N-O heterocycle compounds play an important role in various fields. Doyle et al. (Cheng et al., 2017 ) have recently reported an efficient catalyst-controlled selective cyclization reactions of tert -butyldimethylsilyl (TBS)-protected enoldiazoacetamides with nitrosoarenes in which the multifunctionalized products 5-isoxazolones and 1,3-oxazin-4-ones were formed through [3+2]- and [5+1]-cyclizations using Rh 2 (oct) 4 and Rh 2 (cap) 4 as catalysts, respectively. The present work studied the mechanism of the reactions in question and the origins of the catalyst-dependent chemoselectivity by the density functional theory (DFT) calculations at the M06-D3/SMD/6-311+G(d,p)//B3LYP-D3/6-31G(d,p) level of theory. The computed results illustrate the importance of the different dirhodium catalysts to gain diversified N-O heterocycle compounds and suggest the specific interaction between the reactants by the real catalyst model. Meanwhile, it is the steric hindrance and electronic effect of the ligands of dirhodium catalysts that control the reaction mechanism. Furthermore, the other auxiliary theoretical analysis, natural bond orbital calculation and distortion/interaction analysis, make the electronic effects, and steric hindrance more distinct.

The density functional theory investigations were carried out to elucidate the mechanism and the origin of regioselectivity for the Pd(OAc) 2 -catalyzed carbon−oxygen bond activation in the reaction between 4-phenoxy-N-(quinolin-8-yl) butanamide and N-methylindole. The reaction proceeded through four main stages in succession: C−H activation, β-O elimination, nucleo-palladation of the new C−C bond formation, and proto-depalladation steps. A total of six pathways were considered since there were two possible forms of C−O bond breaking in the β-O elimination step and six reaction channels of nucleophilic attack in the crucial nucleo-palladation step. The computational results indicate that the common first step (C−H bond activation step) occurs via a concerted metalation deprotonation (CMD) mechanism. The nucleo-palladation was the rate-determining step for all six reaction pathways. The results also show that the most favorable pathway for the whole reaction is the one (denoted as path b1) in which phenol was removed in the second stage and the hydrogen atom of N-methylindole attacked the oxygen atom of acetate group of the intermediate in the third stage. According to the analyses of noncovalent interaction (NCI) and the reduced density gradient (RDG), the most favored pathway benefits from the strong attractive interaction and weak repulsive interaction in its key transition state. Furthermore, structural, natural bond orbital charge, and energy analyses of the transition states reveal the origin of the regioselectivity. This is a good explanation of the experimental phenomenon and benefits future design of a new strategy for a similar reaction.

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Employability not only refers to the first time be hired ability, but also should include future career development of the relevant quality employee. Based on the data of University Business Majors, this paper used the AHP structural to analyze characteristics of college students the ability to employ. Business students' employability competencies include four dimensions of basic ability, psychological quality, professional knowledge and skills, Yuan skills. Yuan skills are the key element of which affect the ability to form Students may employ, followed by professional knowledge and skills, psychology and basic skills and Yuan skills need to be improved. At the same time, professional knowledge and skills is weak and all of those are not conducive to the initial employment and career development of college students.