| Nitrile compounds play an irreplaceable role in many fields such as chemical industry,pharmacy and natural compounds and so on.Whether they are natural nitrile compounds with high medicinal value,copolymer or as an intermediate who can transfer to many other functional groups in organic synthesis.All reflect the significance of studying synthetic methods of the nitrile compounds.In the study of electrophilic α-cyanation,there are few reports on the direct α-cyanation of β-keto amide,and even no report mentioned the direct α-cyanation of acyclic β-keto ester or amide.Therefore,it is very necessary to explore and enrich the directα-cyanation of these two kinds of substrates.9 kinds ofβ-keto amides bearing five-membered ring and 4 kinds ofβ-keto amides bearing six-membered ring were synthesized.All the above 13 substrates can be converted into corresponding racemate products by the direct electrophilicα-cyanation.All racemic compounds were verified by NMR(1H NMR and 13C NMR)IR,MP and high resolution mass spectrometry.These racemates were resoluted on chiral HPLC analysis which is of great importance for the asymmetric version reaction.In addition,the α-cyanation of acyclic β-keto ester was explored in two ways.One,with ethyl benzoylacetate as the substrate,6 kinds of cationic cyano reagents were tested while other reaction conditions such as temperature,base and Lewis acid were also screened.Unfortunately,it failed to obtain the target product.The other,with TMSCN as the anionic cyano reagent,TBAI as catalyst,TBHP as the oxidant β-keto ester was taken into consideration of α-cyanation affording no desired product but some un-elucidated side reactions. |
