Sharma Pankaj, Jadhav Prakash D, Skaria Manisha, Liu Rai-Shung
Department of Chemistry, National Tsing-Hua University, Hsinchu, Taiwan, 30013, Republic of China.
Org Biomol Chem. 2017 Nov 15;15(44):9389-9397. doi: 10.1039/c7ob02087b.
This work reports metal-free annulations between one allene, two nitrosoarenes and one electron-deficient alkene to afford bis(isoxazolidine) derivatives stereoselectively. This process involves an initial formation of isoxazolidin-4-imine oxides, followed by their dipolar [3 + 2]-cycloaddition with electron-deficient alkenes. To highlight the utility, the annulations of 5-alleneyl-1-enes with nitrosoarenes were also feasible to afford the desired bis(isoxazolidine) products with excellent stereocontrol. The resulting bis(isoxazolidine) products produced from two systems were reduced with Zn/MeOH to induce reductive N-O cleavages, yielding branched polyaminols stereoselectively.
本工作报道了一种无金属的环化反应，该反应涉及一个联烯、两个亚硝基芳烃和一个缺电子烯烃之间的反应，能立体选择性地生成双（异恶唑烷）衍生物。这个过程首先涉及异恶唑烷-4-亚胺氧化物的形成，随后它们与缺电子烯烃进行偶极[3 + 2]环加成反应。为了突出该反应的实用性，5-联烯基-1-烯烃与亚硝基芳烃的环化反应也可行，能以出色的立体控制得到所需的双（异恶唑烷）产物。由这两个体系生成的双（异恶唑烷）产物用锌/甲醇还原，以引发还原性N-O键断裂，立体选择性地生成支链多氨基醇。
