Reaching New Horizons in Iminyl Radical Chemistry via Microwave Irradiation

通过微波辐射实现亚氨基自由基化学的新视野

基本信息

批准号：
1856530
负责人：
Steven Castle
金额：
$ 49.64万
依托单位：
Brigham Young University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2023-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1856530&HistoricalAwards=false
关键词：
Reaching New Horizons Iminyl Radical

项目摘要

With this award, the Chemical Synthesis Program of the NSF Division of Chemistry is supporting the research of Professor Steven L. Castle of Brigham Young University. Professor Castle is developing new methods for synthesizing organic molecules that are facilitated by microwave energy rather than by catalysts or reagents that are often toxic, hazardous, or expensive. In comparison to traditional organic synthesis techniques, these methods are providing safer, more sustainable, and more efficient routes to compounds that have potential application as pharmaceuticals. A key innovation is the use of microwaves to trigger cascade processes that convert simple precursors into complex and useful compounds by enabling a sequence of chemical transformations to occur in a controlled fashion. Professor Castle and his students are impacting STEM education by creating lesson plans that will assist high school chemistry teachers with incorporating organic chemistry into their courses. These plans are designed to inspire high school students to pursue STEM careers by exposing them to the exciting world of organic chemistry and teaching them about the positive impact that chemistry has on human health and quality of life.Professor Castle and his co-workers employ O-aryl oxime ethers as precursors of iminyl radicals. Upon irradiation with microwaves, these species undergo direct homolysis of the O-N bond. The resulting iminyl radicals are then transformed by either cyclization or hydrogen atom abstraction (i.e., C-H activation). In both cases, a radical intermediate is formed and subsequently trapped by a reagent that forges a new C-C, C-N, C-O, C-S, or C-X bond. By generating iminyl radicals under nonreducing conditions in the absence of metal catalysts or redox cycles, these reactions permit a wide range of functionalized radical traps to be used. Additionally, the cyclizations are stereoselective and can be incorporated into cascade processes. The utility of these microwave-based methods is being demonstrated through the efficient construction of a member of the securinega family of alkaloids. The student participants in this project are receiving training in experimental techniques, troubleshooting, communication, and critical thinking that will enable them to pursue careers in chemistry or other STEM fields.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

凭借该奖项，美国国家科学基金会化学部的化学合成项目正在支持杨百翰大学史蒂文·L·卡斯尔教授的研究。 Castle 教授正在开发合成有机分子的新方法，这些方法是通过微波能量而不是通常有毒、有害或昂贵的催化剂或试剂来促进的。与传统的有机合成技术相比，这些方法为具有药物潜在应用的化合物提供了更安全、更可持续和更有效的途径。一项关键的创新是使用微波触发级联过程，通过以受控方式发生一系列化学转化，将简单的前体转化为复杂且有用的化合物。 Castle 教授和他的学生正在制定课程计划，帮助高中化学教师将有机化学纳入课程中，从而影响 STEM 教育。这些计划旨在激励高中生追求 STEM 职业，让他们接触令人兴奋的有机化学世界，并教导他们化学对人类健康和生活质量的积极影响。Castle 教授和他的同事雇用了 O -芳基肟醚作为亚氨基自由基的前体。在微波照射下，这些物质的 O-N 键发生直接均裂。然后通过环化或夺取氢原子（即 C-H 活化）来转化所得的亚氨基自由基。在这两种情况下，都会形成自由基中间体，随后被试剂捕获，形成新的 C-C、C-N、C-O、C-S 或 C-X 键。通过在不存在金属催化剂或氧化还原循环的情况下在非还原条件下产生亚氨基自由基，这些反应允许使用各种官能化自由基捕集器。此外，环化是立体选择性的，可以纳入级联过程。这些基于微波的方法的实用性正在通过生物碱家族成员的有效构建得到证明。该项目的学生参与者正在接受实验技术、故障排除、沟通和批判性思维方面的培训，这将使他们能够在化学或其他 STEM 领域追求职业生涯。该奖项反映了 NSF 的法定使命，并通过评估被认为值得支持基金会的智力价值和更广泛的影响审查标准。