Fluorinative Rearrangements of Substituted Phenylallenes Mediated by (Difluoroiodo)toluene: Synthesis of α-(Difluoromethyl)styrenes
作者:Zhensheng Zhao、Léanne Racicot、Graham K. Murphy
DOI:10.1002/anie.201706798
日期:2017.9.11
(difluoroiodo)toluene in the presence of 20 mol % BF3⋅OEt2 to yield α‐difluoromethyl styrenes. This unprecedented reaction was entirely chemoselective for the internal allene π bond, and showed remarkable regioselectivity during the fluorination event. Substituted phenylallenes, phenylallenes possessing both phenyl‐ and α‐allenyl substituents, and diphenylallenes were investigated, and good functional‐group
Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of <i>vicinal</i>-dichlorides and chlorodienes
作者:Zhensheng Zhao、Graham K Murphy
DOI:10.3762/bjoc.14.67
日期:——
Allyl and vinyl chlorides represent important structural motifs in organic chemistry. Herein is described the chemoselective and regioselective reaction of aryl- and α-substituted phenylallenes with the hypervalent iodine (HVI) reagent 1-chloro-1,2-benziodoxol-3-one. The reaction typically results in vicinal dichlorides, except with proton-containing α-alkyl substituents, which instead give chlorinated
The synthesis of regio- and stereoselective arylsubstitutedα,β-unsaturated aldehydes and ketones from activated allenes was achieved. This mild and non-metallic oxidation is exclusively driven by benign ambient air and triggered by visible light. The same starting materials under ideal anaerobic conditions led to the 2,3-diphenylselenation adduct with no trace of oxygenated products, demonstrating
Dual Photoredox and Nickel Catalysis in Regioselective Diacylation: Exploring the Versatility of Nickel Oxidation States in Allene Activation
作者:Shrikant D. Tambe、Ho Seong Hwang、Eunhui Park、Eun Jin Cho
DOI:10.1021/acs.orglett.4c01373
日期:2024.5.17
regioselective radical diacylation of allenes with ketoacids to produce 1,4-dione products by dual photoredox and nickel catalysis. This integrated approach merges redox-active oxidative addition and reductive elimination steps with migratory insertion. The acyl radical generated in the photoredoxcycle sequentially adds to Ni(I) and Ni(II) intermediates following a Ni(I)–Ni(II)–Ni(II)–Ni(III)–Ni(I) catalytic
Visible-light-promoted hydrocarboxylation of allenes with formate salt and CO2 was developed for the first time using commercially available [Ir(ppy)2(dtbbpy)]PF6 as a photocatalyst. This strategy provides an efficient and practical method to access β,γ-unsaturated linear carboxylic acids in moderate yields with complete regioselectivity.