A broadly general, three-component reaction strategy for the construction of compounds containing multiple heterocycles is described. Thermal benzyne formation (by the hexadehydro-Diels-Alder (HDDA) reaction) in the presence of tertiary cyclic amines and a protic nucleophile (HNu) gives, via ring-opening of intermediate ammonium ion/Nu- ion pairs, heterocyclic products. Many reactions are efficient even when the stoichiometric loading of the three reactants approaches unity. Use of HOSO2CF3 as the HNu gives ammonium triflate intermediates, which can then be ring opened by an even wider variety of nucleophiles.
Bibliographical noteFunding Information:
This work was supported by the U.S. Department of Health and Human Services, National Institute of General Medical Sciences (GM-65597). NMR spectral data were obtained with an instrument procured with a grant from the National Institutes of Health Shared Instrumentation Grant program (S10OD011952). We thank Mr. Juntian Zhang for performing the representative example of a 1 mmol scale reaction (see the SI).
© 2017 American Chemical Society.