Theoretical and Computational Chemistry Laboratory, Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
J Mol Graph Model. 2023 May;120:108421. doi: 10.1016/j.jmgm.2023.108421. Epub 2023 Jan 23.
The [3 + 2] cycloaddition (32CA) reaction of benzonitrile oxide (BNO) with 4-substituted 4-hydroxy-2-cyclopentenone has been investigated using molecular electron density theory (MEDT) at the Density Functional Theory (DFT) B3LYP/6-31G (d), M06/6-311G (d,p) and M06-2X/6-311++G (d,p) levels. The present theoretical computations indicate that the reaction of BNO with 4-substituted 4-hydroxy-2-cyclopentenones is via [3 + 2] cycloaddition, where the three atom component (TAC) chemo-selectively adds across the alkene functionality in the 2-cyclopentenones (Path A). Analysis of the electrophilic P and nucleophilic P Parr functions at the different reaction sites in the alkene counterpart indicates that the aryl nitrile oxides add across the atomic centers with the highest Mulliken atomic spin densities. The results reported in this study are in good agreement with previous experimental work. The GEDT calculations unravel the low polar character of the [3 + 2] cycloaddition reactions. This reaction occurs with poor enantioselectivity, but a high degree of stereo-, peri-, diastereo, and regioselectivity is seen for the reaction of the BNO with 4-hydroxy-4-methyl-2-cyclopentenones. The regioselectivity of the reactions is the same in all the solvents investigated.
苯甲腈氧化物（BNO）与 4-取代 4-羟基-2-环戊烯酮的[3+2]环加成（32CA）反应已在密度泛函理论（DFT）B3LYP/6-31G（d）、M06/6-311G（d，p）和 M06-2X/6-311++G（d，p）水平上通过分子电子密度理论（MEDT）进行了研究。目前的理论计算表明，BNO 与 4-取代 4-羟基-2-环戊烯酮的反应是通过[3+2]环加成进行的，其中三原子组分（TAC）选择性地在 2-环戊烯酮的烯烃官能团上加成（Path A）。在烯烃对应物的不同反应位点分析亲电 P 和亲核 P Parr 函数表明，芳基腈氧化物通过原子自旋密度最高的原子中心加成。本研究报告的结果与先前的实验工作吻合良好。GEDT 计算揭示了[3+2]环加成反应的低极性特征。该反应的对映选择性差，但 BNO 与 4-羟基-4-甲基-2-环戊烯酮的反应具有高度的立体、周、非对映和区域选择性。在所有研究的溶剂中，反应的区域选择性是相同的。
