to variously substituted tetrahydroisoquinolines, allows asymmetric C-C bond forming reactions to occur α- to the amino group. In this manner, a wide variety of (S)-1-alkyl-1,2,3,4-tetrahydroisoquinolines were constructed in > 90% enantiomeric excess. Choosing the proper substituents and skeletal features, an efficient entry into the benzylisoquinoline, tetrahydroprotoberberine, aporphine, and isopavine
Stereoselective α-Methylation of N-Methyl Benzylamine via a Combination of Chromium Tricarbonyl and Chiral Formamidine Methodologies
作者:Joan Albert、Stephen G Davies
DOI:10.1016/s0040-4039(01)93512-9
日期:——
Whereas carbanions of formamidines derived from N-methyl benzylamine and L-valinol or L-leucinol undergo electrophilic benzylic methylation with poor stereoselectivities (d.e. 17–26%), enhanced stereoselectivities (d.e. 74–84%) are observed for the corresponding chromium tricarbonyl complexes.