Cyclic Iodine Reagents Enable Allylic Alcohols for Alkyl Boronate Addition/Rearrangement by Photoredox Catalysis
作者:Mingshang Liu、Hanchu Huang、Yiyun Chen
DOI:10.1002/cjoc.201800461
日期:2018.12
iodine(III) reagents enable the synthesis of cyclopentanones, cyclohexanones, and dihydrofuranones bearing α‐quaternary centers by photoredox catalysis. The reaction proceeds by the formation of the novel cyclic iodine(III) reagent‐allylic alcohol complex, which enables the first alkyl boronate addition and semi‐pinacol rearrangement of allylic alcohols with dual alcohol and olefin activation. The reaction
Asymmetric Chlorination/Ring Expansion for the Synthesis of α-Quaternary Cycloalkanones
作者:Qin Yin、Shu-Li You
DOI:10.1021/ol5005565
日期:2014.3.21
A highly enantioselective chlorination/ringexpansion cascade for the construction of cycloalkanones with an all-carbon quaternary center was realized (up to 97% ee). Oxa-cyclobutanol substrates were employed for the first time in the ringexpansionreactions, affording the functionalized dihydrofuranones in excellent enantioselectivity.
Metal-Free Oxidative Decarboxylative Acylation/Ring Expansion of Vinylcyclobutanols with<i>α</i>-Keto Acids by Visible Light Photoredox Catalysis
作者:Jin-Jiang Zhang、Yuan-Bo Cheng、Xin-Hua Duan
DOI:10.1002/cjoc.201600729
日期:2017.3
A metal‐free visible‐light‐mediated decarboxylative acylation/ring expansion of vinylcyclobutanols with α‐keto acids has been developed. Hypervalent iodine reagent was found to be important for promoting decarboxylation of α‐keto acids in this tandem radical process. This protocol has been successfully applied to synthesis of a variety of substituted 1,4‐dicarbonyl compounds and tolerated some functional
Enantioselective Catalytic Aldehyde α‐Alkylation/Semipinacol Rearrangement: Construction of α‐Quaternary‐δ‐Carbonyl Cycloketones and Total Synthesis of (+)‐Cerapicol
作者:Jie Yang、Xiao‐Ming Zhang、Fu‐Min Zhang、Shao‐Hua Wang、Yong‐Qiang Tu、Zhen Li、Xi‐Chao Wang、Hong Wang
DOI:10.1002/anie.202001100
日期:2020.5.25
An enantioselectivealdehyde α-alkylation/semipinacol rearrangement was achieved through organo-SOMO catalysis. The catalytically generated enamine radical cation serves as a carbon radical electrophile that can stereoselectively add to the alkene of an allylic alcohol and initiate ensuing ring-expansion of cyclopropanol or cyclobutanol. This tandem reaction enables the production of a wide range of
α-Quaternary Mannich Bases through Copper-Catalyzed Amination-Induced 1,2-Rearrangement of Allylic Alcohols
作者:Wei-Zhi Weng、Jian-Guo Sun、Ping Li、Bo Zhang
DOI:10.1002/chem.201702428
日期:2017.7.21
A novel copper‐catalyzed amination‐induced 1,2‐rearrangement reaction of allylic alcohols has been developed under simple and mild conditions. The commercially available N‐fluorobenzenesulfonimide (NFSI) is employed as an amination reagent. In this transformation, not only alkyl, but also aryl substituents can efficiently undergo 1,2‐carbon atom migration, thereby providing an efficient and powerful