RESUMO
We apply the macroscopic fluctuation theory to analyze the long-time statistics of the position of a tracer in the dense and the dilute limits of diffusive single-file systems. Our explicit results are about the corresponding large deviation functions for an initial step density profile with the fluctuating (annealed) and the fixed (quenched) initial conditions. These hydrodynamic results are applicable for a general single-file system and they agree with recent exact results obtained by microscopic solutions for specific model systems.
RESUMO
The catalytic conversion of ketones to esters via C(O)-C bond cleavage under transition-metal free conditions is reported. This catalytic process proceeds under solvent-free conditions and offers an easy operational procedure, broad substrate scope with excellent selectivity, and reaction scalability.
RESUMO
Herein we report an efficient manganese-catalyzed C-alkylation of unactivated amides and tert-butyl acetate using alcohols as alkylating agents. This elegant approach exhibits a broad substrate scope providing the C-C coupled products of amides via a hydrogen auto-transfer strategy using aryl, heteroaryl, and aliphatic alcohols.
RESUMO
A transition-metal-catalyzed borrowing hydrogen/hydrogen auto-transfer strategy allows the utilization of feedstock alcohols as an alkylating partner, which avoids the formation of stoichiometric salt waste and enables a direct and benign approach for the construction of C-N and C-C bonds. In this study, a nickel-catalyzed α-alkylation of unactivated amides and ester (tert-butyl acetate) is carried out by using primary alcohols under mild conditions. This C-C bond-forming reaction is catalyzed by a new, molecularly defined nickel(II) NNN-pincer complex (0.1-1â mol %) and proceeds through hydrogen auto-transfer, thereby releasing water as the sole byproduct. In addition, N-alkylation of cyclic amides under Ni-catalytic conditions is demonstrated.
RESUMO
Here, the first example is reported of a new, molecularly defined SNS-cobalt(ii) catalyst for the acceptorless dehydrogenative coupling (ADC) of unprotected amino alcohols with secondary alcohols leading to pyrrole and pyridine derivatives.
RESUMO
Here, we report a ligand- and reductant-free nickel-catalyzed N-vinylation of heteroaromatic amines using biorenewable p-cymene as a solvent. This unprecedented cross-coupling strategy has high functional group tolerance (halides, alkoxy, cyano, chiral motif, etc.) and proceeded via C-H bond activation.
RESUMO
We report here for the first time the catalytic oxidative dehydrogenation of N-heterocycles by a visible-light organo-photoredox catalyst with low catalyst loading (0.1-1â mol %). The reaction proceeds efficiently under base- and additive-free conditions with ambient air at room temperature. The utility of this benign approach is demonstrated by the synthesis of various pharmaceutically relevant N-heteroarenes such as quinoline, quinoxaline, quinazoline, acridine, and indole.
RESUMO
A catalytic method for functional group interconversion is immensely important in modern sciences. Here, we report an efficient catalytic conversion of nitroalkenes to highly stereoselective 1-trifluoromethylalkenes at room temperature. This unprecedented metal-free photocatalytic strategy is simple and operates under visible-light irradiation using the commercially available CF3 source.
RESUMO
A unified strategy for cobalt-catalyzed ortho-C-H bond alkynylation of benzylamines is reported. Simple, commercially available CoBr2 was used as a cobalt source. The developed alkynylation strategy is robust and efficient and has a broad substrate scope including 1°, 2°, and 3° benzylamines. The mechanistic study shows that C-H bond cleavage is reversible, and the kinetic study illustrates that the rate of reaction depends solely on the catalyst.