Premium
Versatile Homoallylic Boronates by Chemo‐, S N 2′‐, Diastereo‐ and Enantioselective Catalytic Sequence of Cu−H Addition to Vinyl‐B(pin)/Allylic Substitution
Author(s) -
Lee Jaehee,
Torker Sebastian,
Hoveyda Amir H.
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201611444
Subject(s) - allylic rearrangement , enantioselective synthesis , diastereomer , chemistry , phosphine , stereoselectivity , catalysis , stereocenter , yield (engineering) , medicinal chemistry , carbene , organic chemistry , materials science , metallurgy
A highly chemo‐, diastereo‐ and enantioselective catalytic method that efficiently combines a silyl hydride, vinyl‐B(pin) (pin=pinacolato) and (E)‐1,2‐disubstituted allylic phosphates is introduced. Reactions, best promoted by a Cu‐based complex with a chiral sulfonate‐containing N‐heterocyclic carbene, are broadly applicable. Aryl‐, heteroaryl‐, alkenyl‐, alkynyl‐ and alkyl‐substituted allylic phosphates may thus be converted to the corresponding homoallylic boronates and then alcohols (after C−B bond oxidation) in 46–91 % yield and in up to >98 % S N 2′:S N 2 ratio, 96:4 diastereomeric ratio and 98:2 enantiomeric ratio. The reasons why an NHC−Cu catalyst is uniquely effective (vs. the corresponding phosphine systems) and the basis for different trends in stereoselectivity are provided with the aid of DFT calculations.