Nickel(II)-Catalyzed Addition of Aryl-, Alkenyl-, and Alkylboronic Acids to Alkenylazaarenes
作者:Xing-Yu Liu、Yun-Xuan Tan、Xin Wang、Hao Xu、Yu-Hui Wang、Ping Tian、Guo-Qiang Lin
DOI:10.1021/acs.orglett.0c01425
日期:2020.5.15
A nickel(II)-catalyzedaddition of aryl-, alkenyl-, and alkylboronic acids to alkenylazaarenes was presented. This reaction exhibited high efficiency (up to 93% yield), a broad substrate scope (seven types of heterocycles), and good functional group compatibility. The resulting products can be further transformed to many useful building blocks. Finally, the preliminary studies suggested that the adjacent
Coordination‐Controlled Nickel‐Catalyzed Benzylic Allylation of Unactivated Electron‐Deficient Heterocycles
作者:Pengpeng Zhang、Jin Wang、Zoe R. Robertson、Timothy R. Newhouse
DOI:10.1002/anie.202200602
日期:2022.5.23
A nickel-catalyzed benzylic allylation and benzylation of 14 types of unactivated heterocyclic aromatic compounds is described. The selective deprotonation of benzylic sites is hypothesized to be controlled by the original coordination of a heterocyclic nitrogen to Zn(TMP)2. In addition to the pro-nucleophiles, readily available bromide and chloride electrophiles could be used.
Aryl-Nickel-Catalyzed Benzylic Dehydrogenation of Electron-Deficient Heteroarenes
作者:Pengpeng Zhang、David Huang、Timothy R. Newhouse
DOI:10.1021/jacs.9b12706
日期:2020.1.29
This manuscript describes the first practical benzylic dehydrogenation of electron-deficient heteroarenes, including pyridines, pyrazines, pyrimidines, pyridazines, and triazines. This transformation allows for the efficient benzylic oxidation of heteroarenes to afford heterocyclic styrenes by the action of nickel catalysis paired with an unconventional bromothiophene oxidant.
Enantioselective Alkylation of 2-Alkylpyridines Controlled by Organolithium Aggregation
作者:Joshua J. Gladfelder、Santanu Ghosh、Maša Podunavac、Andrew W. Cook、Yun Ma、Ryan A. Woltornist、Ivan Keresztes、Trevor W. Hayton、David B. Collum、Armen Zakarian
DOI:10.1021/jacs.9b08659
日期:2019.9.25
pyridines provides access to chiral pyridines via an opera- tionally simple protocol that obviates the need for prefunc- tionalization or preactivation of the substrate. The alkylation is accomplished using chiral lithium amides as non-covalent stereodirecting auxiliaries. Crystallographic and solution NMR studies provide insight into the structure of well- defined chiral aggregates in which a lithium