Lewis acid-catalyzed asymmetric radical additions of trialkylboranes to (1 R,2 S,5 R)-2-(1-methyl-1-phenylethyl)-5-methylcyclohexyl-2 H-azirine-3-carboxylate

Abstract

The asymmetric addition of alkyl radicals to (1 R,2 S,5 R)-2-(1-methyl-1-phenylethyl)-5-methylcyclohexyl-2 H-azirine-3-carboxylate ( 1 ) yielding the corresponding 2-alkylaziridine-2-carboxylates has been investigated. High diastereoselectivities and good yields were obtained in the addition of primary alkyl radicals to azirine 1 , while secondary radicals gave a lower dr. The influence of Lewis acids was also investigated; 10 mol% of CuCl were found to increase the dr.