Iodophor-/H2O2-Mediated 2-Sulfonylation of Indoles and N-Methylpyrrole in Aqueous Phase.

A convenient and efficient strategy for the preparation of 2-sulfonylindoles has been achieved through iodophor-/H2O2-mediated 2-sulfonylation of indoles with readily available sulfonyl hydrazides in the aqueous phase. Iodophor is commercially available and serves as the green catalyst and aqueous phase. A series of 2-sulfonylated products from indoles and N-methylpyrrole were synthesized in moderate yields in only 10 min. Control experiments were also conducted to reveal the mechanism of action. This method is environment friendly, easy to operate and suitable for a wide range of substrates.

Reactions of Amidinate-Supported Silylene with Organoboron Dihalides.

The silicon atom in LSiCl or LSiMes (L = PhC(NtBu)2, Mes = 2,4,6-Me3C6H2) inserts into the B-X bond of RBX2 (R = Ph, Mes, N(SiMe3)2; X = Cl, Br), which is followed by the migration of the amidinate ligand and the halide atom. By this way, LB(R)SiCl3 (R = Ph, 2; Mes, 3; N(SiMe3)2, 4) and LB(R)SiX2Mes (R = Ph, X = Cl, 5; R = Mes, X = Cl, 6; R = Mes, X = Br, 7) were obtained. Furthermore, a silylene-borane adduct LClSi → BPhCl2 (1) was obtained as an intermediate in the formation of compound 2. Compounds 2-7 are rare examples of borylhalosilanes.

HAlCl2 and H2AlCl as Precursors for the Preparation of Compounds with Four- and Five-Coordinate Aluminum.

Carbenes are known as donor molecules to form with chloroalane adducts, which enhances their aerobic and thermal stabilities. In contrast, the insertion products (cAACH)AlCl2(cAAC) (1) and (cAACH)AlHCl(THF) (2; THF = tetrahydrofuran) have been formed in the reaction of a cyclic alkyl(amino)carbene (cAAC:) with HAlCl2, and H2AlCl, respectively. PhC(NtBu)2Li as the precursor for the reaction with HAlCl2 in a molar ratio of 2:1 can easily form compound [PhC(NtBu)2]2AlH (3) with five-coordinate aluminum. The new products have been studied by spectroscopic methods and single-crystal X-ray diffraction.

Iodophor-catalyzed sulfenylation of indoles with sulfonyl hydrazides for the synthesis of 3-sulfenylindoles.

An iodophor-catalyzed sulfenylation of indoles using sulfonyl hydrazides as sulfur source to synthesize 3-sulfenylindoles in aqueous phase has been achieved. Notably, iodophor as catalyst and solvent is inexpensive, commercially available and no innocuous to the environment. The method is also easy to operate. Moreover, the synthetic strategy features a wide range of substrates with excellent tolerance to diverse functional groups. A plausible mechanism for the iodophor-mediated 3-sulfenylation of indoles with sulfonyl hydrazides has been proposed. In addition, 3-(phenylthio)-1H-indole was obtained on a multi-gram scale.