Crystal phase-selective synthesis of intermetallic palladium borides and phase-regulated (electro)catalytic properties

Three crystal phases of Pd-B intermetallics, including Pd6B, Pd5B2 and Pd2B, are synthesized, and their phase-dependent catalytic activities toward electrochemical water splitting and Suzuki coupling reaction are studied. In both...

Rules of Chemospecificity of Nucleophilc Ring-opening of Dithia-/Oxathia-Phospholane Towards the Selective Synthesis of Nucleoside 5’-O-Pα-Thio/Dithio/Trithio-Phosphate Ester Conjugates

DBU-assisted nucleophilic ring-opening of both uridine-5’-(2-thio-1,3,2-dithia-phospholane), 3, and uridine-(2-thio-1,3,2-oxathia-phospholane), 8, lasted 2 min at RT and resulted in quantitative yields of uridine-5’-phosphoro-di/trithioate esters. Furthermore, it was selective for alcohol and thiol vs. amine nucleophiles. Yet, reaction of mercaptoethanol with 3, was chemo-specific for the oxygen vs. sulfur nucleophile, while for the reaction of mercaptoethanol with 8, the opposite chemo-specificity was observed, probably related to the steric hindrance in the former case. The observed chemospecificity opens facile avenue for the synthesis of nucleoside-5’-O-Pα-thio/dithio/trithio-phosphate ester derivatives

Highly Selective Synthesis of 6-Glyoxylamidoquinoline Derivatives via Palladium-Catalyzed Aminocarbonylation

The aminocarbonylation of 6-iodoquinoline has been investigated in the presence of large series of amine nucleophiles, providing an efficient synthetic route for producing various quinoline-6-carboxamide and quinoline-6-glyoxylamide derivatives. It was shown, after detailed optimization study, that the formation of amides and ketoamides is strongly influenced by the reaction conditions. Performing the reactions at 40 bar of carbon monoxide pressure in the presence of Pd(OAc)2/2 PPh3, the corresponding 2-ketocarboxamides were formed as major products (up to 63%). When the monodentate triphenylphosphine was replaced by the bidentate XantPhos, the quinoline-6-carboxamide derivatives were synthesized almost exclusively under atmospheric conditions (up to 98%). The isolation and characterization of the new carbonylated products of various structures were also accomplished. Furthermore, the structure of three new mono- and double-carbonylated compounds were unambiguously established by using a single-crystal XRD study.

Visible-Light-Mediated Photocatalytic Selective N-Methylation of Amines using CO2 under mild reaction condition via NH2-MIL-125 (Ti) MOF catalyst

We herein describe a facile synthesis method of novel NH2-MIL-125 (Ti) metal organic framework as a photocatalyst, and the photochemical system was firstly developed for the direct N-methylation of amines under very mild reaction conditions of one bar CO2 and NaBH4. According to the optimization of reaction conditions, the selective synthesis of methylamines is achieved in good to excellent conversion and selectivity using visible light mediated photocatalytic system.