Reaction of tellurium tetrachloride with acetylene

Abstract

No data on the reaction of tellurium tetrachloride with acetylene are available, however, it is known that tellurium tetrachloride reacts with substituted acetyl enes. 1-7 Reactions of tellurium tetrachloride with phenyl acetylene, diphenylacetylene, and arylalkynes are known to proceed as the syn addition resulting in Z configured products exclusively. 1-6 This was confirmed by X ray dif fraction data. 4 Reactions of organyltellurium trichlorides with alkynes also proceed as the syn addition resulting in Z organyl(2 chlorovinyl)tellurium dichlorides. 8,9 The mechanism 8,9 including four membered cyclic transition state was suggested for the explanation of the stereospe cific syn addition of tellurium tetrachloride and organyl tellurium trichlorides to the triple bond. Reaction of tellurium tetrachloride with propargyl alcohol and its derivatives is a special case: substitution of the hydroxyl group for the chlorine atom at the tellurium atom result ing in formation of cyclic products occurs along with the addition to the triple bond. 5 We carried out the addition of tellurium tetrachloride to acetylene for the first time (Scheme 1). It was estab lished that the reaction affords hitherto unknown E,E bis (2 chlorovinyl)tellurium dichloride (1) in 62% yield. The process proceeds in chloroform at 20-40 °С under acetyl ene pressure of ~12 atm. Scheme 1Dichloride 1 is a promising intermediate for the syn thesis of organotellurium products. This is a colorless crystalline substance, its structure was established by the 1 H and 13 C NMR spectroscopy and mass spectrometry and confirmed by data from elemental analysis. The spinspin coupling constant for trans vinyl protons of product 1 (J = 13.6 Hz) is typical of E 2 chlorovinyl chalco genides. 10,11 It is known 11 that the spin-spin coupling constants for cis vinyl protons of Z 2 chlorovinyl chalco genides are ~6.5 Hz. The mass spectrum of product 1 contains a peak of the ion with m/z 287, which corre sponds to the molecular ion of the product lacking one chlorine atom. It was established 12 that the mass spectra of diorganyltellurium dichlorides do not contain peaks of molecular ions, but there are the ions [M -Cl] + .Thus, the reaction of tellurium tetrachloride with acetylene (in contrast to other alkynes 1-7 ) proceeds as the anti addition and leads to the E configured product. The reaction is the first example of the stereospecific anti addition of tellurium tetrachloride to the triple bond of acetylenic hydrocarbons. One can suppose that, in the case of acetylene, the anti addition via three membered intermediates 2 and 3 (see Scheme 2) becomes more favorable than the syn addition.The formation of such a three membered intermedi ates is proposed in the reactions of organylsulfenyl and organylselenenyl chlorides with alkynes proceeding as the electrophilic anti addition. 13

Highly efficient regioselective synthesis of organotellurium compounds based on the reactions of tellurium tetrachloride with 1-alkenes

“…[10][11][12][13][14][15] We are making a systematic study of the reactions of tellurium tetrahalides with unsaturated compounds. [16][17][18][19][20][21][22][23][24][25] Recently we have found that methoxytelluration can be accomplished by the reaction of tellurium tetrabromide with 1-hexene in methanol. 17 The reaction proceeded with high regioselectivity to afford Markovnikov's products, tribromo-(2-methoxyhexyl)-λ 4 -tellane.…”

Tellurocyclisation of Condensed N-Alkenyl Derivative 4-Oxopyrymidine-2-Tion

“…Наше дослідження присвячено синтезу нових функціоналізованих ненасичених конденсованих похідних хіназолін-4-ону та дослідження регіохімії процесу електрофільної гетероциклізації під дією телур тетрахлориду. Вибір такого електрофільного реагенту зумовлено тим, що в останні роки дедалі активніше розвивається органічний синтез халькогеновмісних сполук, зокрема, телуровмісних [7][8][9][10][11], які проявляють широкий спектр біологічної активності [12][13][14]. Тому синтез телуровмісних сполук на основі хіназолін-4-ону є важливим завданням з огляду на їх перспективні біологічні властивості.…”

Synthesis of Z,Z-Bis(2-chlorovinyl)ditelluride

“…The stereoselective synthesis of ditellurides containing 2-halovinyl group is an important synthetic problem in the chemistry of organotellurium compounds. As a rule, the preparation of these compounds is based on the addition of tellurium tetrachloride to alkynes [3][4][5][6][7][8].…”

“…Earlier, we have first performed the reaction of tellurium tetrachloride with acetylene, which occurs stereoselectively as the anti-addition and results depending on the conditions of the reaction in Е-(2chlorovinyl)tellurium trichloride or Е,Е-bis(2-chlorovinyl)telluriumdichloride [3][4][5]. The reduction of Е-(2chlorovinyl)tellurium trichloride by sodium pyrosulfite affords Е,Е-bis(2-chlorovinyl)ditelluride [3][4][5], which was used for introduction of the Е-2-chlorovinyltellurium group in organic compounds.…”

“…The reduction of Е-(2chlorovinyl)tellurium trichloride by sodium pyrosulfite affords Е,Е-bis(2-chlorovinyl)ditelluride [3][4][5], which was used for introduction of the Е-2-chlorovinyltellurium group in organic compounds.…”