Premium
Forming Stereogenic Centers in Acyclic Systems from Alkynes
Author(s) -
Vabre Roxane,
Island Biana,
Diehl Claudia J.,
Schreiner Peter R.,
Marek Ilan
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201504756
Subject(s) - stereocenter , chemistry , substituent , aldehyde , heteroatom , residue (chemistry) , transition metal , stereochemistry , chelation , combinatorial chemistry , organic chemistry , enantioselective synthesis , catalysis , ring (chemistry)
The combined carbometalation/zinc homologation followed by reactions with α‐heterosubstituted aldehydes and imines proceed through a chair‐like transition structure with the substituent of the incoming aldehyde residue preferentially occupying a pseudo‐axial position to avoid the two gauche interactions. The heteroatom in the axial position produces a chelated intermediate (and not a Cornforth–Evans transition structure for α‐chloro aldehydes and imines) leading to a face differentiation in the allylation reaction. This method provides access to functionalized products in which three new carbon–carbon bonds and two to three stereogenic centers, including a quaternary one, were created in acyclic systems in a single‐pot operation from simple alkynes.