Synthesis of a 1,3-spiro-amino-alcohol-derived chiral auxiliary and its application to Diels–Alder reactions
摘要:
A short synthesis and resolution of (1R,5R,6R)-6-aminospiro[4.4]nonan-2-ol, 11, is reported. The pivalamide derivative (+)-5 gives excellent diastereo- and regiocontrol as well as endo selectivity as a chiral auxiliary in the BCl3-catalyzed Diels-Alder reaction with a variety of symmetrical and unsymmetrical dienes. The adducts are readily cleaved by saponification, allowing recovery and reuse of (+)-5. (C) 2003 Elsevier Science Ltd. All rights reserved.
Synthesis of a 1,3-spiro-amino-alcohol-derived chiral auxiliary and its application to Diels–Alder reactions
摘要:
A short synthesis and resolution of (1R,5R,6R)-6-aminospiro[4.4]nonan-2-ol, 11, is reported. The pivalamide derivative (+)-5 gives excellent diastereo- and regiocontrol as well as endo selectivity as a chiral auxiliary in the BCl3-catalyzed Diels-Alder reaction with a variety of symmetrical and unsymmetrical dienes. The adducts are readily cleaved by saponification, allowing recovery and reuse of (+)-5. (C) 2003 Elsevier Science Ltd. All rights reserved.
Development of P-stereogenic 2-phenyl-1,3,2-oxazaphosphorine ligands and their unexpected sensitivity to oxidation
作者:Wendy L. Benoit、Masood Parvez、Brian A. Keay
DOI:10.1016/j.tetasy.2008.12.027
日期:2009.1
P-Stereogenic oxazaphosphorine compounds of the form 4 have not previously been reported as asymmetricligands for metal-catalyzed reactions. In an effort to explore the behavior of such oxazaphosphorine ligands, monomeric oxazaphosphorine borane 9 and dimeric oxazaphosphorine boranes 25 and 26 were synthesized as catalyst precursors. The absolute configuration of the phosphorus center contained in