Lewis-Base-Catalyzed Reductive Aldol Reaction To Access Quaternary Carbons
作者:Yvonne C. DePorre、James R. Annand、Sukanta Bar、Corinna S. Schindler
DOI:10.1021/acs.orglett.8b00507
日期:2018.5.4
transformation relies on an electronically differentiated Lewis base catalyst, which is uniquely capable of promoting a reductive aldol reaction of α,α-disubstituted and α,α,β-trisubstituted enones. This approach provides a valuable synthetic alternative for carbon–carbonbond formation in complex molecular settings due to its orthogonal reactivity compared to that of traditional aldol reactions. Based on this
carbon-terminated interrupted Nazarovreaction is described. The trimethylsilyl enol ethers derived from propargyl vinyl ketones undergo selective proton transfer at the distal acetylenic carbon atom to provide allenyl vinyl ketones as transient intermediates. In the presence of indoles, a cascade of reactions is initiated that converts the initially formed pentadienyl cations to cyclopentenones bearing