Synthesis of indenothiophenone derivatives by cycloaromatization of non-conjugated thienyl tetraynes
摘要:
Non-conjugated thienyl tetrayne derivatives 1-3 are prepared as novel building block for the construction of indenothiophenone derivatives. Oxidation of 1-3, followed by cycloaromatization of the corresponding ketone derivatives 13-15 proceeds smoothly to afford indenothiophenone derivatives 16-21 in good yields. (C) 2005 Elsevier Ltd. All rights reserved.
Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 4. Stepwise construction of terminal 1, 3-diynes, conjugated diacetylenic esters and a triacetylenic ester
摘要:
Thirteen examples of stabilised alkynoyl ylides 6 have been prepared and are found, upon flash vacuum pyrolysis (FVP) at 500 degrees C, to undergo extrusion of Ph(3)PO to give the diacetylenic esters 7 in moderate yield. At 750 degrees C the same ylides afforded terminal 1.3-diynes 8 although often in poor yield. For R = 2-MeSC(6)H(4) both 7 and 8 undergo secondary loss of Me(.) and cyclisation to give 2-alkynylbenzothiophene derivatives 9 and 10 in low yield. The first example of an alkadiynoyl ylide 11 has been prepared and is converted by FVP at 500 degrees C into the triacetylenic ester 12.
Highly enantioselective copper(<scp>i</scp>)-catalyzed conjugate addition of 1,3-diynes to α,β-unsaturated trifluoromethyl ketones
作者:Amparo Sanz-Marco、Gonzalo Blay、M. Carmen Muñoz、José R. Pedro
DOI:10.1039/c5cc01676b
日期:——
The conjugate diynylation of [small alpha],[small beta]-unsaturated trifluoromethyl ketones is carried out in the presence of a low catalytic load (2.5 mol %) of a copper(I)-MeOBIPHEP complex, triethylamine and a terminal 1,3-diyne....
Transition-Metal-Free Synthesis of Borylated Thiophenes via Formal Thioboration
作者:Hassen Bel Abed、Suzanne A. Blum
DOI:10.1021/acs.orglett.8b02727
日期:2018.11.2
exclusively 3-borylated thiophene derivatives is reported. The commercially available B-chlorocatecholborane reagent (ClBcat) acts as a carbophilic Lewis acid to activate the alkyne in readily synthesized (Z)-organylthioenyne substrates. This boron-induced activation initiates the formal thioboration and subsequent sulfur dealkylation, leading to the formation of 3-borylated thiophenes in good yields. The
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 Conjugate Alkynylation of α,β-Unsaturated 1,1,1-Trifluoromethyl Ketones with Terminal Alkynes
作者:Amparo Sanz-Marco、Gonzalo Blay、M. Carmen Muñoz、José R. Pedro
DOI:10.1002/chem.201601303
日期:2016.7.11
trifluoromethyl ketones in the presence of a low catalytic load of a CuI‐MeOBIPHEP complex (2.5 mol %) and triethylamine (10 mol %) to give the corresponding trifluoromethyl ketones bearing a propargylic stereogenic center at the β position with good yields and excellent enantiomeric excesses in most of the cases. No 1,2‐addition products were formed under the reaction conditions. The procedure showed broad
Rhodium‐Catalyzed Direct Enantioselective Alkynylation of Trifluoropyruvates with Terminal 1,3‐Diynes
作者:Hui Jiang、Chun‐Yang Zhang、Jin‐Kui Liu、Mao‐Ping Song、Jun‐Fang Gong
DOI:10.1002/adsc.202300993
日期:2023.11.21
A direct catalytic enantioselectivealkynylation reaction of trifluoropyruvates with terminal 1,3-diynes was achieved by using C2-symmetric NCN pincer rhodium (III) complexes with bis(imidazolinyl)phenyl ligands. This protocol is effective for enantioselective synthesis of optically active trifluoromethylated tertiary alcohols with the diyne moiety. A variety of electronically and structurally diverse