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
Rhenium‐Catalyzed Decarboxylative Tri‐/Difluoromethylation of Styrenes with Fluorinated Carboxylic Acid‐Derived Hypervalent Iodine Reagents
作者:Yin Wang、Yunhui Yang、Congyang Wang
DOI:10.1002/cjoc.201900296
日期:2019.12
Herein, unprecedented rhenium‐catalyzed decarboxylative oxytri‐/difluoromethylation and Heck‐type trifluoromethylation of styrenes have been developed by using hypervalent iodine(III) reagents derived from cheap, stable, and easy‐handling fluorinated carboxylic acids. Mechanistic studies revealed a radical decarboxylative trifluoromethylation pathway occurring in these reactions.
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.
Synthesis of α-vinylphosphonates from terminal alkynes and H-phosphonates as only the Markovnikov-regioisomer under metal- and solvent-free conditions.
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