Iridium-catalysed borylation of sterically hindered C(sp<sup>3</sup>)–H bonds: remarkable rate acceleration by a catalytic amount of potassium tert-butoxide
The C(sp(3))-H bonds located on the methyl groups of an isopropyl group participate in iridium-catalysed C-H borylation with bis(pinacolato)diboron via a significant rate acceleration caused by a catalytic amount of t-BuOK.
β-C–H bonds in saturated heterocycles. Science, this issue p. 736 A methylphenanthroline iridium catalyst rapidly adds boron to primary C–Hbonds and beta C–Hbonds in saturated heterocycles. The selective functionalization of strong, typically inert carbon-hydrogen (C–H) bonds in organic molecules is changing synthetic chemistry. However, the undirected functionalization of primary C–Hbonds without
Copper-Mediated Dehydrogenative C(sp<sup>3</sup>)–H Borylation of Alkanes
作者:Ruocheng Sang、Wangyujing Han、Hanwen Zhang、Carla M. Saunders、Adam Noble、Varinder K. Aggarwal
DOI:10.1021/jacs.3c02185
日期:2023.7.19
Borylations of inert carbon–hydrogen bonds are highly useful for transforming feedstock chemicals into versatile organoboron reagents. Catalysis of these reactions has historically relied on precious-metal complexes, which promote dehydrogenative borylations with diboron reagents under oxidant-free conditions. Recently, photoinduced radical-mediated borylations involving hydrogen atom transfer pathways
Iron-Catalyzed C(Sp<sup>3</sup>)–H Borylation, Thiolation, and Sulfinylation Enabled by Photoinduced Ligand-to-Metal Charge Transfer
作者:Jia-Lin Tu、Ao-Men Hu、Lin Guo、Wujiong Xia
DOI:10.1021/jacs.3c01082
日期:——
(LMCT) process. These reactions exhibit remarkably broad substrate scope (>150 examples in total), and most importantly, all of these three reactions show unconventional regioselectivity, with the occurrence of C(sp3)–H borylation, thiolation, and sulfinylation preferentially at the distal methyl position. The procedures are operationally simple and readily scalable and provide access to high-value products
Iridium-Catalyzed Borylation of Secondary C–H Bonds in Cyclic Ethers
作者:Carl W. Liskey、John F. Hartwig
DOI:10.1021/ja305596v
日期:2012.8.1
The borylation of secondary C-H bonds, specifically secondary C-H bonds of cyclic ethers, with a catalyst generated from tetramethylphenanthroline and an iridium precursor is reported. This borylation occurs with unique selectivity for the C-H bonds located beta to the oxygen atoms over the weaker C-H bonds located alpha to oxygen atoms. Mechanistic studies imply that the C-H bond cleavage occurs directly at the beta position rather than at the alpha position followed by isomerization of a reaction intermediate.