Michael J. Ohlmeyer

Enantioselective hydroborations catalyzed by rhodium(+1) complexes

Abstract Enantioselective hydroborations of alkenes 1 - 4 with catecholborane were performed via catalysis with complexes containing the chiral ligands DIOP, BINAP, CHIRAPHOS , DIPAMP , BDPP , 2-MeODIOP , and 3-McODIOP . Alkenes 1 - 3 were also hydroborated with catecholborane derivatives 5 - 8 in the presence of Rh(+l)/ DIOP catalysts. Trends in the observed optical purities are discussed.

Diastereocontrol in rhodium-catalyzed hydroboration of chiral acyclic allylic alcohol derivatives

Abstract Diastereoselectivities in rhodium-catalyzed hydroborations of the chiral allylic alcohol derivatives (1) – (11) are governed predominantly by electronic and “shape” factors.

Substrate-controlled diastereoselectivity in catalyzed and uncatalyzed hydroborations of allylic amine derivatives

Abstract Hydroboration of the protected, homochiral allylic amines (6)–(10) with 9-BBN, and with catecholborane/rhodium catalyst, give different stereoselectivities; the catalyzed reactions provide access to syn -3-amino-2-methyl alcohols (11)–(15) .

On catalyzed and uncatalyzed hydroborations of chiral allylic alcohols and amines

Abstract A model for predicting the sense of diastereoselection in catalyzed hydroborations of allylic alcohol and allylic amine derivatives is discussed.