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• N -sulfonyl-1,2,3-triazole was used as a 1-aza-[4C] synthon. • Excellent chemoselectivity was observed. • Fused pyrimidine and seven-membered 1 H -1,4-diazepine were synthesized effectively. A new synthetic application of N -sulfonyl-1,2,3-triazoles acting as a 1-aza-[4C] synthon via the 1,2-shift reaction of an α-imine rhodium carbene was developed for the synthesis of fused pyrimidine derivatives. The high reactivity of the strained three-membered 2 H -azirine ring facilitated the unusual cyclization of electron-deficient dienes with electron-deficient dienophiles. The compatibility was good with common functionalities tolerated. Excellent chemoselectivity was observed, and no reactions occurred between the rhodium carbene and 2 H -azirine. The products could be converted into seven-membered multi-functionalized 1 H -1,4-diazepine derivatives, illustrating the potential application of the protocol in medium-sized N -heterocycle synthesis. [ABSTRACT FROM AUTHOR]

[Display omitted] Isothiocyanates were synthesized by reactions between primary amines and CS 2 in the presence of 4-dimethylaminopyridine as a catalyst and tert -butyl hydroperoxide as an oxidant. Various aryl, benzyl, alkyl, and hydroxyl amines were transformed into the corresponding isothiocyanates in 41–82% yields. [ABSTRACT FROM AUTHOR]

We report a rhodium-catalyzed intramolecular [4 + 3] cycloaddition of 1-sulfonyl-1,2,3-triazoles that enables the efficient synthesis of cyclobutane-fused dihydroazepines in moderate to good yields. Meanwhile, three stereo centers were constructed, and one single diastereomer was obtained in each case. The stereoselectivity control was also discussed. [ABSTRACT FROM AUTHOR]

The first formal intramolecular 1,3-insertion into O Si bond of rhodium(II) azavinyl carbene have been developed, and valuable phthalan derivatives could be synthesized efficiently. In addition, various functional groups could be introduced to the product conveniently in the assistant of TBAF. [Display omitted] The first formal intramolecular 1,3-insertion into O Si bond of rhodium(II) azavinyl carbene have been developed, and valuable phthalan derivatives could be synthesized efficiently. In addition, various functional groups could be introduced to the product conveniently in the assistant of TBAF. [ABSTRACT FROM AUTHOR]