Three-component cyclocondensations. Two methods for the efficient preparation of 5-aminothiazolium salts via the reaction of isocyanides either with dimethylthioformamide and imino chloro sulfides or benzaldimines and aryl chlorothioformates
摘要:
Treatment of imino chloro sulfides with dimethylthioformamide and isocyanides at room temperature provides selectively the 5-amino-4-(dimethylamino)-2-(methylthio)(or phenylthio)thiazolium salts. Similarly, the reactions of p-tolyl chlorothionoformate and phenyl chlorodithioformate with a mixture of benzaldimine and isocyanide afford rapidly the 5-amino-4-phenylthiazolium salts. We suggest that these reactions involve the N-(thiocarbonyl)formamidinium and benzylideniminium chlorides as transient intermediates, which are trapped by isocyanides according to a [1 + 4] cycloaddition process. The structure of the thiazolium salts and some of their reactivities are discussed.
Three-component cyclocondensations. Two methods for the efficient preparation of 5-aminothiazolium salts via the reaction of isocyanides either with dimethylthioformamide and imino chloro sulfides or benzaldimines and aryl chlorothioformates
摘要:
Treatment of imino chloro sulfides with dimethylthioformamide and isocyanides at room temperature provides selectively the 5-amino-4-(dimethylamino)-2-(methylthio)(or phenylthio)thiazolium salts. Similarly, the reactions of p-tolyl chlorothionoformate and phenyl chlorodithioformate with a mixture of benzaldimine and isocyanide afford rapidly the 5-amino-4-phenylthiazolium salts. We suggest that these reactions involve the N-(thiocarbonyl)formamidinium and benzylideniminium chlorides as transient intermediates, which are trapped by isocyanides according to a [1 + 4] cycloaddition process. The structure of the thiazolium salts and some of their reactivities are discussed.
Base-induced conversion of 5-aminothiazolium salts into substituted pyrroles and pyrrolines via 1,3-dipolar cycloadditions with electron-deficient alkynes and alkenes
作者:Fabienne Berrée、Georges Morel
DOI:10.1016/0040-4020(95)00359-g
日期:1995.6
base-catalyzed rearrangements of the primary 1 : 1 cycloadducts, with retention of the elements of isothiocyanate. A similar initial cycloadduct 17 was isolated from N-phenylmaleimide which generally led to the condensed imino thiopyrans 20. Some of the 1,3-dipolar reactional stereoselectivities were deduced from the stereochemistry or distribution of the final products and found to be markedly dependent
Three-component cyclocondensations. Two methods for the efficient preparation of 5-aminothiazolium salts via the reaction of isocyanides either with dimethylthioformamide and imino chloro sulfides or benzaldimines and aryl chlorothioformates
Treatment of imino chloro sulfides with dimethylthioformamide and isocyanides at room temperature provides selectively the 5-amino-4-(dimethylamino)-2-(methylthio)(or phenylthio)thiazolium salts. Similarly, the reactions of p-tolyl chlorothionoformate and phenyl chlorodithioformate with a mixture of benzaldimine and isocyanide afford rapidly the 5-amino-4-phenylthiazolium salts. We suggest that these reactions involve the N-(thiocarbonyl)formamidinium and benzylideniminium chlorides as transient intermediates, which are trapped by isocyanides according to a [1 + 4] cycloaddition process. The structure of the thiazolium salts and some of their reactivities are discussed.