AsPh3-catalyzed ylide cyclopropanation for the synthesis of trisubstituted vinylcyclopropane derivatives

Under mild conditions, the reaction of alkylidene, arylidene, and heteroarylidene malonates with tosylhydrazone salts in the presence of catalytic amount of Rh2(OAc)4 and triphenylarsine affords trans-2,3-disubstituted cyclopropane 1,1-dicarboxylic esters in high yields and high diastereoselectivities.