ISSN:
0009-2940
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
A New Preparative Entry to Thiophene Derivatives by Way of Thermal [3 + 2] Cycloaddition Reactions of Mesoionic 1,3-Dithiolones to AlkynesAs cyclic thiocarbonyl ylids the 1,3-dithiolylium-4-olats 1a-jcombine in 2,5-position at 90-130°C with dimethyl acetylenedicarboxylate with formation of non-isolable primary adducts of type 2. The latter fragment with fast evolution of carbon oxisulfide to give the thiophene diesters 3a, b, d, f, h-j in 67-100% yield. The analogous cycloaddition reactions of 1a with propiolic ester, phenylpropiolic ester, acetyl phenylacetylene, benzoyl phenylacetylene and phenylacetylene yield the thiophene derivatives 6-10.
Notes:
Die 1,3-Dithiolylium-4-olate 1a-j nehmen als cyclische Thiocarbonyl-ylide in 2.5-Stellung bei 90-130°C Acetylendicarbonester unter Bildung nicht isolierbarer Primäraddukte vom Typ 2 auf. Diese zerfallen rasch unter Kohlenoxysulfid-Abspaltung in 67-100proz. Ausbeute zu den Thiophen-dicarbonestern 3a, b, d, f, h-j. Die analogen Cycloadditionen von 1a an Propiolester, Phenylpropiolester, Acetylphenylacetylen, Benzolylphenylacetylen bzw. Phenylacetylen ergeben die Thiophen-Derivate 6-10.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19761090236
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