Isothiocyanates, adducts with thiazolium

Isocyanine, hydride ion transfer in, 43 Isoindoles, from 5-hydroxy-THlSs, 9 Isothiocyanates, adducts with thiazolium salts, 35... 

Nucleophilic carbenoids (also called ylides by some authors) react with heterocumulenes, such as isocyanates and isothiocyanates, to yield hy-dantoins, 2-thiohydantoins, and 2,4-dithiohydantoins via dipolar intermediates. Thus dimethoxycarbene adds to aryl isocyanates and isothiocyanates to form 5,5-dimethoxyhydantoins and dithiohydantoins.107 Thiazolium ylides (61) (resulting from thiazolium salts and NEt3 in DMF) give dipolar 1 1 adducts (62) or l 2-cycloadducts (63) with isocyanates or isothiocyanates.108-110 Other substrates are imidazolidine111 or 2-imidazoline derivatives.112... 

Thiazolium ylides 18 also react with isothiocyanates to give the fused spiro ring systems 20 or linear ionic 1 1 adducts 19. Electron withdrawing substituents in aryl isothiocyanates support the formation of the ionic 1 1 adducts, while electron donating substituents favor the formation of the [1+2+2] cycloadducts . 

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