Remarkable anion effects uncovered in the development of a Au(iii)-catalyzed tandem nucleophilic substitution–1,5-enyne cycloisomerization process
作者:Jonathan P. Reeds、Adrian C. Whitwood、Mark P. Healy、Ian J. S. Fairlamb
DOI:10.1039/b925919h
日期:——
(I(t)Pe)AuBr(2)(N-imidate) complexes, prepared in high yield by oxidative bromination, are active catalysts for 1,5-enyne cycloisomerization. An efficient tandem nucleophilic substitution-1,5-enyne cycloisomerization is promoted by these novel Au(III) precatalysts. Catalyst efficacy is affected by the imidate ligand and the silversalt used (e.g. Ag[Al(OC(CF(3))(3))(4)]).
alcohols with aryl nucleophiles were studied. Highly selective and tunable synthetic methods were developed for one-pot formation of either triaryl-allenes, diaryl-indenes or tetraaryl-allyl target products by appropriate reaction conditions (time, temperature, catalyst, substrate, nucleophile, solvent). Corresponding 2-halo-indenes, appropriate for further Pd-catalyzed reactions, were also obtained
Gold(III) or Gold(I)/Lewis-Acid-Catalyzed Substitution/Cyclization/1,2-Migration Reactions of Propargyl Alcohols with 3-Amino-benzo[<i>d</i>]isoxazoles: Synthesis of Pyrimidine Derivatives
作者:Ali Wang、Mingduo Lu、Xin Xie、Yuanhong Liu
DOI:10.1021/acs.orglett.2c01011
日期:2022.4.22
A straightforward synthesis of pyrimidines via Au(III) or Au(I)/Lewis-acid-catalyzed cascade reactions of propargylalcohols with 3-amino-benzo[d]isoxazoles is described. The propargyl amine intermediates are readily generated in situ via oxophilic activation of gold(III) or a Lewis acid, which undergo cyclization/1,2-group migration/aromatization to deliver the desired products. Highly selective 1
Selective 5‐Exo‐Dig versus 6‐Endo‐Dig Cyclization of Benzoimidazole Thiols with Propargyl Alcohols
作者:Tales A. C. Goulart、Ana M. S. Recchi、Davi F. Back、Gilson Zeni
DOI:10.1002/adsc.202200254
日期:2022.6.21
here the Lewis acid-promoted cyclization reaction of benzomidazole thiols with propargyl alcohols for the selective synthesis of benzoimidazolo thiazines and benzothiazolo imidazoles. The reaction is regioselective and the solvent controls the formation of products. The systematic study to determine the best reaction conditions revealed that the six-membered benzoimidazolo thiazines were obtained by
One-Pot Synthetic Approach to 3-Carboxyl- and 3-Ketopyridines in Aqueous Media
作者:Aleksander R. Bena、Evangelos G. Bakalbassis、Michail M. Sigalas、Ioannis N. Lykakis
DOI:10.1021/acs.joc.3c00067
日期:2023.7.7
We describe a one-pot strategy to access 3-carboxyl- and 3-ketopyridines from readily available alkynes and propargylamine via a hydroamination process. This one-pot protocol uses alkynes as starting materials, has a broad substrate scope, and operates in aqueousmedia and open-air conditions. A series of aryl- and alkyl-substituted pyridines were synthesized. This green methodology can be scaled to