A reaction mode of imines derived from naphthalene-1-carbaldehyde and acyclic alpha,beta-unsaturated aldehydes with organolitium reagents was dependent on the characteristic nature of a substituent on the imine nitrogen atom. An imine having an electron-withdrawing aryl group on the nitrogen atom behaves as a 1,2-directing imine toward organolithium reagents. In contrast, an imine bearing an alkyl
Enantioselective addition of various aryllithiumreagents to aromatic imines was catalyzed (20 mol-%) by readily accessible 1,2-diamines to afford a wide range of protected diarylmethylamines in up to 94 % enantiomeric excess. Furthermore, the absolute configuration of these arylation products was determined by using X-ray crystallography.
各种芳基锂试剂与芳族亚胺的对映选择性加成反应 (20 mol-%) 由易于获得的 1,2-二胺催化,得到多种保护的二芳基甲基胺,对映体过量高达 94%。此外,这些芳基化产物的绝对构型是通过使用 X 射线晶体学确定的。
Enantioselective addition of aryllithium reagents to aromatic imines mediated by 1,2-diamine ligands
A variety of optically enriched amines have been obtained by addition of aryllithiumreagents to aromatic imines using N,N′-tetramethylcyclohexane-1,2-diamine as chiral ligands. Enantiomeric excesses up to 90% could be obtained.