Hydrochalcogenation of activated olefines. Synthesis of functionalized dialkylchalcogenides
摘要:
Alkanethiols, selenols and tellurols are generated in situ by reaction of elemental sulfur, selenium and tellurium with commercial alkyllithiums, followed by reaction with deoxygenated water. The alkanechalcogenols react in situ with activated ole. ns in a Michael- type addition reaction. (c) 2008 Elsevier B. V. All rights reserved.
β-Functionalized selenides and tellurides by hydrochalcogenation of olefins containing electron-withdrawing groups
作者:Fabiano K. Zinn、Vinı́cius E. Righi、Silas C. Luque、Henrique B. Formiga、João V. Comasseto
DOI:10.1016/s0040-4039(02)00095-3
日期:2002.2
Olerins conjugated to electron-withdrawing groups (e.g. CHO, RCO, CO2R, CN) react rapidly with alkylselenols and tellurols generated in situ to give the corresponding beta-chalcogeno aldehydes, ketones, esters and nitriles. beta-Telluroketones are transformed into beta-telluroketals, which are beta-lithiocarbonyl synthons. (C) 2002 Elsevier Science Ltd. All rights reserved.
Functionalized organozincates and organocuprates derived from γ-hydroxytellurides in the preparation of 1,4-hydroxyketones
作者:Jefferson L. Princival、Alcindo A. Dos Santos、João V. Comasseto
DOI:10.1016/j.tetlet.2009.08.097
日期:2009.11
A C-O-dianionic zincate was generated by a Te/Li exchange reaction of an alkyltelluride, followed by Li/Zn transmetallation and reaction with methyllithium. The reaction between the enantiomerically pure (99% ee) (R)-dianionic zincate and benzoyl chloride led to 3-hydroxy-1-phenyl pentanone with total retention of the carbon configuration (99% ee). Similar results were obtained using the corresponding Lipshutz cyanocuprates. (C) 2009 Elsevier Ltd. All rights reserved.