Synthesis of highly polarized [3]dendralenes and their Diels-Alder reactions

0576490 - ÚOCHB 2024 RIV GB eng J - Journal Article
Antal, R. - Staś, Monika - Perdomo, S. M. - Štemberová, M. - Brůža, Z. - Matouš, P. - Kratochvíl, J. - Růžička, A. - Rulíšek, Lubomír - Kuneš, J. - Kočovský, P. - Andris, Erik - Pour, M.
Synthesis of highly polarized [3]dendralenes and their Diels-Alder reactions.
Organic Chemistry Frontiers. Roč. 10, č. 22 (2023), s. 5568-5578. ISSN 2052-4129. E-ISSN 2052-4129
Research Infrastructure: e-INFRA CZ - 90140
Institutional support: RVO:61388963
Keywords : cross-coupling reactions * dendralenes * generation
OECD category: Physical chemistry
Impact factor: 5.4, year: 2022
Method of publishing: Open access
https://doi.org/10.1039/D3QO01221B

The diene-transmissive Diels-Alder (DTDA) reactions of dendralenes are emerging as a powerful synthetic tool. To date, these processes have been studied with non-polarized or mildly polarized species. We now present an expedient synthesis of strongly electron-deficient [3]dendralenes and demonstrate, for the first time, their DTDA reactions with electron-poor dienophiles. While the combination of two electron-poor partners is believed to be generally disfavored, DTDA reactions reported herein proceed at 100 & DEG,C with high yields and stereoselectivities. DFT calculations show that this electronically disfavored process is encouraged by a steric effect of the vinylic moiety within the dendralene core, driving the diene segment into the s-cis conformation, thereby lowering the activation energy by 2-3 kcal mol-1. While the free energy barrier is typically lower for the second cycloaddition, the two barriers become similar for dendralenes with a cyclic enone fragment, which allows a controlled stepwise addition of two different dienophiles.
Permanent Link: https://hdl.handle.net/11104/0346045


Research data: CCDC