| Autor: |
Li, Jianhao, Jiang, Xiaohan, Liang, Zixi, Tang, Chao, Ma, Lishuang, Lin, Xufeng, Liu, Xinmei, Chen, Xuebo |
| Zdroj: |
Physical Chemistry Chemical Physics (PCCP); 11/28/2024, Vol. 26 Issue 44, p28010-28018, 9p |
| Abstrakt: |
Carbenes are highly reactive intermediates central to various organic transformations, particularly within photochemistry. This study investigates siloxy carbenes generated from acyl silanes via a 1,2-silyl shift, focusing on their generation and reactivity in excited states, using the multiconfiguration perturbation theory (CASPT2//CASSCF/PCM). Our findings reveal that the presence of an aryl group conjugated with the carbonyl moiety substantially lowers the excitation energy of the singlet 1nπ* state, enabling the 1,2-Brook rearrangement to proceed directly on the singlet hypersurface. This direct pathway, mediated by singlet SΣP(σ1π1) and S0(σ2π0) carbenes, bypasses the need for intersystem crossing (ISC) to the triplet 3nπ* state, which is the rate-determining step in the stepwise triplet pathway involving a triplet TΣP(σ1π1) carbene, thereby enhancing reaction rates and stereoselectivity by preventing undesired bond rotations. This contribution deepens the understanding of siloxy carbene reactivity and lays the groundwork for their future applications. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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