24898-17-7Relevant articles and documents
Phosphine-Free Manganese Catalyst Enables Selective Transfer Hydrogenation of Nitriles to Primary and Secondary Amines Using Ammonia-Borane
Sarkar, Koushik,Das, Kuhali,Kundu, Abhishek,Adhikari, Debashis,Maji, Biplab
, p. 2786 - 2794 (2021/03/03)
Herein we report the synthesis of primary and secondary amines by nitrile hydrogenation, employing a borrowing hydrogenation strategy. A class of phosphine-free manganese(I) complexes bearing sulfur side arms catalyzed the reaction under mild reaction conditions, where ammonia-borane is used as the source of hydrogen. The synthetic protocol is chemodivergent, as the final product is either primary or secondary amine, which can be controlled by changing the catalyst structure and the polarity of the reaction medium. The significant advantage of this method is that the protocol operates without externally added base or other additives as well as obviates the use of high-pressure dihydrogen gas required for other nitrile hydrogenation reactions. Utilizing this method, a wide variety of primary and symmetric and asymmetric secondary amines were synthesized in high yields. A mechanistic study involving kinetic experiments and high-level DFT computations revealed that both outer-sphere dehydrogenation and inner-sphere hydrogenation were predominantly operative in the catalytic cycle.
Surface modification boosts exciton extraction in confined layered structure for selective oxidation reaction
Jin, Sen,Wang, Hui,Li, Lei,Luo, Xiao,Sun, Xianshun,Zuo, Ming,Tian, Jie,Zhang, Xiaodong,Xie, Yi
, p. 1964 - 1969 (2021/10/25)
Extracting photogenerated species from bulk to surface is an essential process for gaining efficient semiconductor-based photocatalysis. However, compared with charged photogenerated carriers, neutral exciton exhibits negligible response to electric field. Accordingly, traditional strategies involving band-alignment construction for boosting directional transfer of charge carriers are impracticable for extracting bulk excitons. To this issue, we here propose that the extraction of bulk exciton could be effectively implemented by surface modification. By taking confined layered bismuth oxycarbonate (Bi2O2CO3) as an example, we highlight that the incorporation of iodine atoms on the surface could modify the micro-region electronic structure and hence lead to reduced energy of surface excitonic states. Benefiting from the energy gradient between bulk and surface excitonic states, iodine-modified Bi2O2CO3 possesses high-efficiency bulk exciton extraction, and hence exhibits promoted performance in triggering 1O2-mediated selective oxidation reaction. This work presents the positive role of surface modification in regulating excitonic processes of semiconductor-based photocatalysts. [Figure not available: see fulltext.].
A highly active worm-like PtMo nanowire for the selective synthesis of dibenzylamines
Lu, Shuanglong,Xu, Pengyao,Cao, Xueqin,Gu, Hongwei
, p. 8755 - 8760 (2018/03/08)
Worm-like nanowires are among the most active nanomaterials. In this study, we report the synthesis of dibenzylamine (DBA) motifs from reductive amination of either aldehydes or nitriles catalyzed by entirely new worm-like PtMo nanowires (PtMo WNWs). Under the assistance of H2 gas, PtMo WNWs can be prepared in a facile manner, following which, their structure and composition are characterized by TEM, XRD, XPS, etc. Upon careful optimization of reaction parameters, the as-prepared PtMo WNWs work effectively in the activation of dihydrogen molecules, and both aldehydes and nitriles can be used as starting materials to fabricate DBAs under mild and green conditions. The reaction kinetics has been investigated, which reveals that the PtMo WNWs show superior activity in the conversion of imines into amines. This study provides a practical advancement in the preparation of amines. Moreover, the protocol reported herein is feasible for the synthesis of worm-like nanostructures with designed composition for various catalytic applications.
