Organocatalytic Tandem Reactions With Morita-Baylis-Hillman Adducts

Organocatalytic tandem reaction is a compelling field of organic synthesisbecause this methodology is able to maximize the utilization of the starting material,avoid the separation of the intermediate and reduce the overall cost of the reaction inthe construction of complex molecules. It is an economical and environmentalfriendly new reaction method. We designed several organocatalytic tandem reactionsbased on Morita-Baylis-Hillman reaction adducts, during which a series of highlyfunctional, oxygen-containing heterocyclic compounds were built. The main contentis as follows：1. We developed a tandem Strecker-allylic-alkylation reaction, and synthesizeda series of densely functionalized nitriles which can be easily converted into α-methylene-γ-butyrolactams. We also accomplished the synthesis of α-methylene-γ-butyrolactams with aldehydes, amines and other substrates as starting materials inone pot fashion.2. We studied in depth on the factors which might affect the regioselectivity of thetandem Strecker-allylic-alkylation reaction, including solvents, N-substitutedgroups and other influencing factors. Commence with Morita-Baylis-Hillman reactionadducts, we regioselectively constructed both α-methylene-β-and γ-amino acidderivatives in high efficiency. This greatly enriched the application of our Strecker-allylic-alkylation reaction in organic synthesis and also helps us to better understandthis tandem reaction.3. We developed an efficient asymmetric catalytic tandem allylic-substituted-intramolecular Diels-Alder reaction of furan and synthesized a series ofoxa-norbornene compounds. We systematically studied the factors which arehypothesized to affect the rate, diastereoselectivity and enantioselectivity of the reaction including chiral catalysts， solvents and N-substituted groups. Idealexperimental conditions were established. Our method was applicable to a large scopeof substrates. The oxa-norbornene skeletons constructed in the reaction are potentialbuilding blocks in the synthesis of various natural products.