A Two-Component Alkyne Metathesis Catalyst System with an Improved Substrate Scope and Functional Group Tolerance: Development and Applications to Natural Product Synthesis
作者:Sebastian Schaubach、Konrad Gebauer、Felix Ungeheuer、Laura Hoffmeister、Marina K. Ilg、Conny Wirtz、Alois Fürstner
DOI:10.1002/chem.201601163
日期:2016.6.13
standard catalyst 1 largely failed to effect the critical macrocyclization, whereas the two‐component system was fully operative. A study directed toward the quinolizidine alkaloid lythrancepine I features yet another instructive example, in that a triyne substrate was metathesized with the help of 3/11 such that two of the triple bonds participated in ring closure, while the third one passed uncompromised
Visible-Light-Mediated Photoredox-Catalyzed Regio- and Stereoselective Chlorosulfonylation of Alkynes
作者:Prashant Chakrasali、Kyuneun Kim、Young-Sik Jung、Hyejin Kim、Soo Bong Han
DOI:10.1021/acs.orglett.8b03273
日期:2018.12.7
Herein, a one-step chlorosulfonylation of alkynes via a photocatalytic redox process is described. A variety of commercially available sulfonylchlorides can be applied for the generation of sulfonyl radical species under visible-light irradiation. Regio- and stereoselective addition of the sulfonyl radical and chloride leads to the efficient formation of (E)-selective β-chlorovinyl sulfones from a
Alkyne metathesis with simple catalyst systems: High yield dimerization of propynylated aromatics; scope and limitations
作者:Neil Gregory Pschirer、Uwe H.F. Bunz
DOI:10.1016/s0040-4039(99)00282-8
日期:1999.3
yield dimerization of propynylated benzenes and propynylnaphthalene by a mixture of Mo(CO)6 and 4-chlorophenol at 140 °C in 1,2-dichlorobenzene is reported to give the corresponding disubstituted alkynes. The scope and limitation of the reaction and the influence of substitution pattern and substitution type are discussed. Oxygen or nitrogen carrying substrates metathesize in moderate to good yields
Robust Alkyne Metathesis Catalyzed by Air Stable d<sup>2</sup> Re(V) Alkylidyne Complexes
作者:Mingxu Cui、Wei Bai、Herman H. Y. Sung、Ian D. Williams、Guochen Jia
DOI:10.1021/jacs.0c06581
日期:2020.8.5
We report in this communication the first example of catalytic alkynemetathesisreactions mediated by well-defined non-d0 alkylidyne complexes. The air-stable d2 Re(V) alkylidyne complex Re4, bearing two PO-chelating ligands and a labile pyridine ligand, could catalyze homo-metathesis of internal alkynes with a broad substrate scope, including alcohols, amines and even carboxylic acids. The catalyst
我们在此通讯中报告了由明确定义的非 d0 烷炔配合物介导的催化炔复分解反应的第一个例子。空气稳定的 d2 Re(V) 亚烷基配合物 Re4,带有两个 PO 螯合配体和一个不稳定的吡啶配体,可以催化具有广泛底物范围的内炔的均位复分解,包括醇、胺甚至羧酸。该催化剂在固体和溶液状态下都可以耐受加热、空气和水分,催化复分解反应可以在湿溶剂中正常进行。
Multicomponent Oxidative Trifluoromethylation of Alkynes with Photoredox Catalysis: Synthesis of α-Trifluoromethyl Ketones
作者:Yashwardhan R. Malpani、Bishyajit Kumar Biswas、Hong Sik Han、Young-Sik Jung、Soo Bong Han
DOI:10.1021/acs.orglett.8b00410
日期:2018.4.6
oxidative addition of CF3 and H2O to alkynes was achieved with photoredoxcatalysis to obtain α-trifluoromethyl ketones via rapid enol-keto tautomerization. The reaction exhibits high functional group tolerance and regioselectivity. Heterocycles of various sizes containing CF3 were synthesized from the α-CF3-substituted diketones obtained through the protocol, thereby demonstrating the versatile applicability