Sequential C–C σ-Bond Cleavage/(sp2) C–O Bond Formation via C–H Functionalization toward Pyranoindolones Fused with Medium-Sized Rings

• DOI: 10.1021/acs.orglett.8b02580
• Publication Date: 2018-09-14T19:39:50Z
• Authors: Mengdan Wang; Lingkai Kong; Ye Wang; Bo Song; Yue Sun; Rong Tang; Yanzhong Li
• Keywords: Surface Modification; Bond cleavage; Cleavage (geology)

An atom-economical procedure for the synthesis of pyranoindolones fused with 7- or 8-membered rings has been developed. This process is realized through sequential Cs2CO3-promoted C–C σ-bond cleavage cyclic ketoesters and a ZnI2-mediated selective C–H/O–H coupling reaction. Two σ-bonds are cleaved one sp2 C–H bonds functionalized during reaction process. Easily accessible starting materials broad substrate scope make this protocol attractive in synthetic organic chemistry.