A rhodium-catalyzed C–H functionalization with activated amides by decarbonylation has been developed. Notably, this is the first C–H arylation employing N-acylsaccharins as coupling partners to give biaryls in good to excellent yields. The highlight of the work is the high tolerance of functional groups such as formyl, ester, and vinyl and the use of a removable directing group.
Palladium(II)-Catalyzed ortho Arylation of 2-Phenylpyridines with Potassium Aryltrifluoroborates by C-H Functionalization
作者:Ming-Jung Wu、Jean-Ho Chu、Shiang-Lin Tsai
DOI:10.1055/s-0029-1217014
日期:2009.11
4-dioxane at 120 ˚C for 24 hours. p-Benzoquinone is an important co-oxidant in the transmetalation-reductive elimination step. The kinetic isotope effect (k H/k D) for the C-H bond activation was determined to be 1.09. It indicates that the C-H bond cleavage does not occur in the rate-determining step. C-H functionalization - potassium trifluoroborate - palladium catalyst - arylations - pyridines
提出了通过使用芳基三氟硼酸钾有效地一锅合成邻芳基化的2-苯基吡啶和吡啶衍生物。最佳反应条件如下:在10摩尔%的乙酸钯(II),三当量的乙酸铜(II)和两当量的乙酸铜存在下,用2.5当量的芳基三氟硼酸钾处理2-苯基吡啶或吡啶衍生物。对苯醌在1,4-二恶烷中的溶液在120°C下保持24小时。对苯醌是在金属转移-还原消除步骤中的重要助氧化剂。动力学同位素效应(k H / k D对于CH键的活化确定为1.09。这表明在速率确定步骤中没有发生CH键断裂。 CH官能化-三氟硼酸钾-钯催化剂-芳基化-吡啶