Alkenes and arenes possessing a bidentate directing group are alkylated with a primary or secondary alkylzinchalide in the presence of an iron/diphosphine catalyst and a dichloroalkane oxidant. Acrylamides, including unsubstituted and monosubstituted ones, react stereoselectively. Under these reaction conditions, β‐hydrogen elimination and homocoupling of the organometallic reagent are largely suppressed
Insertion of unsaturated systems such as alkynes and olefins into unactivated sp3 CH bonds remains an unexplored problem. We herein address this issue by successfully incorporating a wide variety of functionalized alkynes and electron‐deficient olefins into the unactivated sp3 CH bond of pivalic acid derivatives with excellent syn‐ and linear‐ selectivity. A strongly chelating 8‐aminoquinoline directing
Co(<scp>iii</scp>)-catalyzed <i>Z</i>-selective oxidative C–H/C–H cross-coupling of alkenes with triisopropylsilylacetylene
作者:Tingxing Zhao、Dekun Qin、Weiguo Han、Shiping Yang、Boya Feng、Ge Gao、Jingsong You
DOI:10.1039/c9cc02347j
日期:——
A Co(III)-catalyzed direct oxidative C–H/C–Hcross-couplingreaction of acrylamides with triisopropylsilylacetylene is presented. It is applicable to unsubstituted, internal and terminal acrylamides with a broad functionality tolerance. The feasibility of this protocol is successfully demonstrated by the late-stage alkynylation of a derivative of steroid drug Epristeride.
The Pd-catalyzed diastereos elective trifluoromethylthiolation of acrylamides was developed to allow the formation of the Z-isomer as a single product. Using a C-H bond functionalization strategy, the method was applied to a broad range of a aryl, alpha-alkyl, and alpha,beta-disubstituted acrylamides bearing the amide derived from the 8-aminoquinoline as a directing group. Mechanistic studies as well as postfunctionalization of the products were performed. This approach opens new routes to unprecedented SCF3-containing scaffolds.
Iron-Catalyzed, Chelation-Induced Remote C–H Allylation of Quinolines via 8-Amido Assistance
作者:Xuefeng Cong、Xiaoming Zeng
DOI:10.1021/ol501534z
日期:2014.7.18
An iron-catalyzed, 8-amido-enabled regiodivergent C-H allylation of quinolines is described. This reaction represents a rare example of chelation-induced geometrically inaccessible C-H functionalization, allowing for the highly regio- and stereoselective preparation of either the C5- or the C4-allylated quinoline scaffolds regiocontrolled by the catalytic systems.