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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Format: | Thesis |
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Massachusetts Institute of Technology
2024
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Online Access: | https://hdl.handle.net/1721.1/157726 |
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. |
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