Formation of Tertiary Alcohols from the Rhodium-Catalyzed Reactions of Donor/Acceptor Carbenes with Esters.

Rhodium(II)-catalyzed reactions between isopropyl acetate and trichloroethyl aryldiazoacetates result in the formation of oxirane intermediates that ring open under the reaction conditions to form tertiary alcohols. When the reaction is catalyzed by the dirhodium tetrakis(triarylcyclopropanecarboxylate) complex, Rh2( S-2-Cl,4-BrTPCP)4, the tertiary alcohols are formed with good asymmetric induction (80-88% ee).