Department of Chemistry and Chemical Biology , Cornell University , Ithaca , New York 14853 , United States.
J Am Chem Soc. 2018 Nov 7;140(44):14836-14843. doi: 10.1021/jacs.8b08605. Epub 2018 Oct 26.
Alkyl chlorides are common functional groups in synthetic organic chemistry. However, the engagement of unactivated alkyl chlorides, especially tertiary alkyl chlorides, in transition-metal-catalyzed C-C bond formation remains challenging. Herein, we describe the development of a Ti-catalyzed radical addition of 2° and 3° alkyl chlorides to electron-deficient alkenes. Mechanistic data are consistent with inner-sphere activation of the C-Cl bond featuring Ti-mediated Cl atom abstraction. Evidence suggests that the active Ti catalyst is generated from the Ti precursor in a Lewis-acid-assisted electron transfer process.
烷基氯是合成有机化学中常见的官能团。然而，在过渡金属催化的 C-C 键形成中，未活化的烷基氯，特别是叔烷基氯的参与仍然具有挑战性。在此，我们描述了 Ti 催化的 2°和 3°烷基氯与缺电子烯烃的自由基加成反应的发展。机理数据与 C-Cl 键的内球活化一致，表现为 Ti 介导的 Cl 原子的攫取。有证据表明，活性 Ti 催化剂是由 Ti 前体在路易斯酸辅助的电子转移过程中生成的。
