Manganese catalyzed urea and polyurea synthesis using methanol as C1 source

The manganese-catalyzed dehydrogenative coupling between methanol and amines for the synthesis of ureas and polyureas is described. Importantly, catalytic efficiency can be improved by the newly synthesized MACHO ligands. Furthermore, this highly atom-economical protocol demonstrates a broad substrate scope with good functional group tolerance, producing H_(2)as the sole byproduct. Mechanistic studies disclose that formamide is formed through manganese-catalyzed formylation of amine with methanol.Subsequent dehydrogenation affords a transient isocyanate, which is attacked by another equivalent of amine to provide the final product.

Electrochemical utilization of methanol and methanol-d4 as a C1 source to access(deuterated) 2,3-dihydroquinazolin-4(1H)-one

Herein, an electrocatalytic protocol for the synthesis of 2,3-dihydroquinazolin-4(1H)-one has been disclosed. Methanol is activated and utilized as the C1 source to cyclize with 2-aminobenzamides.This cyclization reaction proceeds conveniently(room temperature and air atmosphere) without any homogeneous metal catalysts, external oxidants, or bases. A wide variety of N,N-disubstituted 2,3-dihydroquinazolin-4(1H)-ones are obtained via this approach. Moreover, when methanol-d4is used, a deuterated methylene motif is incorporated into the N-heterocycles, providing an efficient approach to the deuterated N-heterocycles.

Measurement of(n,α)and(n,2n)reaction cross sections at a neutron energy of 14.92±0.02 MeV for potassium and copper with uncertainty propagation

Experimentally measured neutron activation cross sections are presented for the ^(65)Cu(n,0)^(62m)Cu,^(41) K(n,a)^(38C)l,and ^(65)Cu(n.2n)^(64)Cu reactions with detailed uncertainty propagation.The neutron cross secions were measured at an incident energy of 14.92±0.02 MeV,and the neutrons were based on the(d,n)a fusion reaction.The ^(27) Al(n,a)^(24)Na reaction was used as a reference reaction for the normalization of the neutron flux.The pre-calib-rated lead-shielded HPGe detector was used to detect the residues'γ-ray spetra.The data from the measured cross sections are compared to the previously measured cross sections from the EXFOR database,theoretically calculated cross sections using the TALYS and EMPIRE codes,and evaluated nuclear data.