Al(OTf)3 exhibits superior catalyst performance in the Friedel–Crafts‐type benzylation using benzylicphosphate as an electrophile. The reaction can be conducted even with 0.2 mol‐% of the catalyst. Twenty‐one different diarylmethanes are formed. The chemoselective property of the catalyst toward the phosphate group over acetate and bromide is noteworthy.
An efficient approach to the benzylation of arenes has been developed. The reactions described provide straightforward access to diarylmethanes through Pd-catalyzed coupling of benzylic phosphates with arylsilanes in good to excellent yields. The reaction tolerates a wide range of functionalities such as halide, alkoxyl, and nitro groups.
C–H Bond Arylations and Benzylations on Oxazol(in)es with a Palladium Catalyst of a Secondary Phosphine Oxide
作者:Lutz Ackermann、Sebastian Barfüsser、Christoph Kornhaass、Anant R. Kapdi
DOI:10.1021/ol200986x
日期:2011.6.17
An air-stable, well-defined palladium complex derived from secondary phosphine oxide (SPO) (1-Ad)(2)P(O)H enabled efficient C-H bond functionalizations with ample scope, which set the stage for direct arylations and benzylations of (benz)oxazoles, as well as unprecedented palladium-catalyzed C-H bond arylations on nonaromatic oxazolines.