Dimethylzinc-Mediated, Enantioselective Synthesis of Propargylic Amines
作者:Lorenzo Zani、Torsten Eichhorn、Carsten Bolm
DOI:10.1002/chem.200601347
日期:2007.3.16
A one-pot, enantioselective synthesis of N-aryl propargylic amines, using alkynylation reagents obtained from dimethylzinc and terminal acetylenes in combination with various aldehydes and o-methoxyaniline as starting materials, has been developed. Enantiopure beta-amino alcohols derivedfromnorephedrine were used as non-covalent chiral auxiliaries, both in stoichiometric or substoichiometric amount
Intermolecular [2 + 2] Cycloaddition/Isomerization of Allenyl Imides and Unactivated Imines for the Synthesis of 1-Azadienes Catalyzed by a Ni(ClO<sub>4</sub>)<sub>2</sub>·6H<sub>2</sub>O Lewis Acid
The intermolecular [2 + 2] cycloaddition/isomerization between allenyl imides and N-(2-methoxyphenyl) aldimine counterparts catalyzed by a Ni(ClO4)2·6H2O Lewisacid at room temperature was discovered, providing a facile access to 1-azadiene derivatives with high atom economy. The incorporation of an 2-oxazolidinone group into allene amides resulted in unusual reactivity for the imine-metathesis and
Asymmetric Mannich-type reactions with a chiral acetate: effect of Lewis acid on activation of aldimine
作者:Susumu Saito、Keiko Hatanaka、Hisashi Yamamoto
DOI:10.1016/s0040-4020(00)01042-5
日期:2001.1
addition. This scope was expanded to the asymmetric process using the chiral acetate, which has optically pure 2,6-bis(2-isopropylphenyl)-3,5-dimethylphenol as a chiralauxiliary with axial chirality. A Lewis acid additive is likely to have a complementary role in the pronounced activation of imine functionalities in the Mannich-type addition of the bulky chiral acetate.
Pyrrole-based silyl dienolates undergo asymmetric vinylogous Mukaiyama Mannich reactions with a series of N-aryl aldimines in the presence of the Hoveyda-Snapper amino acid-derived silver(I) catalysts. The Manrdch products alpha,beta-unsaturated delta-ammo-gamma-butyrolactams-are typically obtained in high yields, excellent gamma-site selectivities and anti-diastereoselectivities, and up to 80% enantioselectivity.
A stereoselective, multiple-component approach to α–β-substituted-β-amino carbonyl derivatives
作者:Avrum L. Joffe、Timothy M. Thomas、James C. Adrian
DOI:10.1016/j.tetlet.2004.04.170
日期:2004.6
A new stereoselective multiple-component condensation is presented. This three-component condensation combines an aldehyde. aniline. and chlorotitanium enolates, to afford alpha-beta-substituted-beta-amino carbonyl compounds as its core structure. (C) 2064 Elsevier Ltd. All right reserved.