描述了一种通过二酰亚胺还原策略合成α-取代的乙基膦酸酯的简单直接的方法。以K 3 PO 4或Na 2 CO 3为基本添加剂,在室温下,一定范围内的末端链烯基膦酸酯被2-硝基苯磺酰肼(NBSH)生成的二酰亚胺有效还原。还证明了该方法具有较高的官能团耐受性。此外,我们的方法具有安全性高,反应条件温和,对设备的要求低以及化学选择性高的特点。
The first palladium‐catalyzed method for the arylation of α‐phosphonovinyl nonaflates is described. Using a catalyst comprised of Pd(OAc)2 and SPhos, terminal and internal α‐aryl vinylphosphonates could be efficiently accessed under mild conditions. The reaction features a broad coupling partner scope and tolerates many functional groups.
General Access to <i>C</i>-Centered Radicals: Combining a Bioinspired Photocatalyst with Boronic Acids in Aqueous Media
作者:Maheshwerreddy Chilamari、Jacob R. Immel、Steven Bloom
DOI:10.1021/acscatal.0c03422
日期:2020.11.6
indispensable building blocks for modern synthetic chemistry. In recent years, visible light photoredox catalysis has become a promising avenue to access C-centered radicals from a broad array of latent functional groups, including boronic acids. Herein, we present an aqueous protocol wherein water features a starring role to help transform aliphatic, aromatic, and heteroaromatic boronic acids to C-centered
Pd-Catalysed Suzuki coupling of α-bromoethenylphosphonates with organotrifluoroborates: a general protocol for the synthesis of terminal α-substituted vinylphosphonates
and robust protocol for the synthesis of terminal α-substituted vinylphosphonates via Suzuki coupling of α-bromovinylphosphonates with organotrifluoroborates has been successfully developed. This method features broad substrate scope, great functional group compatibilities, and easy scale-up ability. In addition to easy access of nucleophiles, straightforwardsynthesis of electrophiles was also realized
A Palladium-Catalyzed Decarboxylative Heck-Type Reaction of Disubstituted Vinylphosphonates in the Stereoselective Synthesis of Trisubstituted Vinylphosphonates
作者:Linjing Ren、Maogang Ran、Jiaxin He、Dan Xiang、Feng Chen、Peijun Liu、Chunyang He、Qiuli Yao
DOI:10.1002/ejoc.201900810
日期:2019.9.8
We describe a highly stereoselective and atomically economical approach for the preparation of trisubstituted vinylphosphonates through palladium‐catalyzed decarboxylative Heck‐type reactions of vinylphosphonates. Excellent E/Z selectivity was achieved mostly with E‐isomers with oxygen in the air was the sole oxidant; this was difficult to achieve via traditional methods. This work is the first example
An unprecedented approach toward synthesis of α-substituted ethylphosphonates based on CuH-catalyzed conjugate reduction of vinylphosphonates has been successfully developed. This protocol features mild conditions, broad substrate scope, good functional group compatibility, high overall efficiencies, and easy gram-scale synthesis. The Cu-catalyzed reduction takes place in a highly selective manner