Chiminelli Maurizio, Scarica Gabriele, Serafino Andrea, Marchiò Luciano, Viscardi Rosanna, Maestri Giovanni
Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parco Area delle Scienze 17°, 43124 Parma, Italy.
ENEA, Casaccia Research Center, Santa Maria di Galeria, 00123 Roma, Italy.
Molecules. 2024 Jan 25;29(3):595. doi: 10.3390/molecules29030595.
Access to complex three-dimensional molecular architectures via dearomatization of ubiquitous aryl rings is a powerful synthetic tool, which faces, however, an inherent challenge to overcome energetic costs due to the loss of aromatic stabilization energy. Photochemical methods that allow one to populate high-energy states can thus be an ideal strategy to accomplish otherwise prohibitive reaction pathways. We present an original dearomative rearrangement of heteroaryl acryloylallenamides that leads to complex fused tricycles. The visible-light-promoted method occurs under mild conditions and tolerates a variety of functional groups. According to DFT modeling used to rationalize the outcome of the cascade, the reaction involves a sequential [2+2] allene-alkene photocycloaddition, which is followed by a selective retro- [2+2] step that paves the way for the dearomatization of the heteroaryl partner. This scenario is original with respect to the reported photochemical reactivity of similar substrates and thus holds promise for ample future developments.
通过普遍存在的芳基环的去芳构化获得复杂的三维分子结构是一种强大的合成工具，然而，由于失去芳香稳定能而面临克服能量成本的固有挑战。因此，能够使分子进入高能态的光化学方法可能是实现其他难以进行的反应途径的理想策略。我们展示了一种杂芳基丙烯酰基丙二烯酰胺的原始去芳构化重排反应，该反应可生成复杂的稠合三环化合物。这种可见光促进的方法在温和条件下进行，并且能耐受多种官能团。根据用于合理化级联反应结果的密度泛函理论（DFT）建模，该反应涉及连续的[2+2]丙二烯-烯烃光环加成反应，随后是选择性的逆-[2+2]步骤，这为杂芳基底物的去芳构化铺平了道路。就类似底物已报道的光化学反应性而言，这种情况是新颖的，因此有望在未来得到广泛发展。
