Electrophilic C(sp²)–H Cyanation with Inorganic Cyanate (OCN⁻) by Pᴵᴵᴵ/Pⱽ=O-Catalyzed Phase Transfer Activation

A catalytic method for the direct electrophilic cyanation of C(sp²)–H nucleophiles with sodium cyanate (NaOCN) is reported. Mechanistic experiments show that under solid-liquid phase transfer, an inorganic cyanate is activated by halide displacement on a halophosphonium. Redox catalysis is enabled b...

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Bibliographic Details
Main Author: Hu, Shicheng
Other Authors: Radosevich, Alexander T.
Format: Thesis
Published: Massachusetts Institute of Technology 2024
Online Access:https://hdl.handle.net/1721.1/157726
Description
Summary:A catalytic method for the direct electrophilic cyanation of C(sp²)–H nucleophiles with sodium cyanate (NaOCN) is reported. Mechanistic experiments show that under solid-liquid phase transfer, an inorganic cyanate is activated by halide displacement on a halophosphonium. Redox catalysis is enabled by the usage of a strained phosphine (phosphetane) so that catalyst turnover from phosphine oxide to phosphine can be easily achieved by the usage of a terminal hydrosilane reductant. These results demonstrate the feasibility of deoxyfunctionalization of insoluble inorganic salts by Pᴵᴵᴵ/Pⱽ=O catalyzed phase transfer activation, as exemplified by C(sp²)–H cyanation with NaOCN as the “CN⁺” source.