Heterocycle Formation via Palladium-Catalyzed Intramolecular Oxidative C−H Bond Functionalization: An Efficient Strategy for the Synthesis of 2-Aminobenzothiazoles
作者:Laurie L. Joyce、Robert A. Batey
DOI:10.1021/ol900958z
日期:2009.7.2
N-Arylthioureas are converted to 2-aminobenzothiazoles via intramolecular C−S bond formation/C−H functionalization utilizing an unusual cocatalytic Pd(PPh3)4/MnO2 system under an oxygen atmosphere at 80 °C. This method eliminates the need for an ortho-halo substituted precursor, instead achieving direct functionalization of the ortho-aryl C−H bond. Mechanistic observations, including a large intramolecular
N-芳硫脲在80℃的氧气气氛下,通过不寻常的助催化Pd(PPh 3)4 / MnO 2系统,通过分子内C-S键形成/ CH-H官能化反应转化为2-氨基苯并噻唑。该方法消除了对需要邻的的卤代取代的前体,而不是实现直接官能邻-芳基C-H键。机械观察,包括5.9的大分子内主要动力学同位素效应,揭示了与亲电性lad裂机制不一致的反应途径。