Formation of allylated quaternary carbon centers C-O/C-O bond fragmentation of oxalates and allyl carbonates

• Published in: Chemical communications (Cambridge, England) Vol. 56; no. 3; pp. 454 - 457
• Main Authors: Chen, Haifeng, Ye, Yang, Tong, Weiqi, Fang, Jianhui, Gong, Hegui
• Format: Journal Article
• Published: 02.01.2020
• ISSN: 1359-7345; 1364-548X
• DOI: 10.1039/c9cc07072a

Disclosed herein emphasizes Fe-promoted cross-electrophile allylation of tertiary alkyl oxalates with allyl carbonates that generates all C(sp 3 )-quaternary centers. The reaction involves fragmentation of tertiary alkyl oxalate C-O bonds to give tertiary alkyl radical intermediates, addition of the radicals to less hindered alkene terminals, and subsequent cleavage of the allyl C-O bonds. Allylation with 2-aryl substituted allyl carbonates was mediated by Zn/MgCl 2 , and Fe is used to promote the radical addition efficiency. By introduction of activated alkenes, a three-component radical cascade reaction took place. Fe-Promoted reductive coupling of tertiary alkyl oxalates with allylic carbonates enables the formation of all C(sp 3 )-quaternary carbon centers via a double C-O bond fragmentation process.