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
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.
Lewis Acid Enables Ketone Phosphorylation: Synthesis of Alkenyl Phosphonates
作者:Xiao‐Hong Wei、Chun‐Yuan Bai、Lian‐Biao Zhao、Ping Zhang、Zhen‐Hua Li、Yan‐Bin Wang、Qiong Su
DOI:10.1002/cjoc.202100083
日期:2021.7
efficient Lewis acid enabled ketones phosphonylation to synthesize vinylphosphonates has been developed. This method relays on ketone hydrophosphonylation/α-hydroxy phosphonates unimolecular elimination (E1) dehydration cascade reaction sequence. Various C—P bond formation products were obtained in moderate to excellent yields with water as the only byproduct in the reaction.
new bifunctional C1 synthon: With bromomethyl silicate as a CH2 source, visible‐light‐induced cyclopropanation has been demonstrated to be amenable to the alkenes including Michael acceptors, styrene derivatives, and unactivated 1,1‐dialkyl ethylenes. In addition to the broad substrate scope, this radical‐polar crossover process is also characterized by its redox‐neutral process, mild conditions, and