A palladium NNC-pincer complex: an efficient catalyst for allylic arylation at parts per billion levels.

Allylic arylation of allylic acetates by sodium tetraarylborates in the presence of ppb to ppm (molar) loadings of a palladium NNC-pincer complex catalyst in methanol at 50 degrees C gave the corresponding arylated products in excellent yields. Total turnover numbers of up to 500 000 000 and turnover frequencies of up to 11 250 000 h(-1) were achieved.