Catalytic Enantioselective Tandem Carbonyl Ylide Formation-Cycloaddition
摘要:
Catalytic enantioselective tandem carbonyl ylide formation-cycloaddition of alpha-diazo-beta-ketoesters 1 (R = alkyl, n = 1,2) using 1 mol% [Rh-2(S-DOSP)(4)] 2 in hexane at room temperature to give the cycloadducts 3 in good yields and up to 53% ee are described. (C) 1997 Elsevier Science Ltd.
Oxapolycycles from One-Pot Cross-Metathesis/Carbonyl Ylide Formation-Intramolecular Cycloaddition of α-Diazo-β-keto Esters
作者:David M. Hodgson、Deepshikha Angrish
DOI:10.1002/adsc.200600306
日期:2006.11
Chemoselective cross-metathesis of unsaturated α-diazo-β-ketoesters using Grubbs’ 2nd generation catalyst, followed by Rh2(OAc)4-catalysed tandem carbonylylideformation-intramolecularcycloaddition is demonstrated. The two different catalytic metallocarbene transfer reactions have also been successfully carried out in a one-pot procedure, which allows rapid generation of molecular complexity in
The Scope of Catalytic Enantioselective Tandem Carbonyl Ylide Formation−Intramolecular [3 + 2] Cycloadditions
作者:David M. Hodgson、Agnès H. Labande、Françoise Y. T. M. Pierard、María Á. Expósito Castro
DOI:10.1021/jo0343735
日期:2003.8.1
Catalytic enantioselective tandem carbonyl ylide formation-intramolecular 1,3-dipolar cycloaddition reactions of 2-diazo-3,6-diketoesters show promising scope in terms of asymmetric induction as the tethered alkene/alkyne dipolarophile component is varied. Cycloadditions were found to occur in moderate to very good yields, with a difference in ee exhibited by the electronically different 2-diazo-3,6-diketoesters 1, 25 and 33, 34. Values for ee of up to 90% for alkene dipolarophiles and up to 86% for alkyne dipolarophiles were obtained.