Linear Conjugated Systems Bearing Aromatic Terminal Groups. III. The Synthesis and the Electronic Spectra of 1,1′-Dinaphthyl- and 2,2′-Dinaphthylpoly-ynes
Linear Conjugated Systems Bearing Aromatic Terminal Groups. III. The Synthesis and the Electronic Spectra of 1,1′-Dinaphthyl- and 2,2′-Dinaphthylpoly-ynes
Copper-Catalyzed Three-Component Synthesis of 3-Aminopyrazoles and 4-Iminopyrimidines via β-Alkynyl-<i>N</i>-sulfonyl Ketenimine Intermediates
作者:Yanpeng Xing、Binyu Cheng、Jing Wang、Ping Lu、Yanguang Wang
DOI:10.1021/ol502302w
日期:2014.9.19
4-iminopyrimidines were efficiently prepared via copper-catalyzedthree-componentreactions of butadiynes, sulfonylazides, and hydrazides or imidamides. The reactions were regioselectively approached via the formation of a β-alkynyl-N-sulfonyl ketenimine intermediate which represented a new and effective 1,3-dielectrophilic equivalent in organic synthesis.
Aerobic Dimerization of Enediyne Compounds: Construction of Naphthalene Frameworks
作者:Dongxu Wang、Fei Ling、Xiang Liu、Zexiang Li、Cheng Ma
DOI:10.1002/chem.201504085
日期:2016.1.4
annulation of enediynecompounds leading to naphthaleneframeworks has been developed by using Pd(OAc)2 as the catalyst in the presence of NaI under O2 (1 atm). This reaction provided efficient access to a class of symmetric core‐annulated naphthalenes by the homoannulation of enediyne–imides. Intriguingly, the crossover annulation of enediyne–imides and other functionalized enediynes could also be
Cyclobutene vs 1,3-Diene Formation in the Gold-Catalyzed Reaction of Alkynes with Alkenes: The Complete Mechanistic Picture
作者:M. Elena de Orbe、Laura Amenós、Mariia S. Kirillova、Yahui Wang、Verónica López-Carrillo、Feliu Maseras、Antonio M. Echavarren
DOI:10.1021/jacs.7b03005
日期:2017.8.2
The intermoleculargold(I)-catalyzed reaction between arylalkynes and alkenes leads to cyclobutenes by a [2 + 2] cycloaddition, which takes place stepwise, first by formation of cyclopropyl gold(I) carbenes, followed by a ring expansion. However, 1,3-butadienes are also formed in the case of ortho-substituted arylalkynes by a metathesis-type process. The corresponding reaction of alkenes with aryl-1
芳基炔烃与烯烃之间的分子间金(I)催化反应通过[2 + 2]环加成反应逐步生成环丁烯,该过程逐步进行,首先形成环丙基金(I)卡宾,然后进行环扩环。但是,在邻位的情况下也会形成1,3-丁二烯复分解型方法取代了芳基炔烃。烯基与芳基炔烃对应的烯烃与芳基-1,3-丁二炔的相应反应仅产生环丁烯。在密度泛函理论计算的基础上,提出了炔烃与烯烃的金(I)催化反应的综合机理,表明生成环丁烯或二烯的两条途径的能量非常接近。关键中间体是环丙基金(I)卡宾,它们是通过逆向布赫纳反应从立体定义的1a,7b-二氢-1 H-环丙烷[ a ]萘独立生成的。
Catalytic Enantioselective 1,2-Addition of Terminal 1,3-Diynes to Trifluoromethyl Ketones
作者:Yan Zheng、Hai Ma、Jun-An Ma
DOI:10.1002/cjoc.201500901
日期:2016.5
A facile catalyticenantioselective 1,2‐addition of diynes to trifluoromethyl ketones was developed. By a combination of Me2Zn, Ti(OPr‐i)4, BaF2 and quinine, the reaction of a series of terminal diynes with trifluoromethyl ketones proceeded to afford trifluoromethylated chrial tertiary alcohols with the diyne moiety in good to high yields with moderate to high enantioselectivities. Furthermore, this
Zinc-mediated enantioselective addition of terminal 1,3-diynes to N-arylimines of trifluoropyruvates
作者:Fa-Guang Zhang、Hai Ma、Yan Zheng、Jun-An Ma
DOI:10.1016/j.tet.2012.05.086
日期:2012.9
A facile and effective enantioselectiveaddition of terminal 1,3-diynes to acyclic α-CF3 ketimine esters has been developed by using zinc/Binol complexes. The reaction works well with a variety of aromatic-, aliphatic- and silyl-substituted diynes, providing the desired products in up to 97% yield and 97% enantiomeric excess.