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Herein, we disclose a ruthenium-catalyzed meta -selective C-H activation of phosphines by using intrinsic P (III) as a directing group. 2,2,6,6-Tetramethylheptane-3,5-dione acts as the ligand and exhibits an excellent performance in boosting the meta -alkylation. The protocol allows an efficient and straightforward synthesis of meta -alkylated tertiary phosphines. Several meta -alkylated phosphines were evaluated for Pd-catalyzed Suzuki coupling and found to be superior to commercially available ortho -substituted phosphines. The practicability of this methodology is further demonstrated by the synthesis of difunctionalized phosphines.

Biphenylcarboxylic acid with two competing C(sp 2 )-H sites was designed for site selective C(sp 2 )-H functionalization by developing carboxylic acids assisted remote and selective olefination via 7-membered palladacycle. Mechanism investigation and DFT calculations reveal a kinetics-determined process, which could be utilized to explore a variety of remote site selectivity. The practicability of this method was highlighted by the precise construction of phenathrene under sequential site selectivity.

An original Pd(II)-catalyzed domino two C-H activations strategy has been designed to synthesize pyrano[4,3- b]indol-1(5 H)-one motifs from inexpensive and commercially available olefins and heteroaromatic acids by carboxylate-directed sequential ortho-C-H alkenylation and remote C-H lactonization. Importantly, this protocol overcomes the selectivity for carboxylic acids with acrylates of the conventional Michael addition-type process. Preliminary studies of mechanism indicate that both aryl and olefinlic C-H activations may participate in this catalytic system.