38788-38-4Relevant articles and documents
(1Z,3Z)-Buta-1,3-dienyl-1-lithium species and substituted tellurophenes by Te/Li exchange on (1Z,3Z)-butyltelluro-1,3-butadienes and (1Z,3Z)-1,4-bis(butyltelluro)-1,3-butadienes
Dabdoub, Miguel J.,Dabdoub, Vania B.,Guerrero Jr., Palimecio G.,Silveira, Claudio C.
, p. 4199 - 4218 (2007/10/03)
(1Z,3Z)-1-Butyltelluro-1,3-butadienes 8, 9 and 12 obtained by the hydrotelluration of but-1-en-3-ynes 1, 2 and 5 were transformed into the corresponding buta-1,3-dienyl-1-lithium by reaction with n-BuLi. 1,3-Butadienes 14, 15, 17-20 were obtained with retention of the double bond geometry by reaction of the butadienyllithium intermediates with electrophiles. The butadienyllithium 13 obtained by the Te/Li exchange reaction in the (1Z,3Z)-1-butyltelluro-4-methoxy-1,3-butadiene 8 was reacted with benzaldehyde to form the corresponding alcohol 15 with total retention of configuration, that undergoes hydrolysis resulting into the (E,E)-5-phenyl-2,3-pentadien-1-al 16. Hydrotelluration of the 1-butyltellurobut-1-en-3-yne 3 permits the synthesis of the (1Z,3Z)-1,4-bis(butyltelluro)-1,3-butadiene 10 which undergoes cyclization, leading to substituted tellurophenes 24, 25, 27-29 via a sequential Csp2-Te and Csp3-Te bonds cleavage on reaction with n-BuLi followed by addition of electrophiles.
Tellurium in organic synthesis. Preparation of Z-vinylic cuprates from Z-vinylic tellurides and their reaction with enones and epoxides
Tucci, Fabio C.,Chieffi, Andre,Comasseto, Joao V.,Marino, Joseph P.
, p. 4975 - 4989 (2007/10/03)
Z-Vinylic tellurides, obtained with 100% stereoselectivity by the hydrotelluration of acetylenes, are easily transformed into Z-vinylic higher order cyanocuprates by reaction with preformed Me2-Cu(CN)Li2, W-Bu2Cu(CN)Lisub
Generation of allyl- and benzyllithiums from the corresponding halides by the aid of lithium-tellurium exchange reactions
Kanda, Takahiro,Kato, Shinzi,Sugino, Takushi,Kambe, Nobuaki,Sonoda, Noboru
, p. 71 - 84 (2007/10/02)
A variety of allyl- and benzyllithiums were prepared by lithium-tellurium exchange reactions of allylic and benzylic tellurides generated in situ from the corresponding halides.The produced organolithiums were trapped successfully with electrophiles such as aldehydes, ketones, and trimethylchlorosilane.Benzyllithiums having an alkyl, alkoxy,fluoro, chloro, or cyano substituent(s) on their aromatic ring were generated efficiently in THF.Benzylic tellurides bearing a bromo or iodo substituent afforded a mixture of products under similar conditions arising from the competing lithium-halogen exchange and/or the displacement of the halogen atom with organolithiums used, but they were converted selectively to benzyllithiums in ether without affecting halogen substituents on the benzene ring.Several allyllithiums including dilithioisobutene were generated from allylic halides in a similar way via allylic tellurides.Wurtz-type coupling was negligible in any reactions examined. Key words: Tellurium; Lithium; Allyl; Benzyl; Halide
Transmetallation Between Vinylic Tellurides and Higher Order Cyanocuprates: In Situ Formation of Vinyl Cuprates
Comasseto, J. V.,Berriel, J. N.
, p. 1681 - 1685 (2007/10/02)
Vinylic tellurides react with higher order dialkylcyanocuprates leading to mixed vinylcyanocuprates with retention of the olefin geometry.The mixed vinylcyanocuprates react with enones giving the 1,4-addition products in good yields.
REACTIONS OF CHALCOGENS WITH ACETYLENES. VI. REACTIONS OF CHALCOGENS WITH PHENYLACETYLENE AND ALKYL HALIDES
Potapov, V. A.,Amosova, S. V.,Kashik, A. S.,Gusarova, N. K.,Trofimov, B. A.
, p. 2057 - 2062 (2007/10/02)
A method was developed for the production of alkyl phenylethynyl selenide with yields of up to 70percent on the basis of an investigation into the reaction of chalcogens with phenylacetylene and alkyl halides in the superbasic potassium hydroxide-hexamethylphosphorotriamide system.
VINYLLITHIUMS FROM BUTYL VINYL TELLURIDES AND BIS-VINYL TELLURIDES
Barros, Simone M.,Comasseto, Joao V.,Berriel, Jorge
, p. 7353 - 7356 (2007/10/02)
Butyl vinyl tellurides and bis-vinyl tellurides furnish vinyllithiums with retention of configuration in good yields upon treatment with n-butyllithium at -78 deg C.
TELLUROPHOSPHONIUM-KATIONEN
Kuhn, Norbert,Schumann, Hans
, p. 199 - 202 (2007/10/02)
Tellurophosphoranes R3P=Te (R = CH3, i-C3H7, n-C4H9, t-C4H9, N(CH3)2) 1 react with CH3I to give the cations + 2.Te(CH3)2 and R3P are formed on treatment of 2 with LiCH3.
DIALKYLTELLURONIUM ALLYLIDE AS A NOVEL REAGENT FOR SYNTHESIS OF Α,Β-UNSATURATED EPOXIDES
Osuka, Atsuhiro,Suzuki, Hitomi
, p. 5109 - 5112 (2007/10/02)
Reaction of dialkyltelluronium allylide with aldehydes gave rise to α,β-unsatirated epoxides with moderate Z-selectivity and in good yields.
