HandaPhos: A General Ligand Enabling Sustainable ppm Levels of Palladium-Catalyzed Cross-Couplings in Water at Room Temperature
作者:Sachin Handa、Martin P. Andersson、Fabrice Gallou、John Reilly、Bruce H. Lipshutz
DOI:10.1002/anie.201510570
日期:2016.4.11
complexed in a 1:1 ratio with Pd(OAc)2, enables Pd‐catalyzed cross‐couplings to be run using ≤1000 ppm of this pre‐catalyst. Applications to Suzuki–Miyaura reactions involving highly funtionalized reaction partners are demonstrated, all run using environmentally benign nanoreactors in water at ambient temperatures. Comparisons with existing state‐of‐the‐art ligands and catalysts are discussed herein.
The Hofmann and Curtius rearrangements have been widely used in organicsynthesis and developed for the industrial production (5–100 kg) of pharmaceutically relevant amines/amides. However, the existing use of a stoichiometric organicoxidant [(diacetoxyiodo)benzene or trichloroisocyanuric acid for the Hofmann rearrangement] for amides or an activating reagent (diphenylphosphoryl azide for the Curtius
霍夫曼和库尔蒂斯重排已广泛应用于有机合成,并被开发用于医药相关胺/酰胺的工业生产(5-100 kg)。然而,现有的酰胺化学计量有机氧化剂[(二乙酰氧基碘)苯或三氯异氰脲酸用于霍夫曼重排]或羧酸活化剂(二苯基磷酰叠氮化物用于库尔蒂斯重排)对环境不友好且经济上缺乏吸引力。在此,我们报道了酰胺和醛与过酮和卤化物(和NaN 3)的首次绿色氧化,分别生成N-卤代酰胺和酰基叠氮化物,两者重排成常见的异氰酸酯中间体,随后产生稳定的氨基甲酸酯或脲。霍夫曼和库尔蒂斯重排)当被醇或胺捕获时。每次重新安排都有 30 多个示例,证明这种统一的绿色方法非常高效。重要的是,该方法产生无机无毒K 2 SO 4作为唯一的副产物,这比生产化学计量的、有毒的有机碘苯、氯异氰尿酸或二苯基磷酸的现有方法更有优势。值得注意的是,通过这种绿色氧化库尔蒂斯重排,可以从相应的醛有效合成三种尿素基药物和八种手性尿素催化剂。这种用于霍夫曼和