Highly stereoselective method to prepare bis-phenylchalcogen alkenes via addition of chalcogenolate to phenylseleno alkynes
摘要:
The preparation of bis-phenylchalcogen alkenes starting from phenylseleno alkynes is described. The nucleophilic species of selenium, tellurium and sulfur were generated in situ from the reaction of the respective diphenyl dichalcogenide with NaBH4 in PEG-400 as solvent. The chalcogenolate anions were efficiently and selectively added to a variety of phenylselenoalkynes at mild conditions, furnishing the respective (Z)-1,2-bis-phenylchalcogen alkenes in good yields. (C) 2012 Elsevier Ltd. All rights reserved.
A highly chemo-, regio-, and stereoselective method for the synthesis of (Z)-vinylic selenosulfides and (Z)-vinylic tellurosulfides in a one-pot reaction of terminal alkynes, diaryl disulfides, and diaryl diselenides (ditellurides) catalyzed by simple base cesiumhydroxide monohydrate is described. Due to the different activities of the carbon–chalcogen bonds, the target products cleave selectively
Cesium-catalyzed highly regioselective synthesis of (Z)-vinylic selenosulfides via thioselenation of alkynes with unsymmetrical diorganoyl dichalcogenides
A novel one-pot approach for the synthesis of (Z)-vinylic selenosulfides is demonstrated through the thioselenation of a wide range of alkynes with unsymmetrical diorganoyl dichalcogenides (RSSePh) catalyzed by cesium hydroxide monohydrate, avoiding the use of the transition metal catalyst and the previous preparation of chalcogen alkynes. Other outstanding features include mild reaction conditions
Cesium hydroxide-catalyzed hydrothiolation of alkynyl selenides to highly stereo- and regioselectively synthesize (Z)-1-organoseleno-2-arylthio-1-alkenes
In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive (Z)-1-organoseleno-2-arylthio-1-alkene in excellent yields. It could provide a new and expedient way for the preparation of (Z)-1-arylseleno-2-arylthio-1-alkene. (C) 2011 Xin Hua Xu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
Highly stereoselective method to prepare bis-phenylchalcogen alkenes via addition of chalcogenolate to phenylseleno alkynes
作者:Gelson Perin、Elton L. Borges、Diego Alves
DOI:10.1016/j.tetlet.2012.02.028
日期:2012.4
The preparation of bis-phenylchalcogen alkenes starting from phenylseleno alkynes is described. The nucleophilic species of selenium, tellurium and sulfur were generated in situ from the reaction of the respective diphenyl dichalcogenide with NaBH4 in PEG-400 as solvent. The chalcogenolate anions were efficiently and selectively added to a variety of phenylselenoalkynes at mild conditions, furnishing the respective (Z)-1,2-bis-phenylchalcogen alkenes in good yields. (C) 2012 Elsevier Ltd. All rights reserved.