Borylation of Unactivated C(sp<sup>3</sup>)–H Bonds with Bromide as a Traceless Directing Group
作者:Ge Zhang、Meng-Yao Li、Wen-Bo Ye、Zhi-Tao He、Chen-Guo Feng、Guo-Qiang Lin
DOI:10.1021/acs.orglett.1c00617
日期:2021.4.16
A palladium-catalyzed alkyl C–H borylation with bromide as a tracelessdirectinggroup is described, providing a convenient approach to access alkyl boronates bearing a β-all-carbon quaternary stereocenter. The protocol features a broad substrate scope, excellent site selectivity, and good functional group tolerance.
Palladium-catalyzed cross-coupling of unreactive C(sp<sup>3</sup>)–H bonds with azole C(sp<sup>2</sup>)–H bonds by using bromide as a traceless directing group
A palladium-catalyzed intermolecular cross-coupling of unreactive C(sp3)–Hbonds and azole C(sp2)–Hbonds with bromide as a traceless directing group is described. The judicious selection of the bulky and electron-rich phosphine ligand is the key for the success of this cascade process. The protocol features a broad substrate scope, excellent regioselectivity, and good functional group tolerance.
contrast to coupling with carbon nucleophiles, limited examples with heteroatom nucleophiles have been reported. Herein we report a palladium-catalyzedintermolecular C(sp3)–H phosphorylation reaction via 1,4-palladium migration, which is often difficult because of the strong coordination of phosphorus reagents to palladium catalysts. Phosphorylation of C(sp3)–H bonds is accomplished in good reaction yields