Nucleophilic Ring Opening of Cyclic 1,2-Sulfites with Nitrogen Nucleophiles. A Route to Enantiopure Benzylic Amino Alcohols.
作者:Kirsten Nymann、Saravanapavan Mylvaganam、John S. Svendsen、Inamur Rahaman Laskar、Nirmalendu Ray Chaudhuri、Kirsi Ranta、Teófilo Rojo
DOI:10.3891/acta.chem.scand.52-1060
日期:——
The reaction between cyclic 1,2-sulfites and two imide and two sulfonamide nucleophiles has been Investigated in order to develop a procedure for the enantioselective preparation of N-protected vicinal amino alcohols. The results show that both imide and sulfonamide anions react with cyclic sulfites, yielding the desired products. In some cases the regioselectivities are low, and for the sulfonamides products originating from nucleophilic addition to the sulfite sulfur are observed.
Two Efficient Enantioselective Syntheses of 2-Amino-1-phenylethanol
作者:Setrak K. Tanielyan、Norman Marin、Gabriela Alvez、Robert L. Augustine
DOI:10.1021/op060122x
日期:2006.9.1
Two enantioselective methods for the synthesis of 2-amino-1-phenylethanol have been developed. The first utilizes an enantioselective oxazaborolidine-catalyzed borane reduction of 2-chloroacetophenone (phenacyl chloride) to give the chiral chloro alcohol in good yield with an ee in the 93−97% range. Reaction with dilute ammonium hydroxide produced the amino alcohol in good yield with a high ee. The