Diboron-Assisted Copper-Catalyzed Z-Selective Semihydrogenation of Alkynes Using Ethanol as a Hydrogen Donor
摘要:
We herein describe a B(2)Pin(2)-assisted copper-catalyzed semihydrogenation of alkynes. A variety of alkenes were obtained in good to excellent yields with Z-selectivity under mild reaction conditions. Mechanistic studies indicated that a transfer hydrogenation process was involved and ethanol acted as both a solvent and a hydrogen donor in this reaction. The present protocol enabled convenient synthesis of deuterium-substituted Z-alkenes such as Z-Combretastain A4-d(2) in a high deuteration ratio by using readily available ethanol-d(1) as the deuterium source.
as Raschig rings or placed within the PASSflow TM microreactor affords technical devices that are well suited for performing palladium-catalyzed carbon-carbon cross-couplingreactions in the flow-through mode. Reusability of the immobilized precatalyst as well as applications in the microwave field were investigated. Experiments with thiol- and pyridine-based scavengers were carried out, which revealed
Treatment of internal alkynes with sodium methoxide in the presence of Pd(OAc)2 and PPh3 in methanol for 48 h gave the reduction products, alkenes or alkanes in good chemical yields. This reaction proceeds through a palladium methanolate complex, followed by β-hydride elimination and reductive elimination.
Antiarrhythmic agents. 2-, 3-, and 4-Substituted benzylamines
作者:David C. Remy、William A. Van Saun、Edward L. Engelhardt、Mary L. Torchiana、Clement A. Stone
DOI:10.1021/jm00236a006
日期:1975.2
The synthesis of a series of 2-, 3-, and 4-substituted benzylamine derivatives is described. These compounds were studied for their effect on experimental cardiac arrhythmias. Many of the derivatives, but in particular 2-(p-methoxyphenylethynyl)benzylamine (3d), alpha,alpha-dimethyl-4y(phenylethynyl)benzylamine (7a), and alpha,alpha-dimethyl-4-phenethylbenzylamine (12g), showed good antiarrhythmic activity.
The Preparation of and the Spectral Characteristics of Some 2-Substituted cis- and trans-Stilbenes<sup>1</sup>
作者:DeLos F. DeTar、Louis A. Carpino
DOI:10.1021/ja01583a061
日期:1956.1
Palladium‐Catalyzed C−H Alkynylation of Unactivated Alkenes
作者:Benedikt S. Schreib、Marlene Fadel、Erick M. Carreira
DOI:10.1002/anie.202000935
日期:2020.5.11
Palladium-catalyzedregio- and diastereoselective C-H functionalization with bromoalkynes and electronically unbiased olefins is reported. The picolinamide directing group enables the formation of putative 5 and 6-exo-metallacycles as intermediates to afford monoalkynylated products in up to 91 % yield in a stereospecific fashion. The systematic study reveals that substrates with a wide range of substituents