Sunlight-Driven Decarboxylative Alkynylation of α-Keto Acids with Bromoacetylenes by Hypervalent Iodine Reagent Catalysis: A Facile Approach to Ynones
作者:Hui Tan、Hongji Li、Wangqin Ji、Lei Wang
DOI:10.1002/anie.201503479
日期:2015.7.13
A novel and practical decarboxylativealkynylation of α‐keto acids with bromoacetylenes is catalyzed by hypervalent iodine(III) reagents when irradiation by sunlight at room temperature. The product ynones are generated in good yields. Experiments show that results obtained with blue light (λ=450–455 nm) are comparable to those obtained when using sunlight. Mechanistic studies demonstrate that the
A transition-metal-free synthetic method of various ynones via decarboxylative alkynylation of α-keto acids is described. The reaction is carried out undermildconditions and exhibits remarkable tolerance of functional groups. The mechanism of a radical process is proposed in the reaction.
Dual Hypervalent Iodine(III) Reagents and Photoredox Catalysis Enable Decarboxylative Ynonylation under Mild Conditions
作者:Hanchu Huang、Guojin Zhang、Yiyun Chen
DOI:10.1002/anie.201502369
日期:2015.6.26
combination of hypervalentiodine(III) reagents (HIR) and photoredoxcatalysis with visible light has enabled chemoselective decarboxylativeynonylation to construct ynones, ynamides, and ynoates. This ynonylation occurs effectively undermild reaction conditions at room temperature and on substrates with various sensitive and reactive functional groups. The reaction represents the first HIR/photoredox dual
Metal-Free Iodosulfonylation of Internal Alkynes: Stereodefined Access to Tetrasubstituted Olefins
作者:Ravi Kumar、Vikas Dwivedi、Maddi Sridhar Reddy
DOI:10.1002/adsc.201700576
日期:2017.8.17
The stereoselective E‐iodosulfonylation of internalalkynes for synthesizing highly defined tetrasubstituted olefins using sodium phenyl sulfinate and iodine has been achieved. Most of the alkynes explored are non‐symmetrical and the regioselection is under full control. Arylalkynes with various electron‐withdrawing groups like keto, aldehyde, ester, amide, cyano, sulfone, bromo, chloro and iodo on
Synthesis of benzoxazoles <i>via</i> the copper-catalyzed hydroamination of alkynones with 2-aminophenols
作者:Kohei Oshimoto、Hiroaki Tsuji、Motoi Kawatsura
DOI:10.1039/c9ob00572b
日期:——
describe herein the synthetic method to benzoxazole derivatives via the copper-catalyzed hydroamination of alkynones with 2-aminophenols. The method produced a wide variety of functionalized benzoxazole derivatives in good yields. Preliminary mechanistic experiments revealed that the reaction would proceed through the copper-catalyzed hydroamination of alkynones and the sequential intramolecular cyclization