Zinc Hydride Catalyzed Chemoselective Hydroboration of Isocyanates: Amide Bond Formation and C=O Bond Cleavage
| Autor: | Sharanappa Nembenna, Nabin Sarkar, Rajata Kumar Sahoo |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
010405 organic chemistry Alkene Zinc hydride General Medicine General Chemistry 010402 general chemistry 01 natural sciences Medicinal chemistry Catalysis 0104 chemical sciences chemistry.chemical_compound Hydroboration chemistry Amide Hemiaminal Peptide bond Deoxygenation Bond cleavage |
| Zdroj: | Angewandte Chemie (International ed. in English). 60(21) |
| ISSN: | 1521-3773 |
| Popis: | Herein, a remarkable conjugated bis-guanidinate (CBG) supported zinc hydride, [{LZnH}2 ; L={(ArHN)(ArN)-C=N-C=(NAr)(NHAr); Ar=2,6-Et2 -C6 H3 }] (I) catalyzed partial reduction of heteroallenes via hydroboration is reported. A large number of aryl and alkyl isocyanates, including electron-donating and withdrawing groups, undergo reduction to obtain selectively N-boryl formamide, bis(boryl) hemiaminal and N-boryl methyl amine products. The compound I effectively catalyzes the chemoselective reduction of various isocyanates, in which the construction of the amide bond occurs. Isocyanates undergo a deoxygenation hydroboration reaction, in which the C=O bond cleaves, leading to N-boryl methyl amines. Several functionalities such as nitro, cyano, halide, and alkene groups are well-tolerated. Furthermore, a series of kinetic, control experiments and structurally characterized intermediates suggest that the zinc hydride species are responsible for all reduction steps and breaking the C=O bond. |
| Databáze: | OpenAIRE |
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