Study On The Efficient Catalyst And Environmentally-benign Solvent Applied On The Baylis-Hillman Reaction

The Baylis-Hillman reaction, which involves the coupling of Michael acceptor with carbon electrophile (usually aldehydes) under the catalysis of a tertiary amine or phosphine, has drawn increasing attention during the past decades. The resulting multifunctional products allow numerous transformations and have versatile utilities in organic synthesis. However, the reaction typically suffers from sluggish reaction rates and this often limits the range of substrates. To improve the applicability of Baylis-Hillman reaction, a variety of methods including physical as well as chemical attempts have been explored toward enhancement of reaction rate and extension of substrates scope.In this dissertation, Using of Hexamethylenetetramine (HMTA) as an efficient catalyst in the Baylis-Hillman reaction was first studied. HMTA is a cheap alternative catalyst in the Baylis-Hillman between aromatic aldehydes and activated alkenes. In aqueous medium, the use of 0.1 equiv of HMTA proved to be an efficient catalyst for the preparation of the Baylis-Hillman adducts in good to high yields.Next, the scope and feasibility of theN,N,N',N'-Tetramethylethylenediamine (TMEDA) catalyzed aqueous Baylis-Hillman reaction of activated alkenes with various aldehydes were investigated. For arylaldehydes bearing electron-withdrawing-groups, the reaction took place smoothly to afford the desired Baylis-Hillman adducts in good to excellent yields.Encouraged by these useful results, another Lewis base, N-methyl piperidine (NMP), was synthesized and for the first time used as a catalyst for the Baylis-Hillman reaction. In the study of catalytic activity, we found its activity is even superior to that of the most widely used catalyst 1,4-diazabicyclo(2.2.2)octane (DABCO). Indeed, N-methyl piperidine is an excellent catalyst for the Baylis-Hillman reaction.In order to search the better catalyst, we applied the other three...