Research Aimed for the Development of Transition Metal Catalyzed Heterocyclic Synthesis.

本研究旨在利用过渡金属的氧化势，开发新的氮氧杂环合成方法。三年来取得的成果总结如下：(1)在钯（II）催化烯烃胺化反应中，尿素作为特异性的氨基亲核试剂（而非氧亲核试剂），与目前常用的磺胺和氨基甲酸酯相比，具有更高的反应活性和通用性。基于这种方法，可以非常有效地合成以下几类化合物：顺式3-羟基吡咯烷-2-乙酸内酯（吡咯烷烷生物碱的通用合成中间体），双环二氢脲嘧啶，环尿素，γ -和-氨基氨基酸。(2)钯（II）催化3-丁-1-醇羰基化合成α -亚甲基- γ -丁内酯。产率高度依赖于碱的种类。环氧丙烷被证明是最好的碱。(3) Pd（II）催化下，均烯丙醇和均烯丙胺分别与芳基三烷基锡反应合成了2-芳基杂环（如2-芳基四氢呋喃、2-芳基胡椒啶）。

This research was aimed to develop new synthetic methodologies for nitrogen and oxygen heterocycles by the use of the oxidizing potential of transition metals. The results obtained in these 3 years are summarized as follows.(1) For the palladium(II) catalyzed amination of olefins, urea serves as a specific aminonucleophile (not an oxygen nucleophile) and shows the higher reactivity and versatility as compared with sulfonamide and carbamate, commonly utilized hitherto. Based on this methodology, the following classes of compounds can be synthesized very efficiently; cis 3-hydroxypyrrolidine-2-acetic acid lactones (versatile synthetic intermediates for pyrrolitidine alkaloid), bicyclic dihydrouracil, cyclic urea, gamm- and -amino amino acids. (2)alpha-Methylene-gamma-butyrolactones are synthesized by palladium(II) catalyzed carbonylation of 3-butyn-1-ols. The yields are highly dependent on the kind of bases. Propylene oxide proved to be the best base. (3) 2-Arylheterocycles (e.g., 2-aryltetrahydrofurans, 2-Arylpiperidines) are synthesized by the Pd(II)-catalyzed reaction of homoallyl alcohols and homoallylamines, respectively, with aryltrialkyltin.