Visible-Light-Promoted Redox-Neutral Cyclopropanation Reactions of α-Substituted Vinylphosphonates and Other Michael Acceptors with Chloromethyl Silicate as Methylene Transfer Reagent
with chloromethyl silicate as a methylene transfer reagent has been accomplished via visible‐light‐mediated redox‐neutral catalysis. This method features broad functional group tolerance and mild conditions. In addition to α‐substituted vinylphosphonates, a range of Michael acceptors including α,β‐unsaturated acrylate, ketone, amide and sulfone are suitable substrates for this photocatalytic cyclopropanation
α-Phosphonovinyl Arylsulfonates: An Attractive Partner for the Synthesis of α-Substituted Vinylphosphonates through Palladium-Catalyzed Suzuki Reactions
A new and attractive coupling partner for the synthesis of α‐substituted vinylphosphonates through Suzuki reactions has been developed. The developed O‐centered electrophiles couple with various organoboron reagents to give α‐substituted vinylphosphonates in moderate to excellent yields. This protocol features broad substrate scope, mild conditions, and high efficiency.
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.
A simple and straightforward method for the synthesis of α-substituted ethylphosphonates via diimide reduction strategy is described. With K3PO4 or Na2CO3 as the basic additive, a range of terminal alkenylphosphonates underwent efficient reduction by diimide generated from 2-nitrobenzenesulfonylhydrazide (NBSH) under room temperature. The high functional group tolerance of this methodology is also
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。
Efficient synthesis of α-substituted ethylphosphonates via CuH-catalyzed conjugate reduction of terminal alkenylphosphonate
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