Solid-State Structural Investigation of an Organolithium (−)-Sparteine Complex:η3-N-Boc-N-(p-methoxyphenyl)-3-phenylallyllithium⋅(−)-Sparteine
摘要:
A η3 monomeric alkyllithium⋅(-)-sparteine complex has been isolated and characterized in the solid state (see picture). Determination of the absolute configuration of this key intermediate in asymmetric metalation/substitution sequences of N-tert-butoxycarbonyl-N-(p-methoxyphenyl)cinnamylamine allows definitive assignment of the stereochemical course of its electrophile-dependent substitution reactions.
Kinetic Resolution of Racemic Lactones by Conjugate Additions of Allylic Organolithium Species: Direct Formation of Three Contiguous Centers with High Diastereo- and Enantioselectivities
作者:Sung H. Lim、Peter Beak
DOI:10.1021/ol0263898
日期:2002.8.1
[reaction: see text] Kinetic resolution of racemic alpha,beta-unsaturated lactones by the organolithium species produced from asymmetric lithiation of N-Boc-N-(p-methoxyphenyl)cinnamylamine provides conjugateaddition products with three contiguous stereogenic centers in yields of 62-77% with diastereomeric ratios from 75:25 to >99:1 and enantiomeric ratios for the major diastereomers from 94:6 to 98:2
Ligand Control and Asymmetric Michael Reactions of Enantioenriched Configurationally Stable <i>N-</i>Boc Anilino Benzylic and Allylic Organolithium Species
作者:Yong Sun Park、Gerald A. Weisenburger、Peter Beak