Supported Nickel Nanoparticles as Catalyst in Direct sp3 C−H Alkylation of 9H-Fluorene Using Alcohols as Alkylating Agent

Abstract

Herein, we report an inexpensive first-row transition metal Ni heterogeneous catalytic system for the Csp3-mono alkylation of fluorene using alcohols as alkylating agents via borrowing hydrogen strategy. The catalytic protocol displayed versatility with high yields of the desired products using various types of primary alcohols, including aryl/hetero aryl methanols, and aliphatic alcohols as alkylating agents. The catalyst Ni NPs@N−C was synthesized via high-temperature pyrolysis strategy, using ZIF-8 as the sacrificial template. The Ni NPs@N−C catalyst was characterized by XPS, HR-TEM, HAADF-STEM, XRD and ICP-MS. The catalyst is stable even in the air at room temperature, displayed excellent activity and could be recycled 5 times without appreciable loss of its activity.