The reactions between the stable (phosphanyl)(silyl)carbene 1 and different aliphatic aldehydes have been investigated for the first time. Results reveal that two competitive processes take place. The kinetically most favorable one is a concerted [2+1] cycloaddition to carbonyl leading to oxiranes as single diastereomers, with the trans arrangement of the alkyl and phosphoranyl groups, as the major products. Simultaneously, a [2+2]-like addition provides short-lived oxaphosphetene intermediates that rapidly evolve to the corresponding olefins with E stereochemistry, which are the thermodynamically most stable compounds. DFT calculations establish the mechanism for both processes and a rationale for the observed diastereoselectivity. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
|Journal||European Journal of Organic Chemistry|
|Publication status||Published - 11 Aug 2003|
Illa, O., Gornitzka, H., Branchadell, V., Baceiredo, A., Bertrand, G., & Ortuño, R. M. (2003). Reactions of a stable (phosphanyl)(silyl)carbene with aliphatic aldehydes: [2+1] versus [2+2] addition to a carbonyl group. European Journal of Organic Chemistry, (16), 3147-3152. https://doi.org/10.1002/ejoc.200300226