Fabrication and Diverse Ring-Expansion Nanocatalysis of Functionalized Pt-Nanoparticles to a General Synthesis of Pyrrolines: A 3D-Mid-IR Study

• Published in: Industrial & engineering chemistry research Vol. 56; no. 42; pp. 12056 - 12069
• Main Authors: Ghosh, Subhadeep, Debnath, Sudipto, Das, Uttam K, Maiti, Dilip K
• Format: Journal Article
• Language: English
• Published: American Chemical Society 25-10-2017
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.7b02441

An unprecedented nanofabrication of functionalized Pt-NPs under mild conditions was accomplished through oxidative insertion of PtBr2 into the O–C bond of ArCH­(OMe)2. TEM and SEM imaging, EELS, XPS, and ESI–MS analyses found the NPs possessing the molecular formula Br2(MeO)­PtIVCH­(OMe)­Ph and low-dimensional spherical morphology. Ketone and amide functionality-bearing electrophilic cyclopropanes underwent ring-opening cyclization. Size-dependent catalytic activity of the NPs was investigated using stabilizers and newly introduced PhCH­(OMe)2 during the synthesis of 2-pyrrolines. The organometallic-NPs were effective for cyclopropane ring-expansion using propargyl amine to 1-pyrrolines with depropargylation. Interestingly, the diverse catalytic activity of the Pt-NPs was effective for sp3C–H activated dual cyclization for the direct synthesis of fused-pyrrolo­[3,2-c]­pyridones. The possible reaction pathway was investigated by 3D-mid-IR-ATR, control experiments, and ESI–MS analyses. The NPs were superior in terms of simple preparation, low catalyst loading, ease of recovery, recycling, diverse catalytic activity, and outstanding ability for the general synthesis of pyrroline analogues.