CATALYTIC METHODS FOR STEREOSELECTIVE SYNTHESIS

有了这个奖项，化学合成（SYN）计划正在资助俄亥俄州州立大学化学系的T. V. RajanBabu教授探索合成中的催化方法。SYN程序发现特别值得注意的是有效的Ni介导的氢化乙烯基化转化，以及在最后一个循环中开发的令人印象深刻的区域发散Y-salen介导的氮丙啶开放化学。 在下一个周期的研究计划的主要特点包括有效的立体选择性加氢乙烯基化反应的机制的调查和前所未有的不对称甲硅烷基（硼基）锡烷基化二炔环化，将得到轴向手性环状二烯的发展。在大多数成环反应中，即使是在高催化性和选择性的反应中，官能团的数量通常在从不饱和起始材料到产物的过程中耗尽。 在上述由各种X-Y试剂（X，Y = [R3 Si]，[R3 Sn]，[R2 B]）介导的二炔，烯炔，丙二烯炔和丙二烯-醛的金属催化环化中，反应产物中官能团的数目净增加。 此外，在α，ω-二炔环化的情况下，产物（ZZ）-1，2-双-亚烷基是轴向手性的，并且这种手性转移到新形成的环周围的手性中心预计将为环化反应中的立体控制增加新的维度。 这些催化过程是RajanBabu研究小组的一个潜在的绿色化学主题和相关工作的一部分。 这一主题延续到本科有机教学实验室，其中一个项目，涉及水，不对称生物催化还原不对称酮已被引入。 这样的实验室经验使大量的本科生接触到现代有机合成的几个方面（例如，手性、不对称催化、绿色化学、结构-活性关系、手性固定相色谱分离）。

With this award, the Chemical Synthesis (SYN) Program is funding Professor T.V. RajanBabu of the Department of Chemistry at Ohio State University to explore catalytic methods in synthesis. The SYN Program finds particularly notable both the efficient Ni-mediated hydrovinylation transformation, and the impressive regiodivergent Y-salen-mediated aziridine opening chemistry developed in the last cycle. Key features of the research plan in the next cycle include investigation of the mechanism of the efficient stereoselective hydrovinylation reaction and development of an unprecedented asymmetric silyl(boryl)stannylation-diyne cyclization that would give axial chiral cyclic dienes. In most ring-forming reactions, even among highly catalytic and selective ones, the number of functional groups is often depleted in going from an unsaturated starting material to a product. In the aforementioned metal-catalyzed cyclization of diynes, enynes, allenynes and allene-aldehydes mediated by various X-Y reagents (X, Y = [R3Si], [R3Sn], [R2B]), there is a net increase in the number of functional groups in the product of the reaction. Moreover, in the case of the alpha,omega-diyne cyclization, the product (ZZ)-1,2-bis-alkylidene is axially chiral, and transfer of such chirality to centers of chirality around the newly formed ring is projected to add a new dimension to stereocontrol in cyclization reactions. These catalytic processes are part of an underlying green chemistry theme of this and related work in the RajanBabu research group. This theme carries over into the undergraduate organic teaching laboratory in which a project involving an aqueous, asymmetric biocatalytic reduction of unsymmetrical ketones has been introduced. Such a laboratory experience exposes a large undergraduate population to several aspects of modern organic synthesis (e.g., chirality, asymmetric catalysis, green chemistry, structure-activity relationships, separations by chiral stationary phase chromatography).