Highly Efficient and Enantioselective α-Arylation of Cycloalkanones by Scandium-Catalyzed Diazoalkane-Carbonyl Homologation
作者:Jason Kingsbury、Victor Rendina、Hilan Kaplan
DOI:10.1055/s-0031-1289650
日期:2012.3
Functionalized α-tertiary and -quaternary 2-arylcycloalkanones are rapidly accessed by scandium(III) triflate-catalyzed diazoalkane-carbonyl homologations. Recent developments have allowed for carbon insertion reactions to be performed with catalyst loadings as low as 0.5 mol% on scales up to 5 mmol. Pairing readily available bis- and tris(oxazoline) based ligands with scandium triflate allows access to arylated medium ring carbocycles with enantioselectivities up to 98:2 er and >98% yield. The formal C-C insertion of aryldiazomethanes into unsubstituted cycloalkanones provides a single-step solution to the ongoing challenge of α-arylation.
功能化的α-叔和α-季2-芳基环烷酮通过三氟甲磺酸钪(III)催化的重氮甲烷-羰基同系化反应迅速获得。最近的进展使得碳插入反应能够在催化剂负载量低至0.5 mol%的情况下进行,规模可达5 mmol。结合易于获得的基于双和三噁唑啉的配体与三氟甲磺酸钪,可以合成具有高达98:2 对映体比和>98%产率的芳基化中环碳环。芳基重氮甲烷在无取代环烷酮中的正式C-C插入提供了一种一步解决α-芳基化持续挑战的方法。