Organoselenium-Catalyzed, Hydroxy-Controlled Regio- and Stereoselective Amination of Terminal Alkenes: Efficient Synthesis of 3-Amino Allylic Alcohols
摘要:
An efficient route to prepare 3-amino allylic alcohols in excellent regio- and stereoselectivity in the presence of bases by orangoselenium catalysis has been developed. In the absence of bases alpha,beta-unsaturated aldehydes were formed in up to 97% yield. Control experiments reveal that the hydroxy group is crucial for the direct amination.
Enantio- and Diastereoselective Synthesis of Substituted Tetrahydro-1<i>H</i>-isochromanes through a Dynamic Kinetic Resolution Proceeding under Dienamine Catalysis
作者:Ane Orue、Efraím Reyes、Jose L. Vicario、Luisa Carrillo、Uxue Uria
DOI:10.1021/ol301602h
日期:2012.7.20
nes react with enolizable α,β-unsaturatedaldehydes in the presence of a chiral secondary amine catalyst furnishing a wide range of differently substituted tetrahydro-1H-isochromanes with excellent results. The reaction relies on the activation of the enal by the catalyst through the formation of a dienamine intermediate, which undergoes a Diels–Alder/elimination cascade reaction. Moreover, the overall
Dienamine-Mediated Inverse-Electron-Demand Hetero-Diels-Alder Reaction by Using an Enantioselective H-Bond-Directing Strategy
作者:Łukasz Albrecht、Gustav Dickmeiss、Christian F. Weise、Carles Rodríguez-Escrich、Karl Anker Jørgensen
DOI:10.1002/anie.201207122
日期:2012.12.21
Giving directions: optically active dihydropyrans bearing three contiguous stereogenic centers can be efficiently prepared by the title reaction. High stereo- and regiocontrol can be achieved by employing a bifunctional H-bond-directing aminocatalyst.