Enantiomerically Pure Cyclic trans-1,2-Diols, Diamines, and Amino Alcohols by Intramolecular Pinacol Coupling of Planar Chiral Mono-Cr(CO)3 Complexes of Biaryls
作者:Nobukazu Taniguchi、Takeshi Hata、Motokazu Uemura
DOI:10.1002/(sici)1521-3773(19990503)38:9<1232::aid-anie1232>3.0.co;2-e
日期:1999.5.3
Without any formation of stereoisomers, the intramolecular pinacol cyclization of 1-planar chiral mono-Cr(CO)3 complexes of 1,1'-biphenyls with carbonyl functionalities at the 2- and 2'-positions-with samarium diiodide gives cyclic trans-1,2-diols 2. Upon exposure to sunlight, the chromium-complexed diols 2 produce optically pure chromium-free trans-diols 3. Similarly, the corresponding enantiomerically pure trans-1,2-diamines and amino alcohols are obtained from the planar chiral chromium complexes of biphenyls with diimino or keto-imino functionalities. R1 =H, OMe; R2 =H, Me; R3 =H, Me.