Lewis acid catalyzed Markovnikov hydrobromination and hydrochlorination of alkynes using TMSX (X = Br, Cl).

Markovnikov hydrobromination and hydrochlorination of alkynes were achieved using TMSX (X = Br, Cl) instead of corrosive HX (X = Br, Cl) as the bromination and chlorination reagents. Mn(OAc)2·4H2O was used as the hydrobromination catalyst for electron-neutral/rich alkynes. For the hydrobromination of electron-deficient alkynes and hydrochlorination of alkynes, Zn(OAc)2·2H2O was employed as the catalyst. Mechanistic studies suggested that the in situ formed TMS-substituted alkyne might be a reactive intermediate and the proton of the terminal alkyne should be a hydrogen source for the hydrohalogenation reaction.

Ru-Catalyzed Synthesis of α,ß-Unsaturated Acylsilanes and Its Applications in C-N Bond Formation.

α,ß-Unsaturated acylsilanes have multifunctional sites and can be used in many transformations. However, the existing methods for preparing them generally suffer from problems, such as low atom and step economy, a narrow substrate scope, etc. Herein, an efficient and general method for accessing α,ß-unsaturated acylsilanes through Ru-catalyzed cross-metathesis has been developed. This method is applied to various acylsilanes, especially those ß-alkyl-α,ß-unsaturated acylsilanes, which are difficult to prepare with the classical methods. In addition, the utilities of the products have been demonstrated through two distinct C-N bond formation reactions.

Z-Scheme In2 S3 /NU-1000 Heterojunction for Boosting Photo-Oxidation of Sulfide into Sulfoxide under Ambient Conditions.

Photocatalytic oxidation of sulfide into sulfoxide has attracted extensive attention as an environmentally friendly strategy for chemical transformations or toxic chemicals degradation. Herein, we construct a series of In2 S3 /NU-1000 heterojunction photocatalysts, which can efficiently catalyze the oxidation of sulfides to form sulfoxides as the sole product under LED lamp (full-spectrum) illumination in air at room temperature. Especially, the sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES), can also be photocatalytically oxidized with In2 S3 /NU-1000 to afford nontoxic 2-chloroethyl ethyl sulfoxide (CEESO) selectively and effectively. In contrast, individual NU-1000 and In2 S3 show very low catalytic activity on this reaction. The significantly improved photocatalytic activity is ascribed to the constructing of an efficient Z-scheme photocatalysts In2 S3 /NU-1000, which exhibits the enhancement of light harvesting, the promotion of photogenerated electron-hole separation, and the retention of high porosity of the parent MOF. Moreover, mechanism studies in photocatalytic oxidation reveal that the superoxide radical (. O2 - ) and singlet oxygen (1 O2 ) are the main oxidative species in the oxidation system. This work exploits the opportunities for the construction of porous Z-scheme photocatalysts based on the photoactive MOFs materials and inorganic semiconductors for promoting catalytic organic transformations. More importantly, it provides a route to the rational design of efficient photocatalysts for the detoxification of mustard gas.