The Formation Of C-X(X=N,S) Bond Via Oxidative Coupling Reaction

Oxidative coupling reaction, as a burgeoning synthetic methodology, has been widely utilized in organic synthesis, such as the construction of C-C, C-N, C-S bonds. This paper concentrates on the formation of C-N and C-S bonds via oxidative coupling reaction, and includes five parts as followed.(1) A copper-mediated oxidative N–cyanation reactionCopper-promoted N-cyanation of aliphatic sec-amine by Cu CN is achieved via oxidative coupling. This procedure employs O2 as a clean oxidant. Notably, sulfoximines and 1,1,3,3-tetramethylguanidine also worked well in this procedure. Moreoner, it represents a key progress in the C–N bond formation reaction as well as in cyanation reaction.(2) Copper-catalyzed cyanation of disulfides by azobisisobutyronitrile leading to thiocyanatesThe copper-catalyzed cyanation of disulfides by azobisisobutyronitrile(AIBN) was developed, leading to thiocyanates in moderate to good yields. This procedure tolerates a series of functional groups, such as chloro, nitro, methyl and methoxycarbonyl in the phenyl ring of disulfides. Notably, it enables the use of two Ar S units in(Ar S)2. Cu I was found to be essential for the in situ formation of cyanide anions.(3) Copper-catalyzed N cyanation of sulfoximines by AIBNThe direct copper-catalyzed N-cyanation of sulfoximines was achieved by using AIBN as a safe cyanide source. It represents a simple and environmentally benign procedure for the construction of the N-CN bond. Furthermore, some sec-amines can also be tolerated well under this procedure.(4) Silver-mediated N-trifluoromethylation of sulfoximinesAn unprecedented approach to N-trifluoromethylations of electron-rich nucleophilic sites following a radical pathway is reported. Accordingly, various sulfoximines have been N-trifluoromethylated, providing previously unreported products with satisfying functionality tolerance in moderate to good yields. With a C-N bond length at the N-CF3 moiety of 1.341 ?, the respective linkage is shorter than a traditional C-N single bond and comparable with that of a C-N double bond.(5) Copper-catalyzed oxidative C(sp3)–H/N–H coupling of sulfoximines and amides with simple alkanes via a radical processA copper-catalyzed oxidative C(sp3)–H/N–H coupling of sulfoximines with simple alkanes was developed. This protocol involved C(sp3)–N bond formation via a radical pathway and tolerated a series of functional groups, such as chloro, methyl and aryl, on the phenyl rings. Apart from sulfoximines, amides, saccharin and aniline also worked well to give the corresponding N-alkylated products.