Mechanistic Dichotomy in the Asymmetric Allylation of Aldehydes with Allyltrichlorosilanes Catalyzed by Chiral Pyridine N-Oxides
Artikel i vetenskaplig tidskrift, 2013

Detailed kinetic and computational investigation of the enantio- and diastereoselective allylation of aldehydes 1 with allyltrichlorosilanes 5, employing the pyridine N-oxides METHOX (9) and QUINOX (10) as chiral organocatalysts, indicate that the reaction can proceed through a dissociative (cationic) or associative (neutral) mechanism: METHOX apparently favors a pentacoordinate cationic transition state, while the less sterically demanding QUINOX is likely to operate via a hexacoordinate neutral complex. In both pathways, only one molecule of the catalyst is involved in the rate- and selectivity-determining step, which is supported by both experimental and computational data.

allylsilanes

pyridine N-oxides

calculations

organocatalysis

allylation

Författare

Andrei V. Malkov

University of Glasgow

Loughborough University

Sigitas Stoncius

University of Glasgow

Vilniaus universitetas

Mark Bell

University of Dundee

University of Glasgow

Fabiomassimo Castelluzzo

University of Glasgow

Bayer SpA, Italy

Pedro Ramirez-Lopez

Universidad de Sevilla

University of Glasgow

Lada Biedermannova

University of Glasgow

Czech Academy of Sciences

Vratislav Langer

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Lubomir Rulisek

Czech Academy of Sciences

Pavel Kocovsky

Arrhenius Laboratory

University of Glasgow

Chemistry - A European Journal

0947-6539 (ISSN) 1521-3765 (eISSN)

Vol. 19 9167-9185

Ämneskategorier

Kemi

DOI

10.1002/chem.201203817