24748-46-7Relevant articles and documents
Rh(III)-Catalyzed Three-Component Syn-Carboamination of Alkenes Using Arylboronic Acids and Dioxazolones
Lee, Sumin,Rovis, Tomislav
, p. 8585 - 8590 (2021/07/26)
Herein, we report a Rh(III)-catalyzed three-component carboamination of alkenes from readily available aryl boronic acids as a carbon source and dioxazolones as nitrogen electrophiles. This protocol provides facile access to valuable amine products including α-amino acid derivatives in good yield and regioselectivity without the need for a directing functionality. A series of experiments suggest a mechanism in which the Rh(III) catalyst undergoes transmetalation with the aryl boronic acid, followed by turnover limiting alkene migratory insertion into the Rh(III)-aryl bond. Subsequently, fast Rh-nitrene formation provides the syn-carboamination product selectively after reductive elimination and proto-demetalation. Importantly, the protocol provides three-component coupling products in preference to a variety of two-component undesired byproducts.
Carbohydrates as efficient catalysts for the hydration of α-amino nitriles
Chitale, Sampada,Derasp, Joshua S.,Hussain, Bashir,Tanveer, Kashif,Beauchemin, André M.
supporting information, p. 13147 - 13150 (2016/11/09)
Directed hydration of α-amino nitriles was achieved under mild conditions using simple carbohydrates as catalysts exploiting temporary intramolecularity. A broadly applicable procedure using both formaldehyde and NaOH as catalysts efficiently hydrated a variety of primary and secondary susbtrates, and allowed the hydration of enantiopure substrates to proceed without racemization. This work also provides a rare comparison of the catalytic activity of carbohydrates, and shows that the simple aldehydes at the basis of chemical evolution are efficient organocatalysts mimicking the function of hydratase enzymes. Optimal catalytic efficiency was observed with destabilized aldehydes, and with difficult substrates only simple carbohydrates such as formaldehyde and glycolaldehyde proved reliable.
THE PHOTOELIMINATION OF N-NITROSO-N-ACETYL-α-AMINO-ACIDS; A NEW SYNTHESIS OF 1,2,4-OXADIAZOLES
Chow, Yuan L.,Polo, Joel S.
, p. 727 - 734 (2007/10/02)
The excitation of N-nitroso-N-acetyl-α-aminoacids, nitrosopeptide model compounds, under neutral and weakly basic conditions, caused the homolysis of the N-N bond followed by decarboxylation to give hyponitrous acid (HNO) and N-acetylimines which were susceptible to nucleophilic addition.While weak bases caused the carboxylate group to assist intramolecular rearrangement to a small extent, they functioned primarily to provide nucleophilic NO-, which initiated nucleophilic attack leading to the C-nitroso derivatives.These C-nitroso derivatives spontaneously cyclized to 1,2,4-oxadiazoles much more rapidly than tautomerism to the corresponding oximes; the latter oximes failed to cyclize under the basic conditions.
