The electrosynthesis of 2-vinylidene-3-yne carboxylic acids from carbon dioxide and substituted 1,3-diynes is catalysed by a nickel–triamine complex and results in a regio- and stereo-selective addition to one triple bond.
Regioselective Synthesis of 2,3‐Dihydrobenzo[
<i>f</i>
]isoindolones via Ag‐Catalyzed Sequential Ugi 4CR/Cascade Radical Cyclization Reaction
作者:Ying‐Chun He、Yan‐Mei Yan、Zhen‐Xing Ren、Yong‐Zhao Wang、Qiang Yu、Jun Xiong、Meng‐Liang Wang
DOI:10.1002/adsc.202001255
日期:2021.2.16
An approach to 2,3‐dihydrobenzo[f]isoindolones by a Ag‐catalyzedUgi4CR/cascaderadicalcyclization sequence under mild conditions has been developed. The reaction of (E)‐2‐benzylidene‐4‐arylbut‐3‐ynoic acids, aldehydes, amines, and isocyanides produced 2,3‐dihydro‐benzo[f]isoindolonesregioselectively in 60–85% yields viasequentialUgi4CR/cascaderadicalcyclizationreaction in the presence of
已经开发了一种在温和条件下通过Ag催化的Ugi 4CR /级联自由基环化序列制备2,3-二氢苯并[ f ]异吲哚酮的方法。(E)-2-亚苄基-4-芳基丁-3-炔酸,醛,胺和异氰酸酯的反应通过连续的Ugi 4CR /选择性地产生60-85%的2,3-二氢苯并[ f ]异吲哚酮。 Cs 2 CO 3和AgOTf存在下进行级联自由基环化反应 该方法以一锅法在空气气氛下实现了两个C-C键的形成。
Activation of carbon dioxide: nickel-catalyzed electrochemical carboxylation of diynes
作者:Sylvie Derien、Jean Claude Clinet、Elisabet Dunach、Jacques Perichon
DOI:10.1021/jo00061a038
日期:1993.4
The simultaneous activation of carbon dioxide and diynes by electrogenerated LNi(0) complexes (L = bpy, pentamethyldiethylenetriamine: PMDTA) enables the selective incorporation of one molecule of CO2 into the unsaturated systems and the preparative-scale electrosyntheses of carboxylic acids. A series of nonconjugated diynes afforded selectively linear or cyclic adducts depending on the ligand. Diynes bearing both a terminal and an internal triple bond gave exclusive CO2 incorporation into the terminal alkynyl group, regioselectively at the 2-position. The electrocarboxylation of 1,3-diynes with the Ni-PMDTA catalytic system yielded, regio- and stereoselectively, (E)-2-vinylidene-3-yne carboxylic acids in one step. The electrosyntheses were carried out in single-compartment cells fitted with a consumable magnesium anode, and utilized a catalytic amount of an air-stable Ni(II) complex as the catalyst precursor. Cyclic voltammetry studies revealed that both carbon dioxide and the diynes are able to coordinate to LNi(0)-generated species in DMF.
Studies on the transition metal-catalyzed synthesis of variously substituted (E)-3-[1-(aryl)methylidene]- and (E)-3-(1-alkylidene)-3H-furan-2-ones
5-Aryl and 5-alkyl substituted (E)-3-[1-(aryl)methylidene]- and (E)-3-(1-alkylidene)-3H-furan-2-ones, (E)-9, have been selectively synthesized by cyclization of the corresponding (E)-2-(1-alkynyl)-3-aryl/alkylpropenoic acids, (E)-11, in the presence of AgNO3 or Pd-catalysts such as trans-di(μ-acetato)bis[(di-o-tolylphosphino)benzyl]dipalladium(II) or that constituted of a mixture of Et3N and PdCl2(PhCN)2
One-pot and regioselective synthesis of functionalized γ-lactams via a metal-free sequential Ugi 4CR/Intramolecular 5-exo-dig cyclization reaction
作者:Yan-Mei Yan、Meng-Liang Wang、Yu-Long Liu、Ying-Chun He
DOI:10.1016/j.tet.2020.131389
日期:2020.8
A new one-pot and regioselectivesynthesis of functionalized γ-lactams by a metal-free Ugi 4CR/intramolecular 5-exo-dig cyclization sequence under mild conditions has been developed. The reaction of propenoic acids, aldehydes, amines, and isocyanides produced γ-lactams regioselectively in 72–89% yields via sequential Ugi 4CR/intramolecular 5-exo-dig cyclization reaction in the presence of Cs2CO3.
一种新的单釜和官能化的区域选择性合成γ由无金属的Ugi 4CR /分子内内酰胺5-外型-挖温和的条件下环化序列已经被开发出来。丙烯酸酸,醛,胺和异氰化物反应生成γ在72-89%的收率通过顺序的Ugi 4CR区域选择性内酰胺/分子内-5-外-挖中铯的存在下环化反应2 CO 3。