N-Substitution dependent stereoselectivity switch in palladium catalyzed hydroalkynylation of ynamides: a regio and stereoselective synthesis of ynenamides
N-Substitution dependent stereoselectivity switch in palladium catalyzed hydroalkynylation of ynamides: a regio and stereoselective synthesis of ynenamides
作者:Vikas Dwivedi、Madala Hari Babu、Ruchir Kant、Maddi Sridhar Reddy
DOI:10.1039/c5cc06251a
日期:——
A palladium catalysed regioselective hydroalkynylation of ynamides for ynenamides is achieved with an N-substitution dependent stereoselectivity switch.
通过钯催化的选择性加氢炔化反应,可以将炔酰胺转化为烯酰胺,其立体选择性取决于N-取代基的选择。
Enantioselective Ficini Reaction: Ruthenium/PNNP-Catalyzed [2+2] Cycloaddition of Ynamides with Cyclic Enones
作者:Christoph Schotes、Antonio Mezzetti
DOI:10.1002/anie.201007753
日期:2011.3.21
Chiral cyclobuteneamides made easy: Double chloride abstraction from the ruthenium/PNNP complex 1 in the presence of unsaturated β‐keto esters 2 gives the dicationic adducts [Ru(2)(PNNP)]2+ (3) that catalyze the [2+2] cycloaddition of a variety of ynamides 4 to produce cyclobuteneamides 5 with high yield and enantioselectivity (see scheme).
Tf<sub>2</sub>NH-Catalyzed Formal [3 + 2] Cycloaddition of Ynamides with Dioxazoles: A Metal-Free Approach to Polysubstituted 4-Aminooxazoles
作者:Yingying Zhao、Yancheng Hu、Chunxiang Wang、Xincheng Li、Boshun Wan
DOI:10.1021/acs.joc.7b00076
日期:2017.4.7
An unprecedented Tf2NH-catalyzed formal [3 + 2] cycloaddition of ynamides with dioxazoles was developed to construct various polysubstituted 4-aminooxazoles. This approach features a metal-free catalytic bimolecular assembly of oxazole motifs, a low-cost catalyst, exceptionally mild reaction conditions, a very short reaction time, a broad substrate scope, and high efficiency. This metal-free protocol
A gold mine of results: A series of ynamides have been dimerized in the presence of a gold(I) complex. This unprecedented transformation involves the formation of a key keteniminium intermediate that reacts to form a variety of cyclic and acyclic products. The substitution pattern of the ynamide determines which product is formed (see scheme; EWG=electron‐withdrawing group, Ts=p‐toluenesulfonyl).
Cu(I)- and Cu(II)-Catalyzed Cyclo- and Michael Addition Reactions of Unsaturated β-Ketoesters
作者:Christoph Schotes、Antonio Mezzetti
DOI:10.1021/jo200776c
日期:2011.7.15
ethynyl(phenyl)sulfane (4) ([2 + 2] cycloaddition), and 1,2,5-trimethyl-1H-pyrrole (5) (Michael addition) in the presence of copper(I) (6) or copper(II) triflate (7) (1–2 mol %) in dichloromethane. This convenient protocol converts 1a and 1b to the corresponding cycloaddition (8–10) or Michael addition (11) products in good yields after reaction times of 0.5–3 h without requiring purified solvents