Direct activation of sp2 C–H bonds by a palladium catalyst has received significant attention in organic chemistry. However, most of these C–Hactivation reactions are carried out in hazardous solvents. Herein we report a novel solvent-free direct sp2 C–Hbond functionalization (oxygenation) method using Pd(II)/Al2O3 catalysis of oxo-benzoxazine derivatives with good to excellent yields, and demonstrate
钯催化剂直接活化sp 2 C-H键在有机化学中受到了广泛关注。然而,大多数这些 C-H 活化反应是在危险溶剂中进行的。在此,我们报道了一种使用 Pd( II )/Al 2 O 3催化氧代苯并恶嗪衍生物的新型无溶剂直接 sp 2 C-H 键官能化(氧化)方法,并证明了其在合成药学上重要的化合物。
Synthesis of 2-substituted-4H-3,1-benzoxazin-4-ones
作者:D. I. Bain、R. K. Smalley
DOI:10.1039/j39680001593
日期:——
yield. With 1 mol. of benzoyl chloride, however, a mixture of benzoxazinone and N-benzoylanthranilic acid was obtained. The mechanism of the reaction has been investigated and various 2-substituted-4H-3,1-benzoxazin-4-ones have been prepared and their u.v. spectra recorded.
邻氨基苯甲酸(1摩尔)在吡啶溶液中与苯甲酰氯(2摩尔)反应,以高收率得到2-苯基-4 H -3,1-苯并恶嗪-4-酮。与1摩尔。然而,得到了苯甲酰氯的苯并恶嗪酮和N-苯并氰基邻氨基苯甲酸的混合物。已经研究了反应的机理,并制备了各种2-取代的-4 H -3,1-苯并恶嗪-4-酮,并记录了它们的uv光谱。
Oxidative NHC catalysis for base-free synthesis of benzoxazinones and benzoazoles by thermal activated NHCs precursor ionic liquid catalyst using air as oxidant
作者:Youkang Zhou、Wei Liu、Yuchen Liu、Jiali Guan、Jieying Yan、Jian-Jun Yuan、Duan-Jian Tao、Zhibin Song
DOI:10.1016/j.mcat.2020.111013
日期:2020.8
A reusable thermal activated NHC precursor ionic liquid catalyst ([BMIm](2)[WO4]) has been prepared and developed for the synthesis of nitrogen-containing heterocycles such as benzoxazinones and benzoazoles through imines activation. [BMIm](2)[WO4] exhibited the good activity for the base-free condensation and oxidative NHC catalysis tandem under air atmosphere. The catalyst can be recovered and reused for at least five runs in gram scale synthesis without any decrease in catalytic activity. Furthermore, the control experiments demonstrated that the reaction involved formation of aromatic aldimines, NHC-catalyzed oxidative formation of imidoyl azoliums and intramolecular cyclization to generate the product.
Zhang, Weijiang; Liu, Ruiyan; Cook, James M., Heterocycles, 1993, vol. 36, # 10, p. 2229 - 2236
作者:Zhang, Weijiang、Liu, Ruiyan、Cook, James M.
DOI:——
日期:——
One-Step Synthesis of 4H-3,1-Benzoxazin-4-ones from Weinreb Amides and 1,4,2-Dioxazol-5-ones via Cobalt-Catalyzed C–H Bond Activation
作者:Shigeki Matsunaga、Tatsuhiko Yoshino、Iku Tanimoto、Kentaro Kawai、Akane Sato