Visible light-induced hydroxyalkylation of 2H-benzothiazoles with alcohols via selectfluor oxidation

A visible-light induced metal-free approach was described for the hydroxyalkylation of 2 Hbenzothiazoles with alcohols by using selectfluor as the oxidant.A variety of 2 H-benzothiazoles and alcohols could be tolerated,providing a mild and simple method for the synthesis of C2-hydroxyalkylated2 H-benzothiazoles in moderate to good yields.Besides,ethers were also compatible in this reaction,leading to corresponding C2 ether-substituted 2 H-benzothiazoles with high regioselectivity.

Fe-catalyzed regioselective Friedel–Crafts hydroxyalkylation of N-substituted glyoxylamide with indoles

An efficient regioselective Friedel-Crafts hydroxyalkylation of N-substituted glyoxylamide with various indoles catalyzed by Lewis acids was developed. The reactions proceeded smoothly at room temperature and the 2-hydroxy-2-（1H-indol-3-yl）-N-substituted acetamide resulted from the reactions catalyzed by FeSO4 were synthesized in excellent yields （up to 93%）. While the bisindole compounds were obtained when FeCl3 was used as a catalyst in excellent yields （up to 92%）. A possible mechanism was proposed.

Ecofriendly Hydroxyalkyl Cellulose Additives for Efficient and Stable MAPbI_(3)-Based Inverted Perovskite Solar Cells

Perovskite solar cells(PSCs)have been demonstrated to be one of the most promising technologies in the field of renewable energy.However,the presence of the defects in the perovskite films greatly limits the efficiency and the stability of the PSCs.The additive engineering is one of the most effective approaches to overcome this problem.Most of the successful additives are extracted from the petroleum-based materials,while the research on the biomass-based additives is still lagging behind.In this paper,two ecofriendly hydroxyalkyl cellulose additives,i.e.,hydroxyethyl cellulose(HEC)and hydroxylpropyl cellulose(HPC),are investigated on the performance of the MAPbl_(3)-based inverted PSCs.Due to the strong interaction between the hydroxyl groups of the cellulose and the divalent cations of the perovskite,these additives enhance the crystal grain orientation and significantly repair the defects of the perovskite films.Working as the additives,these two cellulose derivatives show a strong passivation ability,which significantly reduces the trap density and improves the optoelectronic feature of the PSCs.Compared with the average power conversion efficiency(PCE)of the control device(19.19%),an enhancement of~10%is achieved after the addition of HEC.The optimized device(PCE=21.25%)with a long-term stability(10:80 h,PCE=20.93%)is achieved by the incorporation of the HEC additives into the precursor solution.It is the best performance among the PSCs with the cellulose additives up to now.This research provides a novel choice to develop a cost-effective and renewable additive for the PSCs with high efficiency and excellent long-term stability.

Self-assembly of graphene oxide nanosheets in t-butanol/water medium under gamma-ray radiation

The research on the properties of graphene oxide（GO） in various media has become one of the hottest topics since GO is now the main raw material for graphene-based advanced materials. In this work, the g-ray radiation chemistry effect of GO nanosheets and their self-aggregation behavior in t-butanol/water medium were investigated. The results show that GO nanosheets are reduced and hydroxyalkylated simultaneously by the alcohol free radicals produced by the radiolysis of t-butanol/water solution under g-ray radiation. The radiation-modified GO nanosheets will self-assemble into a self-standing graphene hydrogel when the p H of the solution is lower than 2. A hydroxyl-functionalized free-standing graphene aerogel is further obtained simply by freeze-drying. This work provides not only a general self-assembly mechanism of GO nanosheets in strong acidic alcohol/water media under high energy radiation, but also a facile and economical preparation method for hydroxyalkylated graphene-based aerogel.

THE SYNTHESIS OF 2-FERROCENYL-2-(1-HYDROXYALKYL)-1,3-DITHIANES

There has been now a lot of work done on the 1,3-dithianes chemistry. As a synthetic reagent, 1,3-dithiane has been widely applied to organic syntheses. But no report has been found in literature on the synthesis of derivatives of ferrocene by this versatile method, except that by Reuter et al. In our work a series of new ferrocenyl derivatives, 2-ferrocenyl-2-(1-hydroxyalkyl)-1, 3-dithianes have been synthesized through the following synthetic route: