A Formal [3 + 3] Cycloaddition Reaction. 5. An Enantioselective Intramolecular Formal Aza-[3 + 3] Cycloaddition Reaction Promoted by Chiral Amine Salts
作者:Aleksey I. Gerasyuto、Richard P. Hsung、Nadiya Sydorenko、Brian Slafer
DOI:10.1021/jo050171s
日期:2005.5.1
A detailed account on chiral secondary amine salt promoted enantioselective intramolecular formal aza-[3 + 3] cycloadditions is described here for the first time. The dependence of enantioselectivity on the structural feature of these chiral amines is thoroughly investigated. This study also reveals a very interesting reversal of the stereochemistry in the respective cycloadducts obtained using C-1- and C-2-symmetric amine salts. In addition, the influence of solvents, counteranions, and temperatures on the enantioselectivity is described, and a unified mechanistic model based on experimental results as well as semiempirical calculations is proposed.
Meisenheimer rearrangements of N-allyl 2-azabornane derivatives
作者:Jonathan E. H. Buston、Iain Coldham、Keith R. Mulholland
DOI:10.1039/a903050f
日期:——
A study of the asymmetric [2,3]-Meisenheimer rearrangement of tertiary amine-N-oxides was carried out, in order to provide a method for the preparation of chiral allylic alcohols. The use of 2-azabornane as a chiralauxiliary gives rise to chiral tertiary amine-N-oxides, which undergo the [2,3]-Meisenheimer rearrangement with high levels of stereoselectivity. ReductiveN,O-bond cleavage, mediated by
Chirality Transfer from Nitrogen to Carbon in the [2,3]-Meisenheimer Rearrangement
作者:Jonathan Buston、Iain Coldham、Keith Mulholland
DOI:10.1055/s-1997-768
日期:1997.3
Oxidation of chiral, camphidin-based allylic tertiary amines gives rise to chiral tertiary amine-N-oxides, which undergo the [2,3]-Meisenheimer rearrangement with high levels of stereoselectivity. Reductive N,O-bond cleavage of the O-allyl-hydroxylamine gives access to the allylic alcohol unit.