Bicyclic Pyrazolidinone Derivatives from Diastereoselective Catalytic [3 + 3]-Cycloaddition Reactions of Enoldiazoacetates with Azomethine Imines
摘要:
A highly regio- and diastereoselective synthesis of bicyclic pyrazolidinone derivatives by rhodium(II) acetate catalyzed [3 + 3]-annulation with enoldiazoacetates and azomethine imines has been achieved in high yield. A vinylogous reaction of the metal enol carbene with the azomethine imine Initiates [3 + 3]-cycloaddition, whereas reaction at the carbene center effects N-N-cleavage of the azomethine imine.
Catalytic [3 + 3]-Cycloaddition for Regioselective Preparation of Tricyclic Oxadiazines
作者:T. Prabhakar Reddy、A. Vamshi Krishna、Dhevalapally B. Ramachary
DOI:10.1021/acs.orglett.8b02719
日期:2018.11.16
Agrochemically useful and structurally important, functionally rich tricyclic-oxadiazines were synthesized in very good yields with excellent diastereoselectivities through a catalytic [3 + 3]-cycloaddition from the readily available p-quinols, azomethine imines, and a catalytic amount of Brønsted base (KOtBu).
Highly Selective Catalyst-Dependent Competitive 1,2-C→C, -O→C, and -N→C Migrations from β-Methylene-β-silyloxy-β-amido-α-diazoacetates
作者:Xichen Xu、Yu Qian、Peter Y. Zavalij、Michael P. Doyle
DOI:10.1021/ja311392m
日期:2013.1.30
Transition-metal catalysts direct 1,2-C→C, -O→C, and -N→C migrations from β-methylene-β-silyloxy-β-amido-α-diazoacetates with high selectivity. The key to achieving this unique display of differential selectivities relies on steric and stereoelectroniccontrol by their catalytically generated metal carbenes.