Diastereoselective synthesis of α,β-unsaturated systems
摘要:
Functionalized Z-vinylic tellurides were used in substitution reactions with lower order cyanocuprates leading to alpha, beta-unsaturated ketones and esters in good yields. In the case of acyclic tellurides, the product was obtained in high diastereoselectivity. The control of the stereoselectivity was achieved by simple change of the reaction temperature. (C) 2005 Elsevier Ltd. All rights reserved.
Novel cross-coupling reactions between organotellurides and Grignard reagents employing a MnCl2/CuI catalytic system
作者:Marcio S. Silva、Renan S. Ferrarini、Bruno A. Sousa、Fabiano T. Toledo、João V. Comasseto、Rogério A. Gariani
DOI:10.1016/j.tetlet.2012.04.134
日期:2012.7
We present a general protocol for the cross-coupling reaction of Grignardreagents and organic tellurides. Aryl Grignardreagents react stereospecifically with vinyl tellurides in the presence of a catalytic amount of manganese (II) chloride and copper (I) iodide to produce good yields of the corresponding cross-coupling products.
The coupling of butylvinyltellurides with organometallic reagents catalysed by nickel complexes
作者:Cristiano Raminelli、João Gargalaka、Cláudio C. Silveira、João V. Comasseto
DOI:10.1016/j.tet.2007.06.057
日期:2007.9
Vinylic tellurides couple efficiently with sp, sp(2) and sp(3) hybridised organometallic compounds (Li, MgX and Zn species) in the presence of dichloro-bis( triphenylphosphine) nickel(II) as catalyst. (c) 2007 Elsevier Ltd. All rights reserved.
Diastereoselective synthesis of α,β-unsaturated systems
作者:Priscila Castelani、João V. Comasseto
DOI:10.1016/j.tet.2005.01.025
日期:2005.2
Functionalized Z-vinylic tellurides were used in substitution reactions with lower order cyanocuprates leading to alpha, beta-unsaturated ketones and esters in good yields. In the case of acyclic tellurides, the product was obtained in high diastereoselectivity. The control of the stereoselectivity was achieved by simple change of the reaction temperature. (C) 2005 Elsevier Ltd. All rights reserved.
Chemoselective reduction of β-butyltellanyl α,β-unsaturated carbonyl compounds to allylic alcohols
作者:Alcindo A. Dos Santos、Priscila Castelani、Bruno K. Bassora、José C. Fogo Junior、Carlos E. Costa、João V. Comasseto
DOI:10.1016/j.tet.2005.06.090
日期:2005.9
(Z)-β-Butyltellanyl α,β-unsaturated carbonyl compounds were stereoselectively produced by hydrotelluration of alkynones or by an addition/elimination sequence from enol tosylates. The β-butyltellanyl-enones were chemoselectively reduced with NaBH4/MeOH, NaBH4·CeCl3·7H2O/MeOH and DIBAL-H systems to the corresponding allylic alcohols with retention of the Z stereochemistry.