The reason for the site selectivity previously reported for B(C₆F₅)₃-catalyzed C(sp³)–H alkylation of tertiary amines with electron-deficient olefins remains a mystery. The selectivity appears to be governed by the number of electron-withdrawing groups (EWGs) on the olefin: one EWG results in α-alkylation, whereas two EWGs (one on each end of the double bond) result in β-alkylation. In this study, we solved the mystery and unlocked the pathway for β-alkylation with olefins bearing only one EWG. Control experiments and density functional theory calculations provided a detailed picture of the reaction mechanism for both α- and β-alkylation. Furthermore, we demonstrated the broad scope of the β-alkylation reaction.

中文翻译：

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B(C6F5)3-催化叔胺与缺电子烯烃的 C(sp3)–H 烷基化：位点选择性的决定因素

_{先前报道的B(C 6} F ₅ ) ₃催化的叔胺与缺电子烯烃的C(sp ³ )–H烷基化反应具有位点选择性的原因仍然是一个谜。选择性似乎取决于烯烃上吸电子基团 (EWG) 的数量：一个 EWG 导致 α-烷基化，而两个 EWG（双键两端各一个）导致 β-烷基化。在这项研究中，我们解开了这个谜团，并揭示了仅带有一个 EWG 的烯烃进行 β-烷基化的途径。控制实验和密度泛函理论计算提供了α-和β-烷基化反应机理的详细图片。此外，我们证明了β-烷基化反应的广泛范围。