Enantioselective Synthesis of Chiral Homoallyl Alcohols and Homoallylamines by Nucleophilic Addition of an Allylboron Reagent Modified by a Polymer-Supported Chiral Ligand
作者:Shinichi Itsuno、Katsuhiro Watanabe、Ashraf A. El-Shehawy
polymer-supported chiral N-sulfonylamino alcohols 5–8 have been prepared by suspension polymerization of enantiopure N-sulfonylamino alcohol monomers 1–4 with styrene and divinylbenzene. Polymer-supported chiralallylboronreagents were prepared from the polymeric chiral ligands. Enantioselectiveadditions of the polymer-supported allylboronreagents to aldehydes and N-(trimethylsilyl)imines have been successfully
Enantioselective allylation of N-(trimethylsilyl)benzaldehyde imine using polymer-supported chiral allylboron reagents
作者:Ashraf A El-Shehawy、Magdy Y Abdelaal、Katsuhiro Watanabe、Koichi Ito、Shinichi Itsuno
DOI:10.1016/s0957-4166(97)00184-5
日期:1997.6
trimethallylborane, and tri(3,3-dimethylallyl)borane, respectively, to give polymeric allylating agents. N-(Trimethylsilyl)benzaldehyde imine was allowed to react with the polymeric chiral reagents to afford the corresponding primary homoallylamines in high yield and good enantioselectivities.
Optical Resolution of (RS)-Pantolactone through Amide Formation
作者:Christian Fizet
DOI:10.1002/hlca.19860690220
日期:1986.3.19
The opticalresolution of (RS)-pantolactone (1) is carried out throughformation of diastereoisomeric amides. These are separated by a single hot washing with CH2C12 or CHC13. The used asymmetric amine, (1R)-3-endo-aminoborneol (4), is readily accessible and can be recovered almost quantitatively after resolution.
Asymmetric Reduction of Ketones Using<i>In Situ</i>Generated Oxazaborolidines From (1<i>R</i>-Camphor as Catalysts
作者:V. Santhi、J. Madhusudana Rao
DOI:10.1080/00397910008087056
日期:2000.12
Abstract Benzyl and 1-naphthyl derivatives of 1,2-amino alcohols derived from (1R)-(+)-camphor were made by a simple and efficient procedure and these were used for the generation of oxazaborolidines with borane. The asymmetricreductions of prochiralketones were carried out using these in situ generated oxazaborolidines as catalysts.
Diastereocontrolled synthesis of optically pure functionalized heterohelicenes
作者:Kazuhiko Tanaka、Hideji Osuga、Hitomi Suzuki
DOI:10.1016/s0957-4166(00)80425-5
日期:1993.8
preparation of functionalized opticallypureheterohelicenes. The diastereoselectivities in the synthesis of the helicenes via photocyclization were controlled by the use of these chiral auxiliaries and the resulting diastereomers were readily separated by column chromatography. Removal of the chiral auxiliaries gave opticallypure (+)-(P)- and (−)-(M)-[7]heterohelicenes, whose rotational values were