Thioketones azomethines

Similarly small rate factors were obtained for 1,3-dipolar cycloadditions between diphenyl diazomethane and dimethyl fumarate [131], 2,4,6-trimethylbenzenecarbonitrile oxide and tetracyanoethene or acrylonitrile [811], phenyl azide and enamines [133], diazomethane and aromatic anils [134], azomethine imines and dimethyl acetylenedi-carboxylate [134a], diazo dimethyl malonate and diethylaminopropyne [544] or N-(l-cyclohexenyl)pyrrolidine [545], and A-methyl-C-phenylnitrone and thioketones [812]. Huisgen has written comprehensive reviews on solvent polarity and rates of 1,3-dipolar cycloaddition reactions [541, 542]. The observed small solvent effects can be easily explained by the fact that the concerted, but non-synchronous, bond formation in the activated complex may lead to the destruction or creation of partial charges, connected... 

Azomethines have also been obtained in the reaction of azides with thioketones. Thiobenzephenone and phenyl azide thus yielded ben-zophenone anil (72), probably via the cyclic intermediate 71 . ... 

The 1,3-dipolar cycloaddition reaction of azomethine ylides with thioketones has been used to prepare 1,3-thiazoIidines. The metallated azomethine ylides 67 were generated in situ by treating a-amino acid ester imines 66 with lithium bromide and DBU. The ylides were then treated with highly reactive thioketones such as thiobenzophenone or fluorene-9-thione, to afford 1,3-thiazolidine derivatives 68 (main isomer) and 69 (minor isomer) in good yield and in diastereoisomeric ratios of between 2 1 and 4 1 <01H(55)691>. 

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