Experimental and Theoretical Investigation of the Synchronicity of Ambident Silyloxypyrone-Based (5 + 2) Cycloadditions
作者:Adam J. Youman、Samantha N. Rokey、Jacob P. Grabowski、Wentao Guo、Qing Sun、Susanna N. Angles、John R. Goodell、Dean J. Tantillo、T. Andrew Mitchell
DOI:10.1021/acs.joc.3c00318
日期:2023.5.5
silyloxypyrone-based (5 + 2) cycloadditions was determined to be extremely dependent on the nature of the dipolarophile. Neutral alkenes were the least reactive, whereas both electron-deficient and electron-rich dipolarophiles were more reactive, thus providing evidence for ambident oxidopyrylium intermediates. Qualitative rate studies, Hammett linear free energy relationships, and theoretical calculations combined
基于甲硅烷氧基吡喃酮的 (5 + 2) 环加成的反应途径被确定为极其依赖于偶极试剂的性质。中性烯烃的反应性最低,而缺电子和富电子的偶极分子反应性更强,从而为氧化吡啶中间体的存在提供了证据。定性速率研究、Hammett 线性自由能关系和理论计算相结合,为通过协调和逐步边界的一系列反应性提供了证据。