Synthesis and calcium antagonistic activity of diethyl styrylbenzylphosphonates
摘要:
Twenty-three new phosphonic ester derivatives of stilbene exhibiting structural analogies with fostedil are described. Examination of calcium antagonism showed that this activity could not be increased by introducing electron-withdrawing, electron-releasing or lipophilic substituents. Only compounds containing fluorine at the 2 or 4 positions exhibited similar activity to the model.
Redesign of a Pyrylium Photoredox Catalyst and Its Application to the Generation of Carbonyl Ylides
作者:Edwin Alfonzo、Felix Steven Alfonso、Aaron B. Beeler
DOI:10.1021/acs.orglett.7b01222
日期:2017.6.2
We report the exploration into photoredox generation of carbonylylides from benzylic epoxides using newly designed 4-mesityl-2,6-diphenylpyrylium tetrafluoroborate (MDPT) and 4-mesityl-2,6-di-p-tolylpyrylium tetrafluoroborate (MD(p-tolyl)PT) catalysts. These catalysts are excited at visible wavelengths, are highly robust, and exhibit some of the highest oxidation potentials reported. Their utility
The first catalytic dehydrative condensation of the benzylic C-H bonds of toluene and p-xylene with aromatic aldehydes is reported herein. This protocol provides highly atom-economical access to stilbene and p-distyrylbenzene derivatives, whereby water is the sole byproduct. The reaction is based on the deprotonation-functionalization of benzylic C-H bonds through η6-complexation of the arenes, which
本文报道了甲苯和对二甲苯的苄基 CH 键与芳香醛的第一次催化脱水缩合。该协议提供了对二苯乙烯和对二苯乙烯基苯衍生物的高度原子经济访问,其中水是唯一的副产品。该反应基于通过芳烃的 η6-络合实现苄基 CH 键的去质子化功能化,这是首次使用催化量的过渡金属活化剂实现的。该方法成功的关键是使用磺酰胺阴离子作为催化剂组分,这似乎不仅有助于苄基 CH 键的去质子化,而且还有助于通过亲电子甲苯磺酸亚胺中间体形成 CC 键。
Transition‐Metal‐Free Olefinic C−H Azidoalkylthiolation
<i>via</i>
C(
<i>sp</i>
<sup>3</sup>
)−S Bond Cleavage of Vinylsulfonium Salts
A transition-metal-free olefinicC−Hazidoalkylthiolation protocol was developed through C(sp3)−Sbondcleavage of vinylsulfoniumsalts with sodium azide in air under aqueous conditions. An interrupted Pummerer/nucleophilc azidoalkylation cascade was developed for such a process. The practicability of the synthetic protocol was demonstrated by scale-up preparation of the azidoalkylthiolated tetrasubstituted
Various Heck couplings have been carried out using segmented flow conditions to accelerate the reactions. Aryl iodides and aryl bromides as well as anilines in diazonium-type Heck reactions have been used Successfully. (C) 2009 Elsevier Ltd. All rights reserved.
Open-air oxidative Mizoroki–Heck reaction of arylsulfonyl hydrazides with alkenes
作者:On Ying Yuen、Chau Ming So、Fuk Yee Kwong
DOI:10.1039/c6ra03188a
日期:——
A palladium(II)-catalyzed oxidative Mizoroki–Heckreaction of arylsulfonyl hydrazides with alkenes was developed employing atmospheric air as the sole oxidant in an open-vessel manner. By using palladium(II) acetate associating with inexpensive, air-stable and moisture stable pyridine ligand L9 as the catalyst system, the efficiency of the reaction could be significantly enhanced. A wide range of arylsulfonyl