Iron-Catalyzed Tertiary Alkylation of Terminal Alkynes with 1,3-Diesters via a Functionalized Alkyl Radical
Ming-Qing Tian,a,+ Zhen-Yao Shen,a,+ Xuefei Zhao,a Patrick J. Walsh,b,* and Xu-Hong Hua,*
aInstitute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816 (China)
bRoy and Diana Vagelos Laboratories, Penn/Merck Laboratory for High-Throughput Experimentation, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104 (USA)
+These authors contributed equally.
Abstract: Direct oxidative C(sp)-H/C(sp3)-H cross-coupling offers an ideal and environmentally benign protocol for C(sp)-C(sp3) bond formations. As such, reactivity and site-selectivity with respect to C(sp3)-H bond cleavage have remained a persistent challenge. Herein is reported a simple method for iron-catalyzed/silver-mediated tertiary alkylation of terminal alkynes with readily available and versatile 1,3-dicarbonyl compounds. The reaction is suitable for an array of substrates and proceeds in a highly selective manner even employing alkanes containing other tertiary, benzylic, and C(sp3)-H bonds alpha to heteroatoms. Elaboration of the products enables the synthesis of a series of versatile building blocks. Control experiments implicate the in situ generation of a tertiary carbon-centered radical species.
Angew. Chem. Int. Ed., Doi: 10.1002/anie.202100641 (2019年影响因子:12.959)
论文链接:https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.202100641