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New Guanidine Chemistry

新胍化学

基本信息

批准号：
14370717
负责人：
ISHIKAWA Tsutomu
金额：
$ 6.78万
依托单位：
Chiba University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

Guanidinium ylide-paiticipated asymmetric aziridination was precisely examined. Thus, the formation of the ylides was confirmed by NMR spectroscopy. Acid anhydrides, like silica gel, could contribute to the fragmentation of adduct intermediates from guanidinium ylides and aryl aldehydes to aziridine and urea products. Examination of reaction using a variety of p-substituted benzaldehydes allowed us to categorize the aziridination to two groups dependent upon the substituents, causing different reaction rate and stereochemistry of aziridine products. The enatio-and diastereoselectivities could be reasonably explained by Hammett analysis.This aziridine synthesis is sensitive to the steric bulikiness of the stalling guanidinium salts and, thus, low reactivity was observed on substituted guanidinium salts. α,β-Unsaturated aldehydes, like aryl aldehydes, could serve as aldehyde substrates to afford aziridines with high enantioselectivity. Straight-forward aziridine formation was observed when tertiary guanidine are subjected to not only the reaction in the presence of alkylating agents but also the reaction with styrene oxides.On the other hand in the course of exploiting the potential functionality of chiral guanidines guanidine-catalyzed asymmetric chromanone construction was examined by application of intramolecular Michael reaction expected asymmetric induction was observed. General preparation method for the polymer-supported guanidines as potential environment-directed catalysts was basically established. Atom-economical synthesis of biologically active N-containing compounds using chiral aziridines as building blocks was developed. Thus, ring-opening reactions of aziridine skeletons were examined either under reductive conditions or in the presence of nucleophiles. As a example enantioselective total synthesis of D-erythro-sphingosine was achieved. Furthermore, chemical modification of aziridines was attempted for their ring-expansion to β-lactam skeletons

精确检测了胍叶立德参与的不对称氮丙啶化反应。因此，通过NMR光谱证实了叶立德的形成。酸酐，如硅胶，可以促进从胍叶立德和芳基醛到氮丙啶和尿素产物的加合物中间体的裂解。使用各种对位取代的苯甲醛进行的反应检查使我们能够根据取代基将氮丙啶化分为两组，从而导致不同的反应速率和氮丙啶产物的立体化学。对映选择性和非对映选择性可以通过哈米特分析合理地解释。这种氮丙啶合成对失速胍盐的空间体积敏感，因此，在取代的胍盐上观察到低反应性。 α,β-不饱和醛，如芳基醛，可以作为醛底物来提供具有高对映选择性的氮丙啶。当叔胍不仅在烷基化剂存在下进行反应，而且与氧化苯乙烯反应时，观察到直接的氮丙啶形成。另一方面，在开发手性胍的潜在功能的过程中，通过应用分子内迈克尔反应检查了胍催化的不对称色满酮结构，观察到了预期的不对称诱导。基本建立了聚合物负载胍作为潜在环境导向催化剂的通用制备方法。开发了使用手性氮丙啶作为结构单元的具有生物活性的含氮化合物的原子经济合成方法。因此，在还原条件下或在亲核试剂存在下检查氮丙啶骨架的开环反应。作为一个例子，实现了 D-赤型鞘氨醇的对映选择性全合成。此外，还尝试对氮丙啶进行化学修饰，使其扩环为 β-内酰胺骨架