Catalytic Enantioselective Allenylation Reactions of Aldehydes with Tethered Bis(8-quinolinolato) (TBOx) Chromium Complex
作者:Guoyao Xia、Hisashi Yamamoto
DOI:10.1021/ja0679578
日期:2007.1.1
The utility of the new class of chiral ligand, tethered bis(8-quinolinol) (TBOxH), is further explored. Its chromiumcomplex, TBOxCr(III)Cl, effectively catalyzes the asymmetric allenylation reactions of various aldehydes at room temperature with high yields (up to 91%) and high enantioselectivities (up to 97% ee). The scope of the present method is shown to be wide, and this method represents an efficient
Efficient Synthesis of Optically Active 2,3-Allenols via the Simple CuBr-Mediated Reaction of Optically Active Propargylic Alcohols with Paraformaldehyde
作者:Shengming Ma、Hairong Hou、Shimin Zhao、Guangwei Wang
DOI:10.1055/s-2002-33656
日期:——
Enantiomerically enriched 2,3--allenols were prepared by the GuBr-mediated homologation of the relatively easily available opticallyactive teminal propargylic alcohols with paraformaldehyde in the presence of diisopropylamine.
Chiral Silver Phosphate-Catalyzed Cycloisomeric Kinetic Resolution of α-Allenic Alcohols
作者:Yan Wang、Kuan Zheng、Ran Hong
DOI:10.1021/ja300453u
日期:2012.3.7
A kinetic resolution of a-allenic alcohols is realized through chiral silver phosphate-catalyzed cycloisomerization with high stereoselectivity (selectivity factor up to 189) and tolerance of a variety of functional groups. A mechanistic model is proposed to interpret the origin of the high stereoselectivity and broad substrate scope.