DIASTEREOSELECTIVE 1,2-ADDITIONS OF NUCLEOPHILES TO QUINOLINE COMPLEXES OF THE CHIRAL RHENIUM LEWIS-ACID [(ETA(5)-C5H5)RE(NO)(PPH(3))](+) Academic Article uri icon

abstract

  • The racemic or optically active quinoline complexes [(5-C5H5)Re(NO)(PPh3)NC9H7)+TfO (1) and RLi (R = (a) CH2Si(CH3)3, (b) CH3, (c) C6H5) rapidly react in THF at 80 C to give the 1,2 addition products (5-C5H5)Re(NO)(PPh3)(NCH(R)CH=CHC(CH)4C), which contain new carbon stereocenters. Under optimum conditions, diastereoselectivities are 92%. Subsequent reactions with HOTf give mixtures of amine complexes (3) and alkene complexes (4) of the formulas [(5-C5H5)Re(NO)(PPh3)(NHCH(R)CH=CHC(CH)4C]+TfO. The latter dominate at equilibrium. The crystal structure of 4c establishes the carbon configurations, which are consistent with RLi attack from a direction anti to the bulky PPh3 ligand in 1. Reaction of (S)-1 and (CH3)2CHMgCl at 80 C gives the 1,4 addition product (5-C5H5)Re(NO)(PPh3)(NCH=CHCH(CH(CH3)2)C(CH)4C) as a 66:34 mixture of diastereomers. Reaction with HOTf gives the imine complex [(5-C5H5)Re(NO)(PPh3)(N=CHCH2CH(CH(CH3)2C(CH)4C)]+TfO. Stereochemical features of the preceding compounds and transformations are analyzed in detail. 1994, American Chemical Society. All rights reserved.

published proceedings

  • ORGANOMETALLICS

author list (cited authors)

  • STARK, G. A., ARIF, A. M., & GLADYSZ, J. A.

citation count

  • 24

complete list of authors

  • STARK, GA||ARIF, AM||GLADYSZ, JA

publication date

  • November 1994