Iron-Catalyzed Contrasteric Functionalization of Allenic C(sp<sup>2</sup>)–H Bonds: Synthesis of α-Aminoalkyl 1,1-Disubstituted Allenes
Yidong Wang, Yidong Wang, Sarah G. Scrivener, Xiao‐Dong Zuo, Ruihan Wang, Philip N. Palermo, Ethan Murphy, Austin C. Durham, Yiming Wang, Yiming Wang
Abstract
An iron-catalyzed C–H functionalization of simple monosubstituted allenes is reported. An efficient protocol for this process was made possible by the use of a newly developed electron-rich and sterically hindered cationic cyclopentadienyliron dicarbonyl complex as the catalyst and N-sulfonyl hemiaminal ether reagents as precursors to iminium ion electrophiles. Under optimized conditions, the use of a mild, functional-group-tolerant base enabled the conversion of a range of monoalkyl allenes to their allenylic sulfonamido 1,1-disubstituted derivatives, a previously unreported and contrasteric regiochemical outcome for the C–H functionalization of electronically unbiased and directing-group-free allenes.