Synthesis and ethylene-promoted metathesis of adducts of tandem [4+2]/[4+2] cycloaddition between bis-furyl dienes and maleic acid derivatives

• Published in: New journal of chemistry 2021-02, Vol.45 (7), p.34-347
• Main Authors: Kvyatkovskaya, Elizaveta A, Epifanova, Polina P, Nikitina, Eugeniya V, Senin, Aleksey A, Khrustalev, Victor N, Polyanskii, Kirill B, Zubkov, Fedor I
• Format: Article
• Language: English
• Subjects: Adducts; Crystallography; Cycloaddition; Dienes; Ethylene; Maleic acid; Maleic anhydride; Metathesis; NMR; Nuclear magnetic resonance; Stereochemistry; Structural analysis; Two dimensional analysis
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d0nj04528d

During this work, a series of 1,4:5,8-diepoxynaphthalenes, annellated with various carbo- and heterocycles, was synthesized based on the tandem intermolecular/intramolecular [4+2] cycloaddition of bis-furyl dienes with moderately to highly reactive cyclic dienophiles (maleic anhydride and maleinimides). The stereochemistry of the resulting adducts was established using 2D NMR and X-ray structural analysis, which showed that both successive Diels-Alder reactions led to single diastereoisomers of the target cycloadducts corresponding to the exo -transition state. The resulting hexacyclic compounds represent original polyfunctional synthons suitable for subsequent transformations, which has been demonstrated by the example of the ethylene-promoted ROCM reaction under new types of second-generation Hoveyda-Grubbs catalysts comprising a coordination N → Ru bond in a six-membered ring. As a result, the metathesis products, unsaturated 4,7-epoxyisobenzofurans, were obtained in satisfactory yields. A series of 1,4:5,8-diepoxynaphthalenes, annellated with carbo- and heterocycles, was synthesized based on the tandem intermolecular/intramolecular [4+2] cycloaddition of bis-furyl dienes with moderately to highly reactive cyclic dienophiles (maleic anhydride and maleinimides).