Abstract
Several charge-containing TADDOL salts were synthesized and used as organocatalysts in asymmetric Diels–Alder and hetero-Diels–Alder reactions. Their catalytic activity was found to exceed that of a noncharged analog while maintaining or improving upon the enantioselectivity. The enhanced activities of the TADDOL salts enabled them to act as presumed hydrogen bond donor catalysts in the Diels–Alder and hetero-Diels–Alder reactions of 1,3-cyclohexadiene with methyl vinyl ketone at 40°C and 2-phenoxy-1,3-butadiene with ethyl glyoxylate at room temperature, respectively. Given the ionic nature of these charge-activated catalysts, it also proved possible to recycle and reuse the TADDOL without chromatography or the need for a recrystallization.
| Original language | English (US) |
|---|---|
| Article number | e4355 |
| Journal | Journal of Physical Organic Chemistry |
| Volume | 35 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 2022 |
Bibliographical note
Funding Information:Generous support from the National Science Foundation (CHE‐1955186) and the Minnesota Supercomputer Institute for Advanced Computational Research are gratefully acknowledged. We also thank Dr. Victor G. Young Jr. and the X‐ray crystallography laboratory in the Department of Chemistry at the University of Minnesota for assistance in solving the reported crystal structure.
Publisher Copyright:
© 2022 John Wiley & Sons Ltd.
Keywords
- Brønsted acid catalysis
- TADDOL catalysis
- charge-activated acids
- hydrogen bond catalysis
- recyclable catalysts