The synthetic preparation of naturally-occurring aromatase inhibitors, morachalcone A, isogemichalcone B, and isogemichalcone C
摘要:
A convergent synthesis applicable to the preparation of oxidized prenylchalcones is reported that relies on key Claisen-Schmidt, Mitsunobu, and vinyl/benzyl Stille coupling operations. The synthetic strategy was applied towards the preparation of the natural products morachalcone A and isogemichalcones B & C, allowing their preparation in less than 10 steps and 6-8% overall yield. (C) 2013 Elsevier Ltd. All rights reserved.
Palladium-catalyzed carbonylation of 2,4-enyne carbonates in an alcohol and under balloon pressure of CO proceeds through 1,5-substitution to yield (E)-2,3,5-trienoates. The olefin geometry of the substrate is important to control the overall stereochemistry of this alkoxycarbonylation method. The reaction proceeds through successive formation of π-allylpalladium with an R3 group oriented syn and σ-allenyl
of highly elaborate intermediates. For macrocyclization, both an HWE reaction and a Heck coupling were successfully employed to close the 24-membered macrolactone. During the synthetic campaign, a generally useful protocol for an E-selective Heck reaction of nonactivated alkenes and a method for the direct nucleophilic displacement of the Abiko−Masamune auxiliary with sterically hindered nucleophiles
Subtle but distinctive: The stereostructure of the biologically highly promising antimitoticagentleiodermatolide was uncertain. A short, efficient, and flexible totalsynthesis based on ring‐closing alkyne metathesis as the key step has now solved the puzzle. Subtle differences in the 1H NMR spectra of the structure shown and the conceivable isomer proved invaluable for the assignment.
微妙但与众不同:生物学上很有前途的抗有丝分裂剂leiodermatolide的立体结构尚不确定。以开环炔烃复分解为关键步骤的短而有效且灵活的全合成方法现已解决了这个难题。所示结构和可能的异构体在1 H NMR光谱中的细微差异证明对于该赋值是无价的。
Leiodermatolide derivatives and their use
申请人:Studiengesellschaft Kohle mbH
公开号:EP3012257A1
公开(公告)日:2016-04-27
The present invention refers to leiodermatolide derivatives and the use thereof as cytotoxic agents, in particular in the form of ADC s.
Selective Ni-catalyzed cross-electrophile coupling of alkynes, fluoroalkyl halides, and vinyl halides
作者:Yubei Dai、Fang Wang、Shengqing Zhu、Lingling Chu
DOI:10.1016/j.cclet.2021.12.050
日期:2022.8
We report a Ni-catalyzed three-component cross-electrophile coupling of alkynes with alkenyl halides and fluoroalkyl halides to generate fluoroalkyl-incorporated 1,3-dienes. This mild and operationally simple protocol is distinguished by its broad substrate scope and excellent chemo-, regio-, and stereo-selectivity, offering a new and organometallic agent-free platform for the construction of fluo
我们报道了一种 Ni 催化的炔烃与烯基卤化物和氟代烷基卤化物的三组分交叉亲电偶联,以生成掺有氟代烷基的 1,3-二烯。这种温和且操作简单的协议以其广泛的底物范围和出色的化学、区域和立体选择性而著称,为构建含氟烷基的二烯基序提供了一个新的无有机金属试剂平台。已经进行了初步的机理研究以探索潜在的反应途径。