Stereoselective Reductive Condensation Reactions

描述（由申请人提供）：在该提案中，描述了一个针对开发新的和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，我们已经开发了催化的对映选择性还原羟醛缩合反应，将市售的硅烷，丙烯酸酯和醛的羟醛加成物。还原性羟醛缩合反应具有优于基于氢化物的羟醛缩合方法和Mukaiyama羟醛缩合方法的优点，因为还原性羟醛缩合反应直接提供甲硅烷基保护的羟醛缩合加合物，在室温下进行，并且直接在市售材料上操作。在拟议的研究中，我们的目标是开发相关的过程，具有类似的操作简单性，但提供的反应产物是不容易通过目前的催化不对称过程。由于非亲氧性后过渡金属催化剂用于这些反应，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（小于0.05摩尔%）下进行，并且不会遭受涉及多氧化底物的催化剂中毒的并发症。

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.