| Domino reactions to form carbon-carbon, carbon-nitrigen and carbon-oxygen bonds are versatile tools for the preparation of complex and diverse heterocyclic compounds from readily accessible starting materials in a single operation under mild conditions. It is well known that heterocyclic compounds, such as pyrimidines, oxazines, furans, are the most ubiquitous units and found in many natural products and pharmaceuticals that exhibit remarkable biological activities. And it has been widely investigated and received much more attention because it is widely using in pharmaceutical, food, materials, and agricultural industries. Despite of several methodologies that were developed during the last decade, there is still an intrinsic need for improved routes to the expedient synthesis of more diverse heterocyclic compounds under mild conditions and simple catalytic system.In this thesis, the cyclization reaction involving electron-deficient alkynes for synthesis of pyrimidines, oxazines and furans are mainly studied. The details are summarized as following:(1) Based on the reactive behavior of the substrates, two synthetic methods for polysubstituted pyrimidine derivatives are presented: (i) catalyst-free multicomponent reaction of electron-deficient alkyne, aliphatic amine, and formaldehyde; (ii) Ag(I)-catalyzed synthesis of pyrimidines from electron-deficient alkyne, anilines, and formaldehyde via a domino reaction. Under the optimized conditions, the multicomponent reactions (MCRs) were accomplished with high regioselectivity and excellent yields.(2) We developed two regioselective and stereoselectivity methods from electron-deficient asymmetry alkynes and amines by catalyst-free or Ag(I)-catalyzed, respectively, in our lab. We believe that this reaction proceeds via H-bond intermediate, which contains both a six- and a four-membered ring. This explains the high cis selectivity of the hydroamination process well.(3) An efficient and novel one-pot synthesis of 3,4,5-trisubstituted -3,6-dihydro-2H-1,3-oxazine from alkynoates, anilines and formaldehyde is described. This domino hydroamination/Prins reaction/cyclization/dehydration sequence proceeded smoothly and rapidly owing to the promotion of Br?nsted acids.(4) An efficient synthetic method was developed for the construction of tri- or tetrasubstituted furans from electron-deficient alkynes and 2-yn-1-ol by Ag-catalyzed domino reaction. It is especially noteworthy that 2,3,5-trisubstitued 4-ynyl-furan was formerly obtained in an extremely direct manner without tedious stepwise synthesis. In addition, regio-isomers furans were observed when substituted aryl alkynyl ketones were employed. This methodology represents a highly efficient synthetic route to electron-deficient furans for which catalytic approaches are scarce. The reaction proceeds efficiently under mild conditions with commercially available catalysts and materials.(5) A novel and efficient method for the regiospecific synthesis of polysubstituted furan aldehydes/ketones have been developed via copper(I)-catalyzed rearrangement/ dehydrogenation oxidation/carbene oxidation sequence of 1,5-enynes in-situ formed from alkynols and diethyl but-2-ynedioate under atmospheric pressure. The domino proceeds smoothly under mild conditions with commercially available catalysts, and affords highly functionalized furans in moderate to good yields.(6) We have described a novel and effective nano-Cu2O-catalyzed one-pot domino process for the formation of carbon-carbon and carbon-oxygen bonds to synthesizeα-carbonyl furan. The possible mechanism was performed by forming compound 5 which obtained ethyl 2-diazoacetate (EDA) to trap copper carbine. This protocol is not adding other oxidants, only using air as oxidant under atmospheric pressure. It is especially noteworthy that novel 2,4,5-trisubstituted 2-ynylfuran was formerly formed in an extremely direct manner without tedious stepwise synthesis. In addition, various electronic-deficient alkynes and 2-yl-1-ol underwent this domino process smoothly in moderate to good yields. Furthermore, as all the starting materials are readily available, this method may allow the synthesis of more complexα-carbonyl furans.
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