Stereoselective addition of organomanganese reagents to chiral acylsilanes and aldehydes

Autor: Silvia Carini, Gérard Cahiez, Alfredo Ricci, Salvatore Pollicino, Mauro Comes-Franchini, Vanda Cerè, Paul Knochel, Celine Boucley
Rok vydání: 2001
Předmět:
Zdroj: Journal of Organometallic Chemistry. 624:223-228
ISSN: 0022-328X
DOI: 10.1016/s0022-328x(00)00902-5
Popis: Organomanganese halides and organomanganates prepared by transmetalation of organolithium and Grignard reagents add smoothly to the carbonyl moiety of acylsilanes and of substituted aldehydes bearing a chiral center at the a-position affording the desired alcohols in good to excellent yields and with essentially no undesired products from enolization. Comparison of the stereochemical outcome with that observed for other organometallic species, outlines the capability of organomanganese reagents to induce uniformly good diastereoselectivities, in a number of cases significantly higher than reported previously for these reactions. The key role displayed by the R3Si group in promoting high 1,2-asymmetric induction, clearly emerges in the comparison of acylsilane 12 with the corresponding aldehyde 13. The sense of the Cram:anti-Cram selectivity depends upon the nature of the carbonyl reagents engaged in these reactions. © 2001 Elsevier Science B.V. All rights reserved.
Databáze: OpenAIRE