Diisobutylaluminum hydride (DIBAL-H) reduces nitriles to give N-diisobutylaluminum imines, which were asymmetrically allylated with chirallymodifiedallylboronreagents. The corresponding chiral primary homoallylamines were obtained with up to 87% ee.
Asymmetric addition of butyllithium to N-Metallo imines of benzaldehyde
作者:Shinichi Itsuno、Mamiko Sasaki、Shizue Kuroda、Koichi Ito
DOI:10.1016/0957-4166(95)00184-q
日期:1995.7
benzaldehyde such as N-aluminium imine, N-boryl imine and N-silyl imine were asymmetrically alkylated with butyllithium in the presence of chiral ligands including (−)-sparteine and proline-derived amino alcohols to give optically active 1-phenylpentyl-1-amine in up to 74 % enantiomeric excess. Polymer-supported chiral ligands were also used for the asymmetric addition.
Asymmetric γ-Methoxyallylation with the Robust 10-TMS-9-Borabicyclo[3.3.2]decanes
作者:Lorell Muñoz-Hernández、John A. Soderquist
DOI:10.1021/ol900865y
日期:2009.6.18
The asymmetric gamma-methoxyallylboration of aldehydes with the configurationally very stable 1 gives nonracemic threo-beta-methoxyhomoallylic alcohols 7 (65-93%) with excellent selectivity (96-99% de, 98-99% ee). The corresponding homoallylic amines 10 are obtained from N-H aldimines with similar efficiency (72-96%) and with excellent diastereoselectivity (98% de) but with lower enantioselectivity (56-86% ee). These new reagents provide ready access to a Taxol side chain derivative.
ANDREOLI, PATRIZIA;BILLI, LAURA;CAINELLI, GIANFRANCO;PANUNZIO, MAURO;MART+, J. ORG. CHEM., 55,(1990) N3, C. 4199-4200