Thioketones and thioaldehydes, fluorinated
1,3-Dipoles, bis-stannylated-, bis-silylated-
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Partially and Perfluorinated Thioketones and Thioaldehydes: Chemical Storage, In Situ Generation and Surprising Reactivity towards Bis(trimethylstannyl)-diazomethane (BTSD) and C,N-Bis(triisopropylsilyl)nitrilimine (NI)The hetero-Diels-Alder anthracene adducts 1a-d are synthesized in a one-pot reaction from the corresponding partially and perfluorinated carbonyl compounds in good yields. By their thermolysis in solution in presence of BTSD or NI the 1,3-dipolar 1:1 cycloadducts 12a, d, 14a, b, d are obtained without any detectable by-products. The method can be of wide applicability predominantly for any aliphatic CS-unsaturated species, which are not accessible in substance due to tendency towards polymerisation, but can be stabilized as anthracene adducts. Other 1,3-dipolar cycloaddition products of BTSD and NI are obtained from reaction with iso-lable hexafluorothioacetone (6f) or bis(trifluoromethyl)sulfine (7f). Comparative studies were carried out with hexafluoroacetone (8), 12a, d, e, 13 are consecutive products from a 1,2-metallotropic migration of the primary addition compounds. 14a, b, d, 15, 16 are useful thiadiazolines with respect to the synthesis of active substances because of their seldom found peripheral functionality. Desilylation was achieved by fluoride support. An X-ray structure determination of 12a and 14d was carried out. In addition trifluoromethylsulfine (7c) was trapped at low temperatures. It dimerizes at ambient temperature to unsymmetrical 1,2-dithietane 11.
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