Catalytic Three-Component Domino Reaction for the Preparation of Trisubstituted Oxazoles
作者:Henrik v. Wachenfeldt、Philipp Röse、Filip Paulsen、Nagarajan Loganathan、Daniel Strand
DOI:10.1002/chem.201300019
日期:2013.6.10
end, an efficient gold‐catalyzed three‐component domino reaction to form oxazoles directly from imines, alkynes, and acid chlorides is presented. The reaction proceeds in a single synthetic step by using a gold(III)–N,N′‐ethylenebis(salicylimine) (salen) catalyst to give trisubstituted oxazoles in up to 96 % yield. The substrate scope, a mechanistic study exploring the role of the gold catalyst, and the
Electronically Mediated Selectivity in Ring Opening of 1-Azirines. The 3-X Mode: Convenient Route to 3-Oxazolines
作者:Marcus C. M. Sá、Albert Kascheres
DOI:10.1021/jo9518866
日期:1996.1.1
base-promoted reaction of methyl 2-phenyl-1-azirine-3-acetate (1) with aldehydes and acetone provides a new and simple route to the 3-oxazolines 5, which are formed in good yields by the electrophilic trapping of an imino anion produced by C-N bond cleavage in the 1-azirine enolate intermediate 6. Chloranil oxidation of 5 containing an aromatic substituent at C-2 affords oxazoles 7, while reaction of 5 containing