1,3,5-Triaza-7-phosphaadamantane (PTA): A Practical and Versatile Nucleophilic Phosphine Organocatalyst
作者:Xiaofang Tang、Bo Zhang、Zhengrong He、Ruili Gao、Zhengjie He
DOI:10.1002/adsc.200700071
日期:2007.8.6
cycloaddition reaction of 4-substituted 2,3-butadienoates with N-tosylimines, PTA is also proven to be a comparable catalyst as tributylphosphine (PBu3). By systematic comparison with other structurally similar N,P catalysts, it is concluded that the superiority of PTA in the above nucleophilic catalysis is attributable to its comparable nucleophilicity with that of trialkylphosphines. The feasibility
An Improved Protocol for the Morita‐Baylis‐Hillman Reaction Allows Unprecedented Broad Synthetic Scope
作者:Nilton S. Camilo、Hugo Santos、Lucas A. Zeoly、Fábio S. Fernandes、Manoel T. Rodrigues、Thiago S. Silva、Samia R. Lima、José Cláudio Serafim、Aline S. B. de Oliveira、Arthur G. Carpanez、Giovanni W. Amarante、Fernando Coelho
DOI:10.1002/ejoc.202101448
日期:2022.3.7
By the combination of DABCO and aceticacid under solvent-free conditions, the Morita-Baylis-Hillman reaction rate of both activated and non-activated aldehydes increased significantly. The disclosed procedure is operationally simple and is compatible with a wide array of both nucleophilic and electrophilic reaction partners.
2,6-Diphenyl-4H-chalcogenopyran-4-ones and 2,6-diphenyl-4H-chalcogenopyran-4-thione a new series of catalysts for the Baylis-Hillman reaction, were investigated. The reactions proceeded smoothly in the presence of 1 mol eq. of TiCl4 under atmospheric pressure at 0 degrees C, giving adducts in moderate to high yields. Chalcogenopyranones and chalcogenopyranthiones were a more efficient kind of catalyst than Me2S. (C) 1999 Elsevier Science Ltd. All rights reserved.
New Efficient Synthesis of 1,2,4-Trisubstituted Furans by a Sequential Passerini/Wittig/Isomerization Reaction Starting from Baylis–Hillman β-Bromo Aldehydes
作者:Ming-Wu Ding、Zhi-Lin Ren、Mei Sun、Zhi-Rong Guan
DOI:10.1055/s-0036-1588564
日期:2018.1
A new and efficient synthesis of 1,2,4-trisubstituted furans from a Baylis–Hillman β-bromo aldehyde, an acid, an isocyanide, and methyl(diphenyl)phosphine, by a sequential Passerini condensation, Wittig reaction, and isomerization in the presence of triethylamine is reported.
A short approach toward new acrolein‐type derivatives, functionalized in position 2 is described. It involves, as the key step, a smooth transformation of acylsilanes into aldehydes by irradiation in water‐organic solvent mixtures. The functionalized enals obtained by this newroute appear as versatile building blocks for the preparation of natural products and/or bioactive compounds.