A Novel Route to Substituted Trienes and Tetraenes
摘要:
The reaction sequence involving Arbuzov rearrangement of allyl phosphites 4 to phosphonates 5 followed by Horner-Wadsworth-Emmons olefination of 5 with aldehydes gives substituted trienes and tetraenes 8 with full stereoselectivity.
Baylis–Hillman reaction in [bdmim][PF 6 ] ionic liquid
摘要:
A new use of ionic liquid [bdmim][PF6] as solvent for the Baylis-Hillman reaction is presented. Unlike the commonly used [bmim][PF6] that evidently reacts with electrophilic aldehydes under basic conditions, ionic liquid [bdmim][PF6] is inert and the Baylis-Hillman reaction in [bdmim][PF6] proceeds smoothly with better yield. (C) 2004 Elsevier Ltd. All rights reserved.
Terminating catalytic asymmetric Heck cyclizations by stereoselective intramolecular capture of η3-allylpalladium intermediates: total synthesis of (−)-spirotryprostatin B and three stereoisomers
作者:Larry E. Overman、Mark D. Rosen
DOI:10.1016/j.tet.2010.05.048
日期:2010.8
A catalytic intramolecular Heck reaction, followed by capture of the resulting η3-allylpalladium intermediate by a tethered diketopiperazine, is the central step in a concise synthetic route to (−)-spirotryprostatin B and three stereoisomers. This study demonstrates that an acyclic, chiral η3-allylpalladium fragment generated in a catalytic asymmetric Heck cyclization can be trapped by even a weakly
催化分子内 Heck 反应,然后通过束缚的二酮哌嗪捕获所得的 η 3 -烯丙基钯中间体,是 (-)-螺环前列腺素 B 和三种立体异构体的简洁合成路线中的核心步骤。该研究表明,在催化不对称 Heck 环化中产生的无环手性 η 3 -烯丙基钯片段,即使是弱亲核性的二酮哌嗪也可以比非对映体平衡更快地捕获。
Palladium-Catalyzed Regio- and Enantioselective Allylic Alkylation of Bis Allylic Carbonates Derived from Morita−Baylis−Hillman Adducts
作者:Barry M. Trost、Megan K. Brennan
DOI:10.1021/ol701585b
日期:2007.9.1
Morita-Baylis-Hillman diene adducts are used as substrates in the palladium-catalyzed asymmetric allylic alkylation reaction with oxygen and carbonnucleophiles in good regio- and enantioselectivity.
resulting η(3)-allylpalladium intermediate by a tethered diketopiperazine, is the central step in a concise synthetic route to (-)-spirotryprostatinB and three stereoisomers. This study demonstrates that an acyclic, chiral η(3)-allylpalladium fragment generated in a catalytic asymmetric Heck cyclization can be trapped by even a weakly nucleophilic diketopiperazine more rapidly than it undergoes diastereomeric
催化分子内 Heck 反应,随后通过束缚二酮哌嗪捕获所得的 η(3)-烯丙基钯中间体,是 (-)-spirotryprostatin B 和三种立体异构体的简明合成路线中的核心步骤。这项研究表明,在催化不对称 Heck 环化中生成的无环、手性 η(3)-烯丙基钯片段可以被甚至弱亲核性二酮哌嗪更快地捕获,而不是经历非对映体平衡。
A Novel Route to Substituted Trienes and Tetraenes
作者:Tomasz Janecki
DOI:10.1080/00397919308009822
日期:1993.3.1
The reaction sequence involving Arbuzov rearrangement of allyl phosphites 4 to phosphonates 5 followed by Horner-Wadsworth-Emmons olefination of 5 with aldehydes gives substituted trienes and tetraenes 8 with full stereoselectivity.
Baylis–Hillman reaction in [bdmim][PF 6 ] ionic liquid
作者:Jen-Chuah Hsu、Ya-Hew Yen、Yen-Ho Chu
DOI:10.1016/j.tetlet.2004.04.099
日期:2004.6
A new use of ionic liquid [bdmim][PF6] as solvent for the Baylis-Hillman reaction is presented. Unlike the commonly used [bmim][PF6] that evidently reacts with electrophilic aldehydes under basic conditions, ionic liquid [bdmim][PF6] is inert and the Baylis-Hillman reaction in [bdmim][PF6] proceeds smoothly with better yield. (C) 2004 Elsevier Ltd. All rights reserved.