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(sp2)–X reductive elimination from a series of isolated Pt­(IV) aryl complexes (Ar = p-FC6H4) LPtIVF­(py)­(Ar)­X (X = CN, Cl, 4-OC6H4NO2) and LPtIVF2(Ar)­(HX) (X = NHAlk; Alk = n-Bu, PhCH2, cyclo-C6H11, t-Bu, cyclopropylmethyl) bearing a bulky bidentate 2-[bis­(adamant-1-yl)­phosphino]­phenoxide ligand (L). The C­(sp2)–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 LPtIVF2(Ar)­(py) is treated with TMS–X (TMS = trimethylsilyl; X= NMe2, SPh, OPh, CCPh) it also gives the corresponding products of the Ar–X coupling but without observable LPtIVF­(py)­(Ar)­X intermediates. Remarkably, the LPtIVF2(Ar)­(HX) complexes with alkylamine ligands (HX = NH2Alk) form selectively either mono- (ArNHAlk) or diarylated (Ar2NAlk) products in the presence or absence of an added Et3N, 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.