| Research Abstract |
Novel type of indium reagents could be developed and were applied to organic synthesis. Following reactions were performed. (1)Generation of indium hydride and its application to the reduction of various functionalities. (2)Novel Lewis acid system generated by indium chloride and hydrosilanes.
As a example of method 1, dichloroindium chloride(Cl_2InH)could be generated by transmetallation between tributyltin hydride and InCl_3. Indoium hydride have scarcely been used in organic synthesis because of difficulty to their generations. This is the first application of injium hydride in organic synthesis. The generated Cl_2InH could reduce various functional group such as akdehydes, ketones acid chloride and alkyl hakides. In particular, the reduction of acid halide gave an aldehyd as a sole product. In place of indium hydrie, allylic indium also could be generated, which react with acid chloride to give homoallyl ketones selectively. In these reaction, phosphine oxide played an important role as a ligand to control the reactvity of indium reagent. Indium hydride could reduce alkyl halide effectively where the reaction involved radical process. In particular, room temperature radical reacttion could be attained. In addition the use of indium hydride underwent radical cyclization reactions.
Secondary, as a example of method 2, indium chloride acted as a novel Lewis acid by the combination with hydrosilanes. Thus reductive Friedel-Crafts reaction between aromatis and carbonyl compounds were performed. The In-Si system enable the deoxygenation of ketones to give alkanes. This method could be enlarged to introduce various functionalities to ketones in deoxygenatice manner. Moreover, deoxygenarion of alcohols could be established.where various alcohols including aromatic and aliphatic ones could be applicable.
|
