BF3×OEt2-Catalyzed Reaction of Donor-Acceptor Cyclobutanes with [nl]Terminal Alkynes: Single-Step Access to 2,3-Dihydrooxepines
作者:Brian Pagenkopf、Ben Machin
DOI:10.1055/s-0031-1289554
日期:2011.12
In the presence of BF3ËOEt2 cyclobutane-1,1-diesters undergo a reaction with terminal alkynes to quickly access dihydrooxepines.
在 BF3ËOEt2 的存在下,环丁烷-1,1-二酯与末端炔烃发生反应,迅速生成二氢氧杂环庚烷。
The Formal [4+3] Cycloaddition between Donor−Acceptor Cyclobutanes and Nitrones
作者:Andrew C. Stevens、Cory Palmer、Brian L. Pagenkopf
DOI:10.1021/ol200220d
日期:2011.3.18
The formal [4+3] cycloaddition of 2-alkoxy-1,1-dicarboxylate activated donor -acceptor cyclobutanes with nitrones Is disclosed. The reaction forms structurally unique oxazepines in moderate to high yield with a wide scope of nitrones. In most cases either a diastereomeric mixture or a single diastereomer may be formed, depending on the reaction conditions.
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