Synthesis and Resolution of a Novel Chiral Diamine Ligand and Application to Asymmetric Lithiation−Substitution
作者:Xiaolin Li、Laurie B. Schenkel、Marisa C. Kozlowski
DOI:10.1021/ol9903133
日期:2000.4.1
[GRAPHICS]A short, efficient synthesis of chiral 1,5-diaza-cis-decalins (7) is presented. In the lithiation of N-Boc pyrrolidine, the ligands with the smallest most electron rich R groups (Me > Et > (CH2Bu)-Bu-t > CH2CF3 approximate to Bn) were most effective. In the asymmetric deprotonation/substitution of benzylic substrates, (R,R)-7 (R = Me, R' = H) conferred modest selectivity. The ready availability of both enantiomers of the 1,5-diaza-cis-decalins and the ability to tune steric and electronic properties renders these compounds an attractive new class of diamine ligands.
Enantioselective Oxidative Biaryl Coupling Reactions Catalyzed by 1,5-Diazadecalin Metal Complexes
作者:Xiaolin Li、Jaemoon Yang、Marisa C. Kozlowski
DOI:10.1021/ol015595x
日期:2001.4.1
Chiral 1,5-diaza-cis-decalins have been examined as ligands in the enantioselective oxidative biaryl coupling of substituted 5-naphthol derivatives. Under the optimal conditions employing a 1,5-diaza cis-decalin copper(l) iodide complex with oxygen as the oxidant, rapid and highly selective couplings could be achieved (90-93% ee, 85% yield).