ArCH(OMe)?--a Pt(IV)-catalyst originator for diverse annulation catalysis.

ABSTRACT: We discover an important property of a small molecule ArCH(OMe)? which transforms catalytically inactive Pt(II)Br? procatalyst in situ to an powerful catalyst Pt(IV)-species for diverse annulation reaction. The powerful catalytic system enables selective activation of C?-H/N-H and C?-H/C?-H of acetoacetanilide and C=O/C?C of substituted butyne-1,2-dione for C-C/C-N, C-C/C-C and C-O/C-O bond-forming inter- and intramolecular annulation towards direct syntheses of functionalised 2-pyridones, cyclohexenones and 3(2H)-furanones respectively. In contrast to the common ligand, herein highly labile C-OMe bond of ArCH(OMe)? is expected to react with PtBr? towards generation of the high-valent active catalyst. Unlike catalyst promoter or initiator, the reaction does not occur with PtBr? in the absence of ArCH(OMe)?. In situ generation of Pt(IV)-species and -OMe fragment of ArCH(OMe)? were confirmed from the UV-vis characteristic peaks about 260?nm and trapping of -OMe group respectively. These observations provide new prospects and perspectives in catalysis for innovative catalyst design.

SUBMITTER: Ghosh S 

PROVIDER: S-EPMC3798883 | biostudies-other | 2013

REPOSITORIES: biostudies-other