A nickel‐catalyzed three‐component reaction involving terminal alkynes, boronic acids, and alkyl halides is presented herein. Trisubstituted alkenes can be obtained in a highly regio‐ and stereocontrolled manner by the simultaneous addition of both aryl and alkylgroups across the triple bond in a radical‐mediated process. The reaction, devoid of air‐ and moisture‐sensitive organometallic reagents
ruthenium-catalyzed meta-selective C–H activation of phosphines by using intrinsic P(III) as a directing group. 2,2,6,6-Tetramethylheptane-3,5-dione acts as the ligand and exhibits an excellent performance in boosting the meta-alkylation. The protocol allows an efficient and straightforward synthesis of meta-alkylated tertiaryphosphines. Several meta-alkylated phosphines were evaluated for Pd-catalyzed Suzuki coupling
Iron-catalyzed regioselective alkylation of 1,4-quinones and coumarins with functionalized alkyl bromides
作者:Dengke Li、Xianfu Shen
DOI:10.1039/c9ob02289a
日期:——
A simple and efficient Fe-catalyzed regioselectivealkylation of 1,4-quinones and coumarins, using functionalized alkyl bromides as alkylating reagents, has been developed. The reaction proceeds under mild conditions with the addition of alkyl bromides to a wide range of 1,4-quinone and coumarin derivatives with a broad substrate scope and wide functional group tolerance to provide the products in
Nickel-Catalyzed Heck-Type Alkenylation of Secondary and Tertiary α-Carbonyl Alkyl Bromides
作者:Chao Liu、Shan Tang、Dong Liu、Jiwen Yuan、Liwei Zheng、Lingkui Meng、Aiwen Lei
DOI:10.1002/anie.201108350
日期:2012.4.10
Ni made it! A novel Heck‐type reaction of secondary and tertiary α‐carbonyl alkyl bromides, most likely involving a radical process, was achieved through the use of a nickel catalyst. Various substituted styrenes and 1,1‐diaryl alkenes were utilized as substrates to easily construct α‐alkenyl carbonyl compounds with tertiary or quaternary carbon centers. A catalytic cycle involving NiI/NiII is proposed
倪做到了!通过使用镍催化剂,实现了仲和叔α-羰基烷基溴化物的新型Heck型反应,最有可能涉及自由基过程。各种取代的苯乙烯和1,1-二芳基烯烃被用作底物,以轻松构建具有叔碳或季碳中心的α-烯基羰基化合物。基于我们的实验结果,提出了涉及Ni I / Ni II的催化循环。EWG =吸电子基团。
A Pyridine-Based Donor–Acceptor Molecule: A Highly Reactive Organophotocatalyst That Enables the Reductive Cleavage of C–Br Bonds through Halogen Bonding
作者:Natsuki Kato、Takeshi Nanjo、Yoshiji Takemoto
DOI:10.1021/acscatal.2c02067
日期:2022.7.1
direct, photocatalytic reductive cleavage of the C–Br bond. A wide variety of alkyl bromides including unactivated ones can be used under ambient conditions without any additional activating agents to give the C–C coupling products in good yield. Mechanistic studies indicated that the photocatalyst interacts with alkyl bromides throughhalogenbonding and that the pyridine moiety is important for the progress