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.
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.
