Studies On The Synthesis Of Functionalized Unsaturated Carbonyl Compounds And Catalytic Asymmetric Diels-Alder Reaction

Asymmetric Diels-Alder reaction has widely been paid attentions to the field oforganic synthesis as one of the key techniques in green chemistry. Due to the highenantioselectivity of the cycloadduct, it has been widely applied to synthesis ofcomplexes, medicines, pesticides, food additives, spice and natural compounds. Inthis dissertation, the Diels-Alder reaction, particularly catalyzed by chiral catalyst,was investigated.1. Studies on the synthetic method of functionalized unsaturated carbonylcompounds. Firstly, one-pot method of preparing N-acyl pyrrolidone derivatives andlactams were developed by the nucleophilic substitution of unsaturated acid withimides and laetams using triphosgene in ionic liquids, a green chemistry procedure tomeet the demand of green chemistry. Secondly, the selective bromination ofunsaturated ketone using bromination reagent was performed and correspondingbrominated methyl ketone was obtained in high yield. The method for preparation of1-phenylsulfonyl-3-alken-2-ones was improved. Thirdly, a novel method ofpreparingα,β-unsaturated esters were developed. Under the catalysis of amino acid inionic liquids,α,β-unsaturated esters had been prepared by using ethyl 3-oxobutanoatewith aldehyde.2. Studies on the asymmetric Diels-Alder reaction of functionalized unsaturatedcarbonyl compounds. Firstly, various aeylopyrrolidone derivatives ofα,β-unsaturatedcarboxylic acids react smoothly with dienes promoted by a catalytic amount of ZnI₂ in CH₂Cl₂. It was accelerated by using ultrasonic and microwave in ionic liquids and theyield and stereoselectivity of cycloadduct were raised. After investigating variousLewis acids, we found that FeCl₃·6H₂O was an excellent catalyst and the cycloadductsof N-acyl lactams with dienes were obtained in high yield and stereoselectivityunder solvent-free conditions at room temperature. Secondly, the absoluteconfiguration of the cycloadduct was determined in the asymmetric Diels-Alderreaction of （E）-1-（phenylsulfonyl）pent-3-en-2-one with cyclopentadiene catalyzed bychiral titanium reagent, and mechanism of this reaction was presented based onanalytical result of crystal structure. Thirdly, the Diels-Alder reaction ofα,β-unsaturated esters was discussed under solvent-free conditions at room temperatureand seven new cycloadducts were obtained.3. A chiral imidazolidinone with indole group as catalyst was synthesized andasymmetric Diels-Alder reaction ofα,β-unsaturated aldehyde with dienes wasdiscussed at first time. Corresponding cycloadducts were obtained in high yield andthe optical purity was up to 95%e.e.. The probable transition station was proposedaccording to the absolute configuration of the cycloadducts.