Phosphine‐Catalyzed Chemoselective [4+3] Cycloaddition of Alminine Esters and β′‐acetoxy Allenoates for Divergent Synthesis of Azepines. Issue 3 (3rd December 2019)

• Record Type: Journal Article
• Authors: Dai, Zonghao; Zhu, Jin; Wang, Jiahua; Su, Wenbo; Yang, Fulai; Zhou, Qingfa
• Is Part Of: Advanced synthesis & catalysis. Volume 362:Issue 3(2020)
• Page Start: 545
• Page End: 551
• Publication Date: 2019-12-03
• Subjects: phosphine -- azepines -- cycloaddition -- aldimine esters -- allenoates; Catalysis -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Chemistry -- Periodicals; Chemistry, Technical -- Periodicals; Chemistry -- Periodicals; Catalysis -- Periodicals; Technology, Pharmaceutical -- Periodicals; 547.2
• DOI: 10.1002/adsc.201901132
• Languages: English
• ISSNs: 1615-4150

Abstract

Abstract: Abstract Text. A general method for the synthesis of structural diversity and complexity of azepines from aldimine esters and β′‐acetoxy allenoates is reported. Under phosphine catalysis, a [4+3] cycloaddition for the formation of 1, 3‐dihydro‐2 H ‐azepine‐2, 2, 4‐tricarboxylates was achieved with broad substrate scope under mild reactions. A switchable process was given and a variety of important 2, 3‐dihydrochromeno[4, 3‐b]azepin‐6(1 H )‐ones were selectively formed when the reaction was performed in the presence of Cs2 CO3 and PPh3, which involved an intramolecular ester group migration and subsequent lactonization of 1, 3‐dihydro‐2 H ‐azepine‐2, 2, 4‐tricarboxylates. Besides easy handle process, high synthetic value of resulting products, it is worth to note that this work showed the novel example of 1, 5‐ethoxycarbonyl migration. Abstract :