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
Zeolite-catalyzed simple synthesis of isochromans via the oxa-Pictet–Spengler reaction
作者:Adrienn Hegedüs、Zoltán Hell
DOI:10.1039/b601314g
日期:——
The modified small pore size zeolite E4a has been found to be an efficient catalyst for the synthesis of isochromans via the oxa-PictetâSpengler reaction. This method is simple, cheap, environmentally-friendly and gives the isochromans in high yield.
Transition-Metal-Free Cross-Coupling of Indium Organometallics with Chromene and Isochroman Acetals Mediated by BF<sub>3</sub>·OEt<sub>2</sub>
作者:José M. Gil-Negrete、José Pérez Sestelo、Luis A. Sarandeses
DOI:10.1021/acs.orglett.6b02058
日期:2016.9.2
coupling of triorganoindiumreagents with benzopyranyl acetals mediated by a Lewis acid has been developed. The reaction of R3In with chromene and isochroman acetals in the presence of BF3·OEt2 afforded 2-substituted chromenes and 1-substituted isochromans, respectively, in good yields. The reactions proceed with a variety of triorganoindiumreagents (aryl, heteroaryl, alkynyl, alkenyl, alkyl) using