A highly efficient and green process for the synthesis ofα-aminophosphonates has been developed through a one-pot three-component reaction of various aldehydes,amines,and phosphine oxide in the presence of indium com...A highly efficient and green process for the synthesis ofα-aminophosphonates has been developed through a one-pot three-component reaction of various aldehydes,amines,and phosphine oxide in the presence of indium complexes as competent catalysts under neat conditions at room temperature.The indium complexes[κ^(2)-{RNC(Me)[double bond,length as m-dash]CHC(Me)[double bond,length as m-dash]O}_(2)InCl](R=2,6-diisopropylphenyl(Dipp),2a;2,4,6-trimethylphenyl(Mes),2b),and[κ^(2)-{DippNC(Me)[double bond,length as m-dash]CHC(Me)[double bond,length as m-dash]O}_(2)In(OTf)][(OTf=CF_(3)SO_(3)^(−),3a)were synthesised by the reaction of protic ligandβ-ketoimine with an equivalent amount of lithium hexamethyldisilazide followed by the addition of indium trichloride in toluene.The solid-state structures of complexes 2a,2b,and 3a are established by single-crystal X-ray diffraction analysis.In all the indium complexes,the indium ion is five-fold coordinated and adopts a distorted trigonal bipyramidal geometry around it.The catalytic method offers an efficient approach with a broad range ofα-aminophosphine oxide derivatives in excellent yields with good functional group tolerance.Density functional theory based mechanistic studies demonstrate energetically affordable pathways at room temperature for the indium catalysed aminophosphorylation of benzaldehyde,phenylamine,and diphenylphosphine oxide.The rate-limiting step deduced in this aminophosphorylation is the initial step in which phenylamine reacts with indium-coordinated benzaldehyde to build a C-N bond with a concomitant transfer of a proton from phenylamine to benzaldehyde.展开更多
基金supported by the Science and Engineering Research Board(SERB),Government of India,under project no.(EMR/2016/005150)the Faculty Initiation Grant(FIG–100810)and computational facilities provided by IIT Roorkee.
文摘A highly efficient and green process for the synthesis ofα-aminophosphonates has been developed through a one-pot three-component reaction of various aldehydes,amines,and phosphine oxide in the presence of indium complexes as competent catalysts under neat conditions at room temperature.The indium complexes[κ^(2)-{RNC(Me)[double bond,length as m-dash]CHC(Me)[double bond,length as m-dash]O}_(2)InCl](R=2,6-diisopropylphenyl(Dipp),2a;2,4,6-trimethylphenyl(Mes),2b),and[κ^(2)-{DippNC(Me)[double bond,length as m-dash]CHC(Me)[double bond,length as m-dash]O}_(2)In(OTf)][(OTf=CF_(3)SO_(3)^(−),3a)were synthesised by the reaction of protic ligandβ-ketoimine with an equivalent amount of lithium hexamethyldisilazide followed by the addition of indium trichloride in toluene.The solid-state structures of complexes 2a,2b,and 3a are established by single-crystal X-ray diffraction analysis.In all the indium complexes,the indium ion is five-fold coordinated and adopts a distorted trigonal bipyramidal geometry around it.The catalytic method offers an efficient approach with a broad range ofα-aminophosphine oxide derivatives in excellent yields with good functional group tolerance.Density functional theory based mechanistic studies demonstrate energetically affordable pathways at room temperature for the indium catalysed aminophosphorylation of benzaldehyde,phenylamine,and diphenylphosphine oxide.The rate-limiting step deduced in this aminophosphorylation is the initial step in which phenylamine reacts with indium-coordinated benzaldehyde to build a C-N bond with a concomitant transfer of a proton from phenylamine to benzaldehyde.
