Synthesis of Functionalized Tetrahydropyridines by SnCl
<sub>4</sub>
‐Mediated [4+2] Cycloaddition between Donor–Acceptor Cyclobutanes and Nitriles
作者:David Tong、Jackie Wu、Nathan Bazinski、Donghyun Koo、Naresh Vemula、Brian L. Pagenkopf
DOI:10.1002/chem.201903833
日期:2019.12.2
Cycloadditions of strained carbocycles promoted by Lewis acids are powerful methods to construct heterocyclic frameworks. In fact, the formal [3+2] cycloadditions of donor-acceptor (DA) cyclopropanes with nitriles has seen particular success in synthesis. In this work, we report on the first [4+2] cycloaddition of nitriles with DA cyclobutanes by Lewis acid activation. Tetrahydropyridine derivatives
Synthesis of Hexahydropyridazines by [4 + 2] Cycloaddition of Donor–Acceptor Cyclobutanes and <i>cis</i>-Diazenes
作者:Jackie Wu、Paul Winiarz、Dhwanish Patel、Johanna de Jong、David Tong、Tristan Chidley、Naresh Vemula、Brian L. Pagenkopf
DOI:10.1021/acs.orglett.0c00896
日期:2020.4.17
The GaCl3-catalyzed [4 + 2] cycloaddition between alkoxy- and aryl-activated donor–acceptorcyclobutane diesters and cis-diazene 1a (4-phenyl-1,2,4-triazoline-3,5-dione, PTAD) is disclosed. The reaction provides hexahydropyridazine derivatives as single diastereomers in good to excellent yields in most cases. The structural assignment of the cycloadduct 3b was unambiguously established by single-crystal