Developments of Novel Synthetic Reactions under High Pressure Conditions

(A)树脂酸的Diels-Alder反应：在高压条件下建立了顺丁烯二酸甲酯与顺丁烯二酸酐和N-苯基马来酰亚胺的Diels-Alder反应。(B)AI-77-B的合成研究：研究了用高压方法在AI-77-B的羟基氨基酸部分与二氢异香豆素之间构筑酰胺键。因此，从D-核糖制备的N-Boc内酰胺衍生物作为一个模型反应，可以在10kbar的压力下有效地与环己胺缩合，而不需要任何催化。(C)环氧化物与甘氨酸酯的氨解反应：在高压条件下，环氧化物与甘氨酸酯的非催化氨解反应是有效的。在这项研究中，我们发现硅胶是这类环氧化物开环反应的强有力的固体酸催化剂。(D)环氧化物与氮杂环的反应：环氧化物与吲哚、吡咯和吡唑等氮杂环的反应是…进行的在高压促进或硅胶催化条件下更有规律。新的手性配体的合成设计：手性环氧化物与吡唑类化合物的高压反应提供了合成手性二唑类配体的新方法。这些配体被成功地应用于苯甲醛和二乙基锌的不对称烷基化反应。(F)迪奥霉素A2的合成：以吲哚为关键步骤，通过高压促进的环氧化物开环反应进行了一种新的短时间合成迪奥霉素A2的方法。(G)环氧化物到相应的卤代醇的转化：在干燥介质中，通过硅胶负载的卤化锂处理，各种环氧化物可以有效地转化为相应的卤代醇。(H)高压条件下硅胶的官能化：作为高压化学的最后一个项目，我们开发了一种新的硅胶与手性物质官能化的方法，并证明了它在高效液相色谱分析中的应用。较少

(a) Diels-Alder Reaction of Resin Acids : Novel Diels-Alder reaction of methyl palustrate with maleic anhydride and N-phenylmaleimide has been established under high pressure conditions.(b) Synthetic Study of AI-77-B : High pressure approach to construct the amide bond between a dihydroisocoumarin and a hydroxyamino acid part of AI-77-B has been investigated. Thus, as a model reaction, the N-Boc lactam derivative prepared from D-ribose was efficiently condensed with cyclohexylamine at 10 kbar pressure without using any catalysis.(c) Aminolysis of Epoxides with Glycine Esters : Uncatalyzed aminolysis of epoxides with glycine esters has been efficiently performed under high pressure conditions. In connection with this study, we found that silica gel acted as a powerful solid acid catalyst for this type of epoxide opening reaction.(d) Reaction of Epoxides with Nitrogen Heterocycles : The reaction of epoxides with nitrogen heterocycles such as indoles, pyrroles, and pyrazoles has been perf … More ormed under high pressure-promoted or silica gel-catalyzed conditions. The stereochemical feature for an epoxide opening reaction with indole has been proposed as having a concerted S_N2 mechanism.(e) Synthetic Design of Novel Chiral Ligands : High pressure reaction of chiral epoxides with pyrazoles provided novel procedure to obtain chiral diazole ligands. These ligands were successfully applied for an enantioselective alkylation of benzaldehyde with diethylzinc.(f) Synthesis of Diolmycin A2 : A new short synthesis of diolmycin A2 has been performed by using high pressure-promoted epoxide opening reaction with indole as a key step.(g) Transformation of epoxides to the Corresponding Halohydrins : A variety of epoxides have been efficiently converted into the corresponding halohydrins by treatment with silica gel-supported lithium halides in dry media.(h) Functionalization of Silica Gel under High Pressure Conditions : As a final project to use high pressurt chemistry, a new method to functionalize silica gel with chiral substances has been developed and its utility for HPLC analysis has been also demonstrated. Less