title: Predesigned Metal-Anchored Building Block for In Situ Generation of Pd Nanoparticles in Porous Covalent Organic Framework: Application in Heterogeneous Tandem Catalysis.
abstract: The development of nanoparticle-polymer-hybrid-based heterogeneous catalysts with high reactivity and good recyclability is highly desired for their applications in the chemical and pharmaceutical industries. Herein, we have developed a novel synthetic strategy by choosing a predesigned metal-anchored building block for in situ generation of metal (Pd) nanoparticles in the stable, porous, and crystalline covalent organic framework (COF), without using conventional reducing agents. In situ generation of Pd nanoparticles in the COF skeleton is explicitly confirmed from PXRD, XPS, TEM images, and15N NMR spectral analysis. This hybrid material is found to be an excellent reusable heterogeneous catalyst for the synthesis of biologically and pharmaceutically important 2-substituted benzofurans from 2-bromophenols and terminal alkynes via a tandem process with the turnover number up to 1101. The heterogeneity of the catalytic process is unambiguously verified by a mercury poisoning experiment and leaching test. This hybrid material shows superior catalytic performance compared to commercially available homogeneous as well as heterogeneous Pd catalysts.
authors.affiliation: Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India.|Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India.
authors.forename: Mohitosh
authors.initials: M
authors.lastname: Bhadra
authors.affiliation: Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India.|Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India.
authors.forename: Himadri Sekhar
authors.initials: HS
authors.lastname: Sasmal
authors.affiliation: Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India.
authors.forename: Arghya
authors.initials: A
authors.lastname: Basu
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India.|CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India.
authors.forename: Siba P
authors.initials: SP
authors.lastname: Midya
authors.affiliation: Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India.|Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India.
authors.forename: Sharath
authors.initials: S
authors.lastname: Kandambeth
authors.affiliation: Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India.
authors.forename: Pradip
authors.initials: P
authors.lastname: Pachfule
authors.affiliation: Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India.|CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India.
authors.forename: Ekambaram
authors.initials: E
authors.lastname: Balaraman
authors.affiliation: Physical/Materials Chemistry Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune-411008, India.|Academy of Scientific and Innovative Research (AcSIR) , New Delhi-110020, India.
authors.forename: Rahul
authors.identifier: http://orcid.org/0000-0002-3547-4746
authors.initials: R
authors.lastname: Banerjee
keywords: Pd nanoparticles; benzofuran; covalent organic frameworks; in situ synthesis; tandem catalysis