Stereoselective Reductive Condensation Reactions

描述(由申请人提供)：在本提案中，描述了一项旨在开发新的和具有合成价值的立体选择性催化还原缩合反应的计划。在我们的初步研究中，我们开发了催化的对映选择性还原Aldol反应，它将商业上可用的硅烷、丙烯酸酯和醛转化为Aldol加合物。与助剂和Mukaiyama Aldol工艺相比，还原Aldol反应具有优势，因为还原Aldol反应直接提供硅基保护的Aldol加合物，在室温下进行，并直接使用商业可获得的材料进行操作。在拟议的研究中，我们的目标是开发具有类似操作简单性的相关工艺，但提供当前催化不对称工艺难以获得的反应产物。由于这些反应使用的是非亲氧的后过渡金属催化剂，我们怀疑我们开发的还原缩合过程可以在极低的催化剂负载量(低于0.05摩尔百分比)下进行，并且不会出现催化剂被多氧底物中毒的并发症。

DESCRIPTION (provided by applicant): In this proposal, a program directed towards the development of novel and synthetically valuable stereoselective catalytic reductive condensations reactions is described. In our initial studies we have developed the catalytic enantioselective reductive aldol reaction which converts commercially available silanes, acrylates and aldehydes to aldol adducts. The reductive aldol reaction holds an advantage over auxiliary-based and Mukaiyama aldol processes in that the reductive aldol reaction directly provides silyl protected aldol adducts, proceeds at room temperature and operates directly on commercially available materials. In the proposed research, we aim to develop related processes that have similar operational simplicity but which afford reaction products which are not readily available by current catalytic asymmetric processes. Since non-oxophilic late transition metal catalysts are used for these reactions, we suspect that the reductive condensation processes we develop may proceed at exceptionally low catalyst loading (less than 0.05 mol percent) and not suffer from complications involving catalyst poisoning by polyoxygenated substrates.