ChemInform Abstract: Construction of β‐Lactams by Highly Selective Intramolecular C‐H Insertion from Rhodium(II) Carboxylate Catalyzed Reactions of Diazoacetamides.

Abstract

Treatment of the diazoacetoacetamides (I), (III), and (VI) with catalytic amounts of dirhodium tetraacetate leads selectively to the formation of the β‐lactams (II), (IV), and (V) or (VII).

Rhodium(II)-catalyzed cyclization of 2-alkynyl 2-diazo-3-oxobutanoates as a method for synthesizing substituted furans

“…63 There have also been several recent examples of C-H insertions leading to fourand six-membered rings as well as facile C-H bond insertion in both a constrained rigid64 and even acyclic systems. 65 These results indicate that site selectivity depends on the nature of the -diazo carbonyl compound and also suggests that it is governed by steric and conformational factors as well as electronic factors. During the course of our studies dealing with the 1,5-electrocyclization reaction of alkynyl 2-diazo-3-oxobutanoates, we found that the C-H insertion reaction can compete with furan formation when an alkyl group was attached to the keto functionality.…”