)-conformational
diastereoisomer in the solid-state, thereby orienting the
bridgehead methyl moiety (C10) of the pinane fragment
above the face of phenyl ring B. The epimeric con-
/
/
formational diastereoisomer (P)-(ꢀ)- orients the corre-
/
/
sponding methyl moiety (C10) above the sterically
demanding edge of phenyl ring B, thereby generating a
clashing interaction.
In accord with the model of David and Thieffry, the
X-ray crystal structure of 6 strongly suggests that the
axial phenyl ligand PhA of the TBPY arrangement
couples with the neighbouring acceptor functionality
of the co-ordinated diol (i.e. PhA0
/
Oeq, Fig. 3). This
possibility is supported by the fact that PhA possesses
˚
2.16 A;
the weakest MÃ
/
Ci bond [i.e. SbÃ
/
PhA (C23)ꢁ
/
˚
˚
SbÃPhB (C11)ꢁ
/
/
2.12 A and SbÃ
/
PhC (C17)ꢁ2.14 A,
/
cetate 9 (Fig. 3) failed to mono-O-phenylate (ꢀ)-2 or
/
Table 1]. The proposition was examined by covalently
tethering PhA to a neighbouring phenyl ligand, in an
attempt to prevent reductive elimination. This was
achieved by attempting the mono-O-phenylation of 2
with the bidentate 2,2?-biphenyl analogue 9 (Fig. 3). In
cis/trans-cyclohexane-1,2-diols. This is entirely consis-
tent with the formation of a transition structure of type
10, in which the favoured axial phenyl ligand is
prevented from undergoing a reductive elimination
because of a covalent tether.
In conclusion, reductive elimination of 1 upon ex-
posure to strong ambient light results in the mono-O-
phenylation of (ꢀ
reduction to 8 or (b) reduction to BiPh3 with concomi-
tant oxidation of (ꢀ)-2 to 4. Structural studies support
/)-2 at a faster rate than, (a) photo-
/
the model of David and Thieffry, which proposes that a
dioxo TBPY transition structure reminiscent of 7 under-
goes reductive elimination of an axial phenyl ligand.
Finally, antimony complex 6, a model for the dioxo
Fig. 5. The conformational diastereoisomers (P)-(ꢀ
/
)-6 and (M)-(ꢀ)-
/
6.
3
HartreeÁFock at the 3-21G(*) level using PC Spartan Pro (1.0.5).
/
Designed and distributed by Wavefunction, Inc., 18401 Von Karman,
Suite 370, Irvine, CA 92612, USA.
4
The 3-21G(*) basis set is particularly appropriate for organic
molecules incorporating main group elements such as phosphorus. For
simplicity therefore, the antimony atom within the structure of 6 was
replaced by phosphorous, and DE should be viewed as an upper limit.
Fig. 6. X-ray crystallographically determined alternatives for spiro
Group V complexes 10Á12.
/

S.J. Coles et al. / Journal of Organometallic Chemistry 662 (2002) 98Á
/
104
103
0.752 e Aꢀ3. Data were
0.20ꢃ0.10 mm
˚
TBPY transition structure 7, constitutes the first exam-
ple of an enantiopure complex incorporating a stereo-
genic XPh3 propeller moiety. The complex adopts the
densities were 0.875 and ꢀ
/
collected using a crystal of size 0.28ꢃ
on an Enraf Nonius Kappa CCD area detector diffract-
ometer at the window of a rotating anode FR591
/
/
energetically favoured (M)-(ꢀ) conformational diaster-
/
eoisomer, which constitutes the lowest energy arrange-
ment on the potential energy profile of the complex.
generator, with a molybdenum target [l(MoÁK )
ꢁ
/
a
˚
0.71069 A] and controlled by the Collect [29] software
package. Images of 28 thickness and 10 s exposure were
taken for a combined phi and omega scan strategy, with
a detector to crystal distance of 30 mm (theta offsets
between 3.9 and 6.28) and processed by DENZO [30].
Data were corrected for absorption using the semi-
empirical method employed in SORTAV [31]. The struc-
ture was solved by direct methods (SHELXS-97 [32]) and
then subjected to full-matrix least-squares refinement
4. Experimental
4.1. General procedures
All reactions were performed under an atmosphere of
dry nitrogen. CH2Cl2 was distilled under an atmosphere
of nitrogen from CaH2. H-NMR were recorded on a
based on F2o
(SHELXL-97 [32]). Non-hydrogen atoms
were refined anisotropically with hydrogens included in
1
JEOL JNM 300 (300 MHz) spectrometer, using CDCl3
or CD2Cl2 as solvents, and referenced to residual CHCl3
or CH2Cl2, with chemical shifts being reported at d
(ppm) from Me4Si. 13C-NMR were recorded on JEOL
JNM 300 (75 MHz) spectrometer using CDCl3. UV
˚
H distanceꢁ0.97 A) with ther-
idealised positions (CÃ
mal parameters riding on those of the parent atom. The
weighting scheme used was wꢁ
1/[s2(F2o)].
/
/
/
analyses were conducted on a PerkinÁElmer Lambda 40
spectrophotometer. Elemental analyses were conducted
by the University of Warwick analytical services.
/
4.4. Data retrieval
Crystal structures were located within version 5.21
(April 2001 release) of the Cambridge Structural Data-
base (CSD) which contained 233 218 entries using the
QUEST program [33].
4.2. Preparations
4.2.1. (1R,2R,3S,5R)-3-Phenoxypinane-2-ol (3)
In bright sunlight, 1.1 equivalents of BiPh3(OAc)2 was
added portionwise to a rapidly stirred solution of
pinanediol in CH2Cl2 (0.2 M) under an atmosphere of
N2. After 1 h the heterogeneous solution was filtered,
concentrated in vacuo and purified (SiO2/CHCl3) to
afford a clear oil characterised as 3 (79%). Anal. Calc.
for C16H22O2: C, 78.1; H, 8.9. Found: C, 78.0; H, 8.7%.
1H-NMR (300 MHz, CDCl3, 298 K): 7.30 (2H, m,. o-
H), 6.97 (3H, m, m/p-H), 4.54 (1H, q, H-3), 3.68 (1H, s,
OH), 2.56 (1H, m, H-4), 2.26 (1H, m, H-7), 2.07 (1H, t,
H-1), 1.98 (1H, m, H-5), 1.80 (1H, dq, H-4), 1.64 (1H, t,
H-7), 1.34 (3H, s, Me-9), 1.31 (3H, s, Me-10), 1.02 (3H,
s, Me-8). 13C-NMR (100 MHz, CDCl3, 298 K): 157.6 (i-
C), 129.7 (o-C), 121.7 (m-C), 116.3 (p-C), 75.9 (C-3),
73.8 (C-2), 53.8 (C-1), 40.5 (C-5), 38.5 (C-6), 35.6 (C-4),
30.7 (C-9), 28.4 (C-7), 28.0 (C-10), 24.5 (C-8).
5. Supplementary material
Crystallographic data for the structural analysis of 6
have been deposited with the Cambridge Crystallo-
graphic Data Centre, CCDC no. 189161. Copies of
this information may be obtained free of charge from
The Director, CCDC, 12 Union Road, Cambridge CB2
1EZ, UK (Fax: ꢂ44-1223-336033; e-mail: deposit@
/
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
Acknowledgements
We thank The Leverhulme Trust and the EPSRC for
financial support and for funding the X-ray crystal-
lographic facilities. We are particularly grateful to
Professor J.-P. Finet, for a sample of bismuth complex 9.
4.3. Structural characterisation of 6
C28H31O2Sb, Mrꢁ
/
260.64, orthorhombic, space
11.1720(2), cꢁ
120(2) K, Zꢁ8,
1064, 15 037 reflec-
27.468 (index ranges;
13 to 14 and lꢁ 33 to 33), which
merged to give 5239 unique reflections (Rint 0.0473) to
refine against 284 parameters. Final R indices were
wR2ꢁ0.0566 and R1ꢁ
0.0285 [F2ꢀ2s(F2)] and 0.0353
and 0.0597, respectively, for all data. Residual electron
group P212121, aꢁ8. 3694(2), bꢁ
/
/
/
3
˚
˚
25.7117(6) A, Uꢁ
m(MoÁKa)ꢁ
1.365 mmꢀ1, F(000)ꢁ
tions were collected, u range 1.99Á
hꢁ 9 to 10, kꢁ
/
2404.12(9) A , Tꢁ
/
/
/
/
/
References
/
[1] A. Vogler, A. Paukner, H. Kunkely, Coord. Chem. Rev. 97 (1990)
285.
/
ꢀ
/
/
ꢀ
/
/
ꢀ
/
ꢁ
/
[2] S. David, A. Thieffry, Tetrahedron Lett. 22 (1981) 5063.
[3] These restrictions may be obviated by Cu(II) catalysis; see V.A.
Dodonov, A.V. Gushchin, T.G. Brilkina, Zh. Obshch. Khim. 54
(1984) 2157, and R.A. Abramovittch, D.H.R. Barton, J.-P. Finet,
/
/
/

104
S.J. Coles et al. / Journal of Organometallic Chemistry 662 (2002) 98Á104
/
Tetrahedron 44 (1988) 3039. A plausible mechanism involves
oxidative addition of both Ph and OAc to the Cu (I) diolate
complex, followed by reductive transfer of the Ph to the hydroxyl
function.
[19] (a) N.S. Weng, V.G.K. Das Malays, J. Sci. Ser. B 16 (1995) 85
(RABZOJ);
(b) R.R. Holmes, R.O. Day, V. Chandrasekhar, J.M. Holmes,
Inorg. Chem. 26 (1987) 157 (FAZSUU);
[4] D.H.R. Barton, J.-P. Finet, C. Pichon, J. Chem. Soc. Chem.
Commun. (1986) 65.
(c) P.G. Harrison, T.J. King, J. Chem. Soc. Dalton Trans. (1974)
2298 (TPSNBH10);
[5] S. David, A. Thieffry, J. Org. Chem. 48 (1983) 441.
[6] (a) J.F. Costello, S.G. Davies, J. Chem. Soc. Perkin Trans. 2
(1998) 1683;
(d) J. Bordner, G.O. Doak, T.S. Everett, J. Am. Chem. Soc. 108
(1986) 4206 (DUGFIU).
[20] H. Barucki, S.J. Coles, J.F. Costello, T. Gelbrich, M.B. Hurst-
house, J. Organomet. Chem. 622 (2001) 265.
(b) J.F. Costello, S.G. Davies, D. McNally, J. Chem. Soc. Perkin
Trans. 2 (1999) 465.
[21] (a) R.J. Kurland, I.I. Schuster, A.K. Colter, J. Am. Chem. Soc. 87
(1965) 2279;
[7] A.P. Ayscough, J.F. Costello, S.G. Davies, Tetrahedron Asym-
metry 12 (2001) 1621.
(b) K. Mislow, Acc. Chem. Res. 9 (1976) 26;
[8] The cleavage of diols with BiPh3CO3 has been reported pre-
viously, see D.H.R. Barton, J.-P. Finet, W.B. Motherwell, C.
Pichon, Tetrahedron 42 (1986) 5627.
(c) D. Gust, K. Mislow, J. Am. Chem. Soc. 95 (1973) 1535.
[22] R.S. Cahn, C. Ingold, V. Prelog, Angew. Chem. Int. Ed. Engl. 5
(1966) 385.
[9] S. Combes, J.-P. Finet, Tetrahedron 55 (1999) 3377.
[10] G.B. Deacon, W.R. Jackson, J.M. Pfeiffer, Aust. J. Chem. 37
(1984) 527.
[23] R.O. Day, S. Husebye, R.R. Holmes, Inorg. Chem. 19 (1980)
3616 (MPHLPB, MPHLPA).
[24] R.O. Day, R.R. Holmes, Inorg. Chem. 19 (1980) 3609 (NPHPSA,
NPHPSB).
[11] K. Akiba, H. Fujishima, A. Ohtani, S. Kojima, Y. Yamamoto,
Bull. Soc. Chim. Belg. 106 (1997) 577.
[25] D.W. Allen, L.A. March, I.W. Nowell, J.C. Tebby, Z. Natur-
forsch. Teil B 38 (1983) 465 (BUFMEU).
[12] A.Y. Fedorov, J.-P. Finet, J. Chem. Soc. Perkin Trans. (2000)
3775.
[26] K. Akiba, H. Fujishima, A. Ohtani, S. Kojima, Y. Yamamoto,
Bull. Soc. Chim. Belg. 106 (1997) 577 (NUYNOK).
[27] G. Wax, R. Haller, H.B. Stegman, K. Scheffler, T. Buttes, W.
Winter, Chem. Ber. 116 (1983) 1914 (BUMBOA).
[28] R.R. Holmes, R.O. Day, V. Chandraskar, J.M. Holmes, Inorg.
Chem. 26 (1987) 157 (FAZTAB).
[13] (a) H. Nikol, A. Vogler, Pure Appl. Chem. 64 (1992) 1311;
(b) A. Vogler, C. Quett, A. Paukner, H. Kunkely, J. Am. Chem.
Soc. 109 (1986) 8263;
(c) A. Paukner, H. Kunkely, A. Vogler, in: H. Yersin, A. Vogler
(Eds.), Photochemistry and Photophysics of Co-ordination Com-
pounds, Springer, Berlin, 1987, p. 205.
[29] R. Hooft, Collect: Data Collection Software, B.V. Nonius, 1998.
[30] Z. Otwinowski, W. Minor, in: C.W. Carter Jr., R.M. Sweet (Eds.),
Methods in Enzymology: Macromolecular Crystallography, Part
A, 276 (1997) 307, Academic Press.
[14] A. Vogler, A. Paukner, Inorg. Chim. Acta 163 (1989) 207.
[15] E.L. Muetterties, L.J. Guggenberger, J. Am. Chem. Soc. 96 (1974)
1748.
[16] T.J. Chow, L.-P. Li, Y.R. Lee, K.-J. Lin, C.-Y. Chen, J. Chem.
Soc. Perkin Trans. 2 (1996) 2681 (RAYSIT).
[17] (a) M.J. Hall, D.B. Sowerby, J. Am. Chem. Soc. 102 (1980) 628
(PCATSB);
[31] (a) R.H. Blessing, Acta Crystallogr. Sect. A 51 (1995) 33;
(b) R.H. Blessing, J. Appl. Crystallogr. 30 (1997) 421.
[32] G.M. Sheldrick, SHELX-97, Programs for Crystal Structure
Solution and Refinement, University of Gottingen, Gottingen,
¨ ¨
(b) R.R. Holmes, R.O. Day, V. Chandrasekhar, J.M. Holmes,
Inorg. Chem. 26 (1987) 163 (FAZVIL).
Germany, 1997.
[33] D.A. Fletcher, R.F. McMeeking, D. Parkin, J. Chem. Inf.
Comput. Sci. 36 (1996) 746.
[18] S.W. Ng, J.M. Houk, Acta Crystallogr. Sect. C 55 (1999) 310
(GODFIO).