| As an important part of organic reactions,solvent-free reaction has become one of the hot-spot recently for avoiding the use of organic solvents which is consistent with the “Green Chemistry”.Ball milling,a newly developed method to promote solvent-free reaction,has been successfully applid in many kinds of organic synthesis reactions.Chapter 1 briefly presents origin and development of the mechanochemistry,and reviews the organic reactions of the C-C formation and organic asymmetric reactions under ball milling conditions.In Chapter 2,the oxidative Mannich reaction between N-aryl tetrahydroisoquinolines and N-carbonyl tetrahydroisoquinolines with ketones in the ball millling was investigated.The effects of milling frequency,time,grinding aids,substrates?s ratio,oxidant on the oxidative Mancih reaction were studied.With the use of DDQ,a safe,stable and easy to store oxidant,desired products were obtain within short reaction time in moderate to good yields.These reactions requiring no toxic organic solvents and provide a fast,convenient,environment friendly method for the synthesis of tetrahydroisoquinoline derivatives which having potential biological activity.In Chapter 3,mechanically promoted aza-henry reactions applied to the preparation of Praziquantel were investigated here for the first time.Dihydroisoquinoline,nitromethane,chloroacetyl chloride was used as substrates to undergo aza-henry reaction in ball milling,and then through catalytic hydrogenation,acylation and cyclization to finally give Praziquantel.The influence of milling frequency,substrates?s ratio and the base on mechanically promoted aza-henry reaction were investigated detailedly.Compared to traditional preparations of Praziquantel,this synthetic route is short,fast and efficient.To obtain(R)-Praziquantel,the method of asymmetry aza-henry reaction under ball milling was investigated by using organic chiral catalyst. |
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