H-bonding as a control element in stereoselective Ru-catalyzed olefin metathesis.
H-bonding interactions have been exploited extensively in the design of catalysts for stereoselective synthesis but have rarely been utilized in the development of metal-catalyzed processes. Studies described herein demonstrate that intramolecular H-bonding interactions can significantly increase the rate and levels of stereochemical control in Ru-catalyzed olefin metathesis reactions. The utility of H-bonding in catalytic olefin metathesis is elucidated through development of exceptionally facile and highly diastereoselective ring-opening/cross-metathesis (DROCM) reactions, involving achiral Ru catalysts and enantiomerically enriched allylic alcohols. Transformations proceed to completion readily (> 98% conversion, up to 87% yield), often within minutes, in the presence of < or = 2 mol % of an achiral catalyst to afford synthetically versatile products of high stereochemical purity (up to > 98:2 dr and 11:1 E:Z).
Hoveyda
Amir H
AH
Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA. amir.hoveyda@bc.edu
Lombardi
Pamela J
PJ
O'Brien
Robert V
RV
Zhugralin
Adil R
AR