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
Formal [4 + 2] Cycloaddition of Donor−Acceptor Cyclobutanes and Aldehydes: Stereoselective Access to Substituted Tetrahydropyrans
作者:Andrew T. Parsons、Jeffrey S. Johnson
DOI:10.1021/ja906755e
日期:2009.10.14
diastereoselective synthesis of 2,6-cis-disubstituted tetrahydropyrans (THPs) via Lewis acid-catalyzed formal [4 + 2] cycloaddition of donor-acceptor cyclobutanes and aldehydes has been developed. THP products are formed in up to 96% yield and 99:1 diastereoselectivity. Aromatic, cinnamyl, and aliphatic aldehydes are competent dipolarophiles in this system. This methodology was extended to a [[2 + 2] + 2] cycloaddition