The synthesis ofα-amino acid from imines with different carbonyl sources is attractive for both synthetic organic and medicinal chemistry communities.Imines,which were easily available from the corresponding ketones ...The synthesis ofα-amino acid from imines with different carbonyl sources is attractive for both synthetic organic and medicinal chemistry communities.Imines,which were easily available from the corresponding ketones and amines,were employed as one of the most ideal precursors.Traditionally,cyanation and subsequent hydrolysis were required to install the carboxyl group^([1]).In these cases,the toxicity of the cyanation reagents limited its further synthetic applications in organic chemsitry.Besides,metal activation of imine substrates to make the organometallic intermediate and trap CO_(2) to give the desiredα-amino acid were also developed by many groups(Scheme 1A).The utilization of stoiochiometric amounts of metal reagents was required to realize the transformation.Recently,Yu reported a novel photocatalytic reductive carboxylation protocol for synthesis ofα-amino acid from imines with CO_(2)as the carbonyl source^([2]).展开更多
The extraction of L-Arginine with di(2-ethylhexyl)phosphoric acid(D2EHPA) has been studied as functions of equilibrium pH, D2EHPA concentration, L-Arginine equilibrium concentration, NH 4Cl concentration and temperatu...The extraction of L-Arginine with di(2-ethylhexyl)phosphoric acid(D2EHPA) has been studied as functions of equilibrium pH, D2EHPA concentration, L-Arginine equilibrium concentration, NH 4Cl concentration and temperature. The beffer extraction results were obtained in condition of pH=5～7, D2EHPA 0.2～0.4 mol/L, NH 4Cl<0.2 mol/L and low temperature. The equilibrium concentration of L-Arg depends on the saturation extraction capacity.展开更多
文摘The synthesis ofα-amino acid from imines with different carbonyl sources is attractive for both synthetic organic and medicinal chemistry communities.Imines,which were easily available from the corresponding ketones and amines,were employed as one of the most ideal precursors.Traditionally,cyanation and subsequent hydrolysis were required to install the carboxyl group^([1]).In these cases,the toxicity of the cyanation reagents limited its further synthetic applications in organic chemsitry.Besides,metal activation of imine substrates to make the organometallic intermediate and trap CO_(2) to give the desiredα-amino acid were also developed by many groups(Scheme 1A).The utilization of stoiochiometric amounts of metal reagents was required to realize the transformation.Recently,Yu reported a novel photocatalytic reductive carboxylation protocol for synthesis ofα-amino acid from imines with CO_(2)as the carbonyl source^([2]).
文摘The extraction of L-Arginine with di(2-ethylhexyl)phosphoric acid(D2EHPA) has been studied as functions of equilibrium pH, D2EHPA concentration, L-Arginine equilibrium concentration, NH 4Cl concentration and temperature. The beffer extraction results were obtained in condition of pH=5～7, D2EHPA 0.2～0.4 mol/L, NH 4Cl<0.2 mol/L and low temperature. The equilibrium concentration of L-Arg depends on the saturation extraction capacity.
