Cu(II)-Catalyzed [3 + 1 + 1 + 1] Cyclization of 1,3-Diketones and 2-Naphthols Using N,N-Dimethylethanolamine as a Dual Carbon Synthon for the Synthesis of 2H-Chromenes.

Reactions with diverse C1 synthons to realize homologation were well explored. However, homologations occurring twice with one C1 synthon in a reaction were less reported. We disclose herein a Cu(II)-catalyzed novel and efficient synthesis of 2H-chromenes from 2-naphthols, 1,3-diketones, and N,N-dimethylethanolamine (DMEA) as a dual carbon synthon. Various 2H-chromenes with different functional groups are constructed in moderate to good yields. This is the first report that DMEA acts as a dual C1 synthon.

Boosting Alkaline Seawater Oxidation of CoFe-layered Double Hydroxide Nanosheet Array by Cr Doping.

The pursuit of stable and efficient electrocatalysts toward seawater oxidation is of great interest, yet it poses considerable challenges. Herein, the utilization of Cr-doped CoFe-layered double hydroxide nanosheet array is reported on nickel-foam (Cr-CoFe-LDH/NF) as an efficient electrocatalyst for oxygen evolution reaction in alkaline seawater. The Cr-CoFe-LDH/NF catalyst can achieve current densities of 500 and 1000 mA cm -2 with remarkably low overpotentials of only 334 and 369 mV, respectively. Furthermore, it maintains at least 100 h stability when operated at 500 mA cm-2.

Cu(II)-catalyzed domino construction of spironaphthalenones by dearomatization of ß-naphthols and using N,N-dimethylaminoethanol as a C1 synthon.

Herein, a Cu(II)-catalyzed facile construction of synthetically valuable spiro compounds from ß-naphthols in air is reported, in which N,N-dimethylaminoethanol (DMEA) serves as an efficient and unique C1 synthon. This transformation proceeds through an ortho-quinone methide (o-QM) formation/Michael addition/dearomatization sequence, affording various spiro(naphthalenenaphtho)furan-2-ones in moderate to excellent yields.

Application of N,N-Dimethylethanolamine as a One-Carbon Synthon for the Synthesis of Pyrrolo[1,2-a]quinoxalines, Quinazolin-4-ones, and Benzo[4,5]imidazoquinazolines via [5 + 1] Annulation.

The synthesis of N-heterocycles composes a significant part of synthetic chemistry. In this report, a Cu(II)-catalyzed green and efficient synthesis of pyrrolo[1,2-a]quinoxaline, quinazolin-4-one, and benzo[4,5]imidazoquinazoline derivatives was developed, employing N,N-dimethylethanolamine (DMEA) as a C1 synthon. Green oxidant O2 is critical in these transformations, facilitating the formation of a key intermediate─a reactive iminium ion. The method conducted under mild conditions is compatible with a diversity of functional groups, providing an appealing alternative to the previously developed protocols.

Facile construction of C,N-disulfonated 5-amino pyrazoles through an iodine-catalyzed cascade reaction.

A green and facile synthesis of previously unreported C,N-disulfonated 5-amino pyrazoles was established through an iodine-catalyzed cascade reaction of easily accessible sulfonyl hydrazides, ß-ketonitriles, and sodium sulfinates. Diverse C,N-disulfonated 5-amino pyrazoles could be obtained in 38-88% yields. This methodology features green and mild conditions, broad substrate scope, and effortless work-up.