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
Copper(II) catalyzed cross-dehydrogenative coupling of cyclic benzylic ethers with a variety of simple carbonyl compounds mediated by Na2S2O8 is developed. The scope of carbonyl components is broad, including simple aldehydes as well as ketones. The use of Na2S2O8 as the oxidant for the CDC reaction is attractive based on economical and environmental factors.
开发了铜(II)催化的环状苄醚与各种由Na 2 S 2 O 8介导的简单羰基化合物的交叉脱氢偶联。羰基成分的范围很广,包括简单的醛以及酮。基于经济和环境因素,使用Na 2 S 2 O 8作为CDC反应的氧化剂是有吸引力的。
Catalytic Enantioselective Oxidative Cross-Coupling of Benzylic Ethers with Aldehydes
作者:Zhilin Meng、Shutao Sun、Huiqing Yuan、Hongxiang Lou、Lei Liu
DOI:10.1002/anie.201308701
日期:2014.1.7
The first one‐pot enantioselectiveoxidative coupling of cyclic benzylicethers with aldehydes has been developed. A variety of benzylicethers were transformed into the corresponding oxygen heterocycles with high enantioselectivity. Mechanistic experiments were conducted to determine the nature of the reaction intermediates. The application of this strategy to coupling reactions with other nucleophiles
Catalyzed Selective Direct α- and γ-Alkylation of Aldehydes with Cyclic Benzyl Ethers by Using T+BF4− in the Presence of an Inexpensive Organic Acid or Anhydride
作者:Heinrich Richter、Renate Rohlmann、Olga García Mancheño
DOI:10.1002/chem.201101786
日期:2011.10.4
The cross dehydrogenative coupling (CDC) of cyclicbenzylethers with aliphatic and α,β‐unsaturated aldehydes has been developed. The mild reaction conditions, in which an N‐oxoammonium salt derived from TEMPO (2,2,6,6‐tetramethyl‐1‐piperidinoxyl) is employed as the oxidant in combination with a Cu catalyst, allow the use of relatively redox‐unstable aldehydes under oxidative CDC conditions. The addition