Asymmetric N-H/N-alkyl olefin azirdinations and ring-opening transformations

 描述（由申请人提供）：氮杂环丙烷是环氧化物的三元和同等高度紧张的氮类似物，由于其在无数区域和立体选择性转化中的多功能性，是合成结构复杂分子的重要合成中间体。氮丙啶结构基序，主要是N-H和较小程度的N-烷基，也出现在天然产物中，其表现出有效的抗生素，免疫调节和抗癌特性。目前的直接烯烃氮丙啶化方法依赖于取代的氮烯向烯烃的C=C键的转移或取代的卡宾向亚胺的C=N键的转移。通常，结果是氮丙啶带有强吸电子N-保护基团，其去除可导致氮丙啶的破坏。此外，这些N-保护的氮烯的高反应性可引起非生产性烯丙基C-H胺化以及立体特异性的损失。该建议有两个主要目标：（a）开发直接的、立体特异性的和实用的无保护的（即，N-H，N-烷基）氮丙啶和（B）使用均相过渡金属催化的烯烃的双官能化，得到邻位官能化的胺。这些目标将在三个具体目标中发展：（1）开发和优化烯烃的直接、催化的对映选择性N-H/N-烷基氮丙啶化反应;（2）开发过渡金属催化的直接氢-/碳-/杂原子-氨基烯烃双官能化反应，得到未保护的氨基醇、叠氮基胺以及伯、仲和叔胺;（3）设计和合成一类新型N-H/N-烷基转移剂（即，胺化剂），其将在直接烯烃N-H/N-烷基氮丙啶化和氢-/碳-/杂原子-氨基烯烃双官能化中提供前所未有的化学和立体选择性范围。

 DESCRIPTION (provided by applicant): Aziridines, the three-membered and equally highly-strained nitrogen analogues of epoxides, are important synthetic intermediates en route to structurally complex molecules due to their versatility in myriad regio- and stereoselective transformations. The aziridine structural motif, predominantly N-H and to a lesser extent N-alkyl, also appears in natural products which exhibit potent antibiotic, immunomodulatory and anticancer properties. Current direct olefin aziridination methods rely either on the transfer of substituted nitrenes to the C=C bond of olefins or the transfer of substituted carbenes to the C=N bond of imines. Normally, the result is an aziridine bearing a strongly electron-withdrawing N-protecting group whose removal can result in destruction of the aziridine. In addition, the high reactivity of these N-protected nitrenes can give rise to non-productive allylic C-H amination as well as the loss of stereospecificity. This proposal has two main goals: (a) the development of direct, stereospecific and practical syntheses of unprotected (i.e., N-H, N-alkyl) aziridines and (b) bis-functionalization of olefins leading to vicinally functionalized amines using homogeneous transition metal catalysis. These objectives will be developed in three specific aims: (1) Development and optimization of the direct, catalytic enantioselective N-H/N-alkyl aziridination of olefins; (2) Development of transition-metal-catalyzed direct hydro-/carbo-/heteroatom-amino olefin difunctionalizations, affording unprotected amino-alcohols, azido-amines as well as primary, secondary and tertiary amines; (3) Design and synthesis of a family of novel N-H/N-alkyl transfer agents (i.e., aminating agents) that will provide an unprecedented range of chemo- and stereo-selectivities in both direct olefin N-H/N-alkyl aziridinations and hydro-/carbo-/heteroatom-amino olefin difunctionalizations.