Stereospecific chlorotelluration of terminal acetylenes

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• 作者：Ashok K.S. Chauhan^a ; ^{akschauhan2003@yahoo.co.in} ; ^{akschauhan@hotmail.com} ; Swami N. Bharti^a ; ^{goswamiswaminath@yahoo.com} ; Ramesh C. Srivastava^a ; ^{rameshlko@yahoo.co.nz} ; Ray J. Butcher^b ; ^{rbutcher99@yahoo.com} ; Andrew Duthie^c ; ^{aduthie@deakin.edu.au}
• 关键词：Vinyltellurium ; Chlorotelluration ; Secondary bonding interaction ; Steric role
• 刊名：Journal of Organometallic Chemistry
• 出版年：2012
• 期刊代码：64_0022328x
• 类别：ch
• 出版时间：15 June, 2012
• 卷：708-709
• 期：Complete
• 页码：75-81
• 文件大小：562 K

摘要

Chlorotelluration of terminal acetylenes, RCHCH (R聽=聽Ph, 1; 4-MeC₆H₄, 2; t-Bu, 3) with aryltellurium trichlorides and TeCl₄ in refluxing toluene affords (2-chloro-2-organylvinyl)tellurium(IV) dichlorides, Ar[R(Cl)CCH]TeCl₂ (Ar聽=聽1-C₁₀H₇, 1Aa-3Aa; 2,4,6-Me₃C₆H₂, 1Ba-3Ba; 4-MeOC₆H₄, 1Ca) and [t-Bu(Cl)CCH]₂TeCl₂, 3a respectively. These Te(IV) derivatives on reduction with Na₂S₂O₅ give the corresponding vinyltellurides as oils, except (2,4,6-Me₃C₆H₂)[Ph(Cl)CCH]Te (1B) which is a crystalline solid. The dibromides (1Ab-3Ab, 1Bb-3Bb, 3b) and diiodides (1Ac-3Ac, 1Bc-3Bc, 1Cc) were obtained by the oxidative addition of dihalogens to the tellurides. The stereochemistry of the products has been established with the help of X-ray diffraction studies of 1Aa, 1Ba, 1Bc, 1Cc, 3Aa, 3a and 1B. Intramolecular Te鈰疌l attractive interactions appear to favor the (Z) conformation adopted by the 2-chloro-2-organylvinyltellurium group irrespective of the steric demand of the aryl ligand of the Te(IV) electrophile and the terminal acetylene substituent. The intermolecular Te鈰疿 secondary bonding interactions give rise to dimeric units in the lattices of 1-naphthyl- and anisyltellurium(IV) derivatives, but are absent among the mesityl analogues, consistent with the larger steric requirement of the latter ligand.