Construction of Optically Active 2H‐ and 3H‐Pyrroles by Cyclization and Chirality Maintaining 1,5‐Ester Shift Reactions

Abstract

Construction of enantioenriched 2H‐ and 3H‐pyrroles are achieved in current work by using readily available α‐isocyanoacetates and alkynyl ketones as precursors. To realize the asymmetric synthesis of 2H‐pyrroles, a proper in situ generated magnesium catalytic method was developed. On the other hand, the discovery of an aluminium mediated chirality maintaining 1,5‐ester shift reaction promoted the successful synthesis of enantioenriched 3H‐pyrroles.magnified image

Subnano‐Sized Pt–Au Alloyed Clusters as Enhanced Cocatalyst for Photocatalytic Hydrogen Evolution

“…The binding energy of 283.5 eV in C 1s spectrum was set as internal reference. The XPS Pt 4f spectrum in Figure a can be fitted into two peaks for Pt 4f 7/2 at 69.6 eV and Pt 4f 5/2 at 73.0 eV . The metallic Pt can be main species, suggesting the entirely reduction of Pt 4+ ions to metallic Pt atoms in the chemical reduction approach.…”

“…This phenomenon can be owed to the different work functions between Pt and Au, and the electrons can easily flow from Au atoms to Pt atoms, leading to an increase of the binding energy of Au . The electron transfer can increase the electron density on the Pt surface, and this should optimize the Pt‐H* coordination and thus the H* adsorption on the Pt surface would be more suitable in Pt–Au/T photocatalyst …”

Dual Cocatalysts in TiO2 Photocatalysis

“…Owing to the fact that the interface is the location where the charge carriers separate, transfer and recombine, controlling the interfacial structures to regulate the type and number of contact interfaces is imperative to improve the efficiency of charge transfer and separation. Accordingly, the integration structure of cocatalysts can be classified into three major types: random deposition, facet‐dependent selective deposition and core–shell structure ( Figure ).…”

Direct Observation of Dynamic Bond Evolution in Single‐Atom Pt/C3N4 Catalysts

“…Intrinsically, only a small portion of Pt atoms on the surface of these metallic Pt particles were involved in photocatalytic reactions, thus resulting in relatively low utilization efficiency of the noble metal. It is therefore imperative to increase the utilization efficiency of Pt atoms while maintaining or improving their catalytic activities …”