Visible-Light-Induced C–O Bond Formation for the Construction of Five- and Six-Membered Cyclic Ethers and Lactones
作者:Honggu Im、Dahye Kang、Soyeon Choi、Sanghoon Shin、Sungwoo Hong
DOI:10.1021/acs.orglett.8b03166
日期:2018.12.7
Visible-light-induced intramolecular C–O bond formation was developed using 2,4,6-triphenylpyrylium tetrafluoroborate (TPT), which allows the regiocontrolled construction of cyclic ethers and lactones. The reaction is likely to proceed through the single-electron oxidation of the phenyl group, followed by the formation of a benzylic radical, thus preventing a competing 1,5-hydrogen abstraction pathway
bond arylation of benzyl ethers with Knochel-type arylzinc reagents has been developed. This transition-metal-catalyst-free reaction proceeds well under mild conditions in a simple and effective manner and enables the synthesis of a wide range of potentially biologically active benzyl ethers by using highly functionalized organozincreagents as a carbon nucleophile.
Structurally Diverse α-Substituted Benzopyran Synthesis through a Practical Metal-Free C(sp<sup>3</sup>)–H Functionalization
作者:Wenfang Chen、Zhiyu Xie、Hongbo Zheng、Hongxiang Lou、Lei Liu
DOI:10.1021/ol503004a
日期:2014.11.21
A trityl ion-mediated practical C–H functionalization of a variety of benzopyrans with a wide range of nucleophiles (organoboranes and C–H molecules) at ambient temperature has been disclosed. The metal-free reaction has an excellent functional group tolerance and high chemoselectivity and displays a broad scope with respect to both benzopyran and nucleophile partners, efficiently affording a collection
Direct oxidative C(sp3) H cyanation of secondary benzylic ethers
作者:Zehua Wang、Ying Mao、Honghao Guan、Min Cao、Jing Hua、Lei Feng、Lei Liu
DOI:10.1016/j.cclet.2019.03.019
日期:2019.6
Abstract Current studies on the oxidativeCH functionalization of benzylic ethers for CC forging process dominantly focus on primary ethers. The corresponding reaction of secondary ethers remains underdeveloped. Herein, a practical and efficientoxidativeCH cyanation of secondary benzylic ethers with TMSCN in the presence of DDQ is described. The metal-free process is well tolerated with a wide
Simple and Direct sp<sup>3</sup> C–H Bond Arylation of Tetrahydroisoquinolines and Isochromans via 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone Oxidation under Mild Conditions
作者:Wataru Muramatsu、Kimihiro Nakano、Chao-Jun Li
DOI:10.1021/ol401534g
日期:2013.7.19
The 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated sp3C–Hbondarylation of tetrahydroisoquinolines and isochromans is described. The corresponding products were facilely synthesized via a simple nucleophilic addition reaction between readily available aryl Grignard reagents and iminium (or oxonium) cations generated in situ by DDQ oxidation of tetrahydroisoquinolines (or isochromans) under