Preparation and Interconversion of Phenylselenenylated and Alkylselenenylated Aromatic Compounds
摘要:
Phenylselenenyl and alkylselenenyl sulfates were found to efficiently and mildly introduce one or several phenylselenenyl or alkylselenenyl groups into activated aromatic or heteroaromatic compounds. When treated with methylselenenyl sulfate, veratrole and 2,2',3,3'-tetramethoxybiphenyl afforded 2,3,7,8-tetramethoxyselenanthrene and 2,3,7,8-tetramethoxy-dibenzoselenophene, respectively, via oxidative demethylation at selenium/cyclization. Phenyl-selenenylated thiophenes were selectively hydrodeselenenated at the 2- and/or 5-positions by treatment with the appropriate amount of n-butyllithium at -78 degrees C followed by hydrolysis.
A general procedure for the synthesis of methylthio-, methylseleno- and methyltelluro-substituted aromatic compounds
作者:Lars Engman、Jonas S.E. Hellberg
DOI:10.1016/0022-328x(85)80366-1
日期:1985.12
A one-pot procedure is described which allows the facile introduction of one or two methylchalcogeno groups into a variety of monobromo or dibromo aromatics. The bromo compounds were converted to their corresponding lithio derivatives by treatment with t-butyllithium in tetrahydrofuran at −78°C, and these derivatives were then treated, at ambient temperature with elemental sulfur, selenium, or tellurium