Thiazolium-Catalyzed Additions of Acylsilanes: A General Strategy for Acyl Anion Addition Reactions
作者:Anita E. Mattson、Ashwin R. Bharadwaj、Andrea M. Zuhl、Karl A. Scheidt
DOI:10.1021/jo060699c
日期:2006.7.1
utilizing N-heterocyclic carbenes (NHCs) derived from thiazolium salts has been developed for the generation of carbonyl anions from acylsilanes. Synthetically useful 1,4-diketones and N-phosphinoyl-α-aminoketones have been prepared in good to excellent yields via NHC-catalyzed additions of acylsilanes to the corresponding α,β-unsaturated systems and N-phosphinoylimines. These organocatalytic reactions
The Thiazolium-Catalyzed Sila-Stetter Reaction: Conjugate Addition of Acylsilanes to Unsaturated Esters and Ketones
作者:Anita E. Mattson、Ashwin R. Bharadwaj、Karl A. Scheidt
DOI:10.1021/ja0318380
日期:2004.3.3
A new acyl anion additionreaction between acylsilanes and alpha,beta-unsaturated conjugate acceptors promoted by a nucleophilic organic catalyst has been disclosed. The 1,4-dicarbonyl products produced in this reaction are highly useful synthons. Neutral carbenes (or zwitterions) generated in situ from commercial thiazolium salts are used as effective catalysts for the reaction which is in contrast
oxidative acylation of α,α‐diarylallylic alcohols with simple aromatic aldehydes for the synthesis of 1,2,4‐triphenylbutane‐1,4‐diones is presented. In the presence of TBPB (tert‐butyl peroxybenzoate), desired products were obtained in good to excellent yields for 28 examples. This protocol features high regioselectivity, wide functional group tolerance and atomeconomy.
Samarium-Promoted Michael Addition between Aroyl Chlorides and Chalcones
作者:Jun Wan、Yongjun Liu、Yuanying Li、Yan Qi
DOI:10.1055/s-0030-1258287
日期:2010.12
A novel Michael addition type reaction between aroyl chlorides and chalcones was realized in the presence of samarium metal when N,N-dimethylformamide was used as a solvent. A variety of 1,4-diketones were thereby synthesized in moderate to good yields. The possible mechanism is also discussed.
A convenient approach for the synthesis of substituted pyrroles by using phosphoric acid as a catalyst and their photophysical properties
作者:Yusuf Ajibola Ibrahim、Jiahui Li、Liankun Ai、Baolin Li
DOI:10.1016/j.molstruc.2021.132123
日期:2022.3
pyrrole compounds aside from six knowns, including the synthetically challenging tetra- and penta-substituted pyrroles from the corresponding 1,4-dicarbonyl through Paal-Knorr synthesis in the presence of 5% phosphoric acid as the catalyst. Our method is noteworthy for cheap catalyst, uncomplicated experimental setup under air atmosphere, scalability, and excellent yields. The fluorescence of some