N-allylynamides with various functional groups and different substitution patterns can be converted into 3-aza-bicyclo[3.1.0]hexan-2-one derivatives in moderate to high yield using IMesAuCl/AgBF4 as the catalyst and pyridine N-oxide as the oxidant. A noncarbene mediated approach is proposed as the mechanism.

α-Imino rhodium carbenoids generated from 1-sulfonyl 1,2,3-triazole were applied to the 3 + 2 cycloaddition with ketene silyl acetal, offering a novel and straightforward synthesis of biologically interesting compound 3-pyrrolin-2-one with broad substrate scope.

α-Imino rhodium carbene, readily generated from N-sulfonyl-1,2,3-triazole, underwent cycloaddition and subsequent rearrangement with a nitrosobenzene derivative to afford N-acylamidine. The unprecedented C-C bond cleavage of α-imino carbene was facilitated by the weakness of the N-O bond.

The efficient synthesis of highly functionalized furan derivatives from 1-sulfonyl-1,2,3-triazoles with a pendent carbonyl group is reported. The process involves an intramolecular trapping of α-imino carbene and subsequent aromatization.

Sulfonyl-1,2,3-triazoles. -The utility of the products is demonstrated by their use as tosylimino transfer agent for the formation of formimidamides. -(RAN, R.-Q.; XIU, S.-D.; LI*, C.-Y.; Org. Lett. 16 (2014) 24, 6394-6396, http://dx.