나트륨 사이아노브로민하이드라이드(나트륨 시아노브롬하이드리드)

Sodium cyanoborohydride is a white or slightly yellow solid powder, It is a versatile reducing agent stable in aqueous solution at pH 7.2. It is a weaker reducing agent as compared to NaBH4. It effectively reduces Schiff bases. NaCNBH4 participates in the reductive methylation for the efficient and selective conversion of the e-amino groups of lysyl residues in proteins to the mono- and dimethyl derivatives.

용도사용 나트륨 시아 노 수소화 붕소는 알데하이드 및 케톤의 환원성 아미 노화 및 아민의 환원성 알킬화 시약으로 일반적으로 사용된다.

개요Sodium cyanoborohydride (NaBH3CN) is a selective reducing agent used for a variety of chemical reductions, including aldehyde, ketones, acetals, epoxides, oximes, enamines, reductive aminations of aldehydes and ketones, and reductive alkylations of amines and hydrazines. The utility of sodium cyanoborohydride as a reducing agent is greatly enhanced by its stability under acid conditions, and its solubility in aprotic solvents. Sodium cyanoborohydride is a milder and more selective reducing agent than sodium borohydride. Sodium cyanoborohydride is a weaker and more-selective reducing agent than sodium borohydride because of the electron-withdrawing effect of the cyano group. It has the further advantage that it is stable in acid to pH = 3 and can be employed to effect reductions in the presence of functional groups that are sensitive to the more-basic conditions of reduction with sodium borohydride. Aldehydes and ketones are unaffected by sodium cyanoborohydride in neutral solution, but they are readily reduced to the corresponding alcohol at pH=3-4 by way of the protonated carbonyl group. By previous exchange of the hydrogens of the borohydride for deuterium or tritium, by reaction with D2O or tritiated water, an efficient and economical route is available for deuteride or tritiide reduction of aldehydes and ketones.

용도Sodium Cyanoborohydride is a commonly used as a reagent in the reductive amination of aldehydes and ketones and in the reductive alkylation of amines. It is also used in the synthesis of a novel phenolate-bridged dilanthanum(III) complex of interest as a model for metalloproteins as well as for its importance in basic and applied chemistry.

Synthesis of Sodium cyanoborohydride(NaBH3CN): NaBH3CN was made by stirring equimolar BH3·THF (~1 M) with NaCN in THF in excellent yield.To a rapidly stirred slurry of sodium borohydride (80.2g, 2.09 mol) in THF (1000mL) in a 2-L flask is added a solution of hydrogen cyanide in THF (294g containing 58.8g of hydrogen cyanide) at 25°C. Evolution of hydrogen occurs slowly during the addition. Following the addition, the reaction mixture is stirred for 1 h at 25°C and then heated at reflux until hydrogen evolution has ceased. Filtration followed by vacuum removal of THF gives white solid sodium cyanoborohydride; yield 120g (91%).