Aryl C(sp2)–X Coupling (X = C, N, O, Cl) and Facile Control of N-Mono- and N,N-Diarylation of Primary Alkylamines at a Pt(IV) Center

We present the first example of an unprecedented and fast aryl C(sp 2 )-X reductive elimination from a series of isolated Pt(IV) aryl complexes (Ar = p -FC 6 H 4 ) LPt IV F(py)(Ar)X (X = CN, Cl, 4-OC 6 H 4 NO 2 ) and LPt IV F 2 (Ar)(HX) (X = NHAlk; Alk = n -Bu, PhCH 2 , cyclo-C 6 H 11 , t -Bu, cyclopropylmethyl) bearing a bulky bidentate 2-[bis(adamant-1-yl)phosphino]phenoxide ligand (L). The C(sp 2 )-X reductive elimination reactions of all isolated Pt(IV) complexes follow first-order kinetics and were modeled using density functional theory (DFT) calculations. When a difluoro complex LPt IV F 2 (Ar)(py) is treated with TMS-X (TMS = trimethylsilyl; X= NMe 2 , SPh, OPh, CCPh) it also gives the corresponding products of the Ar-X coupling but without observable LPt IV F(py)(Ar)X intermediates. Remarkably, the LPt IV F 2 (Ar)(HX) complexes with alkylamine ligands (HX = NH 2 Alk) form selectively either mono- (ArNHAlk) or diarylated (Ar 2 NAlk) products in the presence or absence of an added Et 3 N, respectively. This method allows for a one-pot preparation of diarylalkylamine bearing different aryl groups. These findings were also applied in unprecedented mono- and di-N-arylation of amino acid derivatives (lysine and tryptophan) under very mild conditions.