Controlling the regiochemistry of nucleophilic attack on unsymmetrical allyl complexes.

J.W. FALLER; C. LAMBERT ; M.R. MAZZIERI

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 1990 vol. 383 p. 161 - 161

he NO and CO ligands in a [CpMo(NO)(CO)( $-allyl)]+ complex exert differentialelectronic effects on the ally1 moiety and control the regiochemistry ofnucleophilic attack. These directing influences are sufficiently strong that theyovercome the normal directing influences of substituents of the ally1 moiety. Anessential task, therefore, is arranging for the appropriate terminus of the ally1 tohave the relationship to the nitrosyl group that will result in attack at the desiredlocation. Replacement of a single CO ligand in a neutral monosubstituted ally1complex of CpMo(CO), with NO+ yields a product for which addition occurs at theunsubstituted end of the allyl. Hence, an E-olefin with no newly created chiralcenters is formed upon nucleophilic attack. A new synthetic strategy has beendeveloped which allows us to build a chiral center in the allylic position of aterminal olefin. Sequential addition of two nucleophiles to a