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.
Concise synthesis of valuable chiral N -Boc- β -benzyl- β -amino acid via construction of chiral N -Boc-3-benzyl-5-oxoisoxazolidine through cross-metathesis/conjugate addition/oxidation
作者:Hong-Tao Jiang、Hao-Ling Gao、Cheng-Sheng Ge
DOI:10.1016/j.cclet.2016.10.005
日期:2017.2
Abstract Valuable chiral N-Boc-β-benzyl-β-amino acid was concisely synthesized via construction of chiral N-Boc-3-benzyl-5-oxoisoxazolidine through cross-metathesis/conjugateaddition/oxidation. All of the starting materials for the synthesis of chiral N-Boc-β-benzyl-β-amino acid are cheap, and two-step short procedure make it easy for the rapid construction of various chiral β-arylmethyl-β-amino acids
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.
Catalytic Enantioselective [5+2] Cycloaddition between Oxidopyrylium Ylides and Enals under Dienamine Activation
作者:Ane Orue、Uxue Uria、Efraim Reyes、Luisa Carrillo、Jose L. Vicario
DOI:10.1002/anie.201410723
日期:2015.3.2
Benzopyrylium ylides generated in situ from 1‐acetoxyisochroman‐4‐ones reacted with α,β‐unsaturated aldehydes in the presence of a bifunctional secondary‐amine/squaramide catalyst to furnish [5+2] cycloaddition products in good yield with high diastereo‐ and enantioselectivity. The reaction proceeds by dienamine activation and involves β,γ‐functionalization of the enal. The dienamine intermediates