Lewis Acid Catalyzed Tandem 1,4-Conjugate Addition/Cyclization of in Situ Generated Alkynyl <i>o</i>-Quinone Methides and Electron-Rich Phenols: Synthesis of Dioxabicyclo[3.3.1]nonane Skeletons
作者:Ji-Yuan Du、Yan-Hua Ma、Fan-Xiao Meng、Bao-Li Chen、Shao-Liang Zhang、Qian-Li Li、Shu-Wen Gong、Da-Qi Wang、Chun-Lin Ma
DOI:10.1021/acs.orglett.8b01862
日期:2018.7.20
A versatile Lewis acid catalyzed tandem cyclization of in situgenerated alkynyl o-quinone methides (o-AQMs) with electron-rich phenols has been developed on the basis of the mode involving an intermolecular 1,4-conjugate addition/6-endo cyclization/1,3-aryl shift/intramolecular 1,4-conjugate addition cascade. This reaction provides a new method for expeditious assembly of synthetically and biologically
Metal-Free One-Pot Synthesis of 3-Phosphinoylbenzofurans via Phospha-Michael Addition/Cyclization of H-Phosphine Oxides and <i>in Situ</i> Generated <i>ortho-</i>Quinone Methides
A novel metal-free one-pot protocol for the effective and efficient synthesis of 3-phosphinoylbenzofurans via a phospha-Michael addition/cyclization of H-phosphine oxides and in situ generated ortho-quinone methides is described. Based on the expeditious construction of C(sp2)–P bonds, asymmetricsynthesis of optically pure 3-phosphinoylbenzofurans containing chiral P-stereogenic center has also been
描述了一种新颖的无金属一锅方案,该方案通过H-膦氧化物的磷化-迈克尔加成/环化作用和原位生成的邻醌甲基化物来有效和高效地合成3-膦酰基苯并呋喃。基于C(sp 2)-P键的快速构建,还通过使用手性R P -(-)-薄荷基苯基膦氧化物探索了含手性P-立体异构中心的光学纯3-膦酰基苯并呋喃的不对称合成。
Cu(OAc)<sub>2</sub>·H<sub>2</sub>O-Promoted Tandem β-Alkynyl Elimination of α- or β-Hydroxy Propargylic Alcohols and Homocoupling of the Resulting Alkynyl Species
作者:Xiangsheng Xu、Zhenyong Huang、Yanfeng Lu
DOI:10.3184/174751913x13739011239995
日期:2013.9
α or β-hydroxy propargylic alcohols undergo tandem C(sp)–C(sp3) bondcleavage via β-alkynyl elimination and homo-coupling of the resulted alkynyl species in the presence of Cu(OAc)2·H2O to produce the corresponding hydroxycarbonyl compounds and 1,3-butadiynes.
One Pot Synthesis of γ-Benzopyranones via Iron-Catalyzed Aerobic Oxidation and Subsequent 4-Dimethylaminopyridine Catalyzed 6-<i>endo</i>
Cyclization
作者:Di Zhai、Lingzhu Chen、Minqiang Jia、Shengming Ma
DOI:10.1002/adsc.201700993
日期:2018.1.4
One-potsynthesis of γ-benzopyranones was realized in decent yields and excellent regioselectivities via iron-catalyzed aerobic oxidation and 4-dimethylaminopyridine-catalyzed cyclization of related propargylic alcohols. Derivatizations to aromatic substituted γ-benzopyranones and synthesis of naturally occurring 3′,4′-dimethoxyflavone have also been realized.
Versatile and Expeditious Synthesis of Aurones via Au<sup>I</sup>-Catalyzed Cyclization
作者:Hassina Harkat、Aurélien Blanc、Jean-Marc Weibel、Patrick Pale
DOI:10.1021/jo702197b
日期:2008.2.1
Aurones are conveniently formed in a three-step procedure including a goldI-catalyzed cyclization of 2-(1-hydroxyprop-2-ynyl)phenols as a highly regio- and stereoselective key step. A wide diversity of derivatives can be obtained starting from substituted salicylaldehydes. Synthesis of natural 4,6,3‘,4‘-tetramethoxyaurone and structure revision of two natural products (dalmaisione D and 4‘-chloroaurone)