Bi(OTf) 3 -Catalysed Access to 2,3-Substituted Isoindolinones and Tricyclic N,O-Acetals by Trapping of Bis- N -Acyliminium Species in a Tandem Process
Abstract
Isoindolinones and tricyclic N,O‐acetals are obtained from bis‐N‐acyliminium precursors and assorted nucleophiles using catalytic Bi(OTf)3. The reactions proceed, respectively, through a double amidoalkylation or tandem π‐cyclisation/α‐oxa‐amidoalkylation. Mechanistic aspects of the tandem chemistry are supported by DFT calculations and its utility in RCM and Click reactions illustrated.
New 1,3‐bis‐N‐acyliminium species generated easily with nontoxic Bi(OTf)3 catalyst at very low loadings (2 mol‐%) were trapped inter‐ and intramolecularly with various poly‐nucleophiles. This mild, efficient, practical and general tandem approach provides an array of substituted isoindolinones and cyclic N,O‐acetals.