Enantioselective trapping of palladium-stabilized oxo-1,4-dipoles with photochemically generated ketenes

• 作者: Miao-Miao Li Bao-Le Qu Yu-Qing Xiao Wen-Jing Xiao Liang-Qiu Lu
• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2021,（17）
• 所属期刊栏目: SHORT COMMUNICATIONS
• 页码范围: 1719-1722
• 页数: 4页
• 语种: 英文

摘要

The development of efficient strategies for constructing oxo-heterocyclic architectures is a highly significant topic in modern synthetic chemistry,due to their wide existence in plenty of natural products,medical and agricultural chemicals[1-4].It is well-known that selectivity,especially stereoselectivity,still lags largely behind many precedent endeavors,which stimulates the synthetic community to search for more efficient and selective methods for oxo-heterocycle synthesis.In this context,2-alkylidenetrimethylene carbonates(ADTMCs)that were first reported by Tsuji and co-workers[5]in 1984 were applied to the Pd-catalyzed cycloaddition with isocyanates by Hayashi and co-workers[6]in 2011(Fig.1a).While,in this work the selectiv-ity between 5-or 6-membered cyclic products relies on the alkyl or aryl substituents on the nitrogen atom.In 2019,Liu,Zhang and co-workers[7]applied ADTMCs to the Pd-catalyzed[4+2]cycloaddition with[60]fullerene intelligently,affording[60]fullerene-fused pyrans in good yields.In 2020,Shibata and co-workers[8]disclosed a Pd-catalyzed[5+4]cycloaddition of ADTMCs with isatins and their analogs to access 9-membered heterocycles.Despite these impressive advances,usually only racemic oxo-heterocycles can be prepared and enantio-control still remains a challenge for ADTMCs-involved cycloaddition chemistry[9].