Premium
A [Pd (η 3 ‐PhCHCHCHPh)(phosphino‐oxazoline)] + complex with almost identical P‐ and N‐ trans influences. 13 C chemical shifts and allylic alkylation chemistry
Author(s) -
Dotta Pascal,
Anil Kumar P. G.,
Pregosin Paul S.
Publication year - 2002
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1075
Subject(s) - chemistry , diastereomer , chemical shift , allylic rearrangement , tsuji–trost reaction , oxazoline , enantioselective synthesis , alkylation , enantiomer , stereochemistry , cis–trans isomerism , nuclear magnetic resonance spectroscopy , medicinal chemistry , organic chemistry , catalysis
The Pd‐catalysed enantioselective allylic alkylation of a 1,3‐diphenylallyl substrate using a bulky phosphinooxazoline auxiliary leads to a relatively small enantiomeric excess of 66%. The ca 30% loss, relative to related P,N‐auxiliaries, is rationalized by (a) the presence of additional isomers, (b) a dynamic equilibrium between two of these as shown by exchange spectroscopy and (c) the identification of one exchanging diastereomer in which there is almost no difference between the two terminal allyl 13 C chemical shifts, i.e. these P‐ and N‐donors reveal an almost identical trans influence. Copyright © 2002 John Wiley & Sons, Ltd.