An unexpected rearrangement-hydration reaction sequence of 2H-chromenes to dihydrochalcones under catalysis of HAuCl4
摘要:
2-Aryl-2H-chromenes in aqueous DCM medium under catalysis of HAuCl4 are converted into 3-(2-hydroxyaryl)-1-arylpropan-1-ones through hydration-rearrangement reaction sequence in very good yield. The key step probably involves the [1,5] hydride shift followed by the hydrolysis under the reaction condition. The notable advantages of this method are operational simplicity and ease of isolation of products and also provide a pathway to convert the chalcone into DHCs with the transposition of carbonyl group. (C) 2012 Elsevier Ltd. All rights reserved.
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
Iron-Catalyzed Rearrangements and Cycloaddition Reactions of 2<i>H</i>-Chromenes
作者:Yi Luan、Huan Sun、Scott E. Schaus
DOI:10.1021/ol202772k
日期:2011.12.16
Iron(III) salts catalyze the tandem rearrangement/hetero-Diels-Alder reaction of 2H-chromenes to yield tetrahydrochromeno heterocycles. The process can occur as a homodimerization and cycloaddition process using electron-rich dienophiles. Deuterium labeling and mechanistic studies revealed a hydride shift and ortho-quinone methide cycloaddition reaction pathway.
Subramanian, R. Sankara; Balasubramanian, K. K., Synthetic Communications, 1989, vol. 19, # 7,8, p. 1255 - 1260
作者:Subramanian, R. Sankara、Balasubramanian, K. K.
DOI:——
日期:——
SUBRAMANIAN, RAJARAM SANKARA;BALASUBRAMANIAN, KALPATTU KUPPUSAMY, TETRAHEDRON. LETT., 29,(1988) N 51, C. 6797-6800