A DFT study on the formation of heterocycles via iodine(iii)-promoted ring expansion reactions

Abstract

The ring expansion of bicyclic heterocycles bearing an exocyclic double bond promoted by Koser's reagent [hydroxy(tosyloxy)iodobenzene, HTIB] is a mild, practical, and metal-free methodology to access seven-membered rings containing fused...

Reactivity and Stability of (Hetero)Benzylic Alkenes via the Wittig Olefination Reaction

“…During our study of heterocyclic ring expansion reactions using hypervalent iodine, we observed that some of the substrates prepared via Wittig olefination were easily isolated. However, some ketones were decomposed during the work-up process or obtained in very low yields upon exposure to the Wittig reaction [ 23 , 24 ]. To investigate the reason, we decided to observe the decomposition behavior of the expected alkenes via a series of heterocyclic substrates.…”

“…Sample appearance: Yellow viscous oil 1 H NMR (300 MHz, CDCl 3 ) δ: 1.88-1.96 (2H, q, J = 6.2 Hz), 2.42 (2H, t, J = 6.3 Hz), 2.87 (2H, t, J = 6.1 Hz), 3.10 (3H, s), 4.83 (1H, s), 5.10 (1H, s), 6.44 (1H, d, J = 3.3 Hz), 7.03 (1H, d, J = 3.3 Hz). 13 C NMR (75 MHz, CDCl [24].…”

“…1 H NMR (300 MHz, CDCl 3 ) δ: 1.78-1.85 (2H, q, J = 6.0 Hz), 2.49 (2H, t, J = 6.1 Hz), 2.87 (2H, t, J = 5.7 Hz), 3.39 (2H, s), 4.72 (1H, s), 4.75 (1H, s), 6.76 (1H, d, J = 5.1 Hz), 6.88 (1H, d, J = 5.1 Hz). 13 4-Methylene-4,5,6,7-tetrahydrobenzofuran (5b) [24]. The reaction was performed following the general protocol, using t-BuOK (0.84 g, 7.5 mmol), Ph 3 PCH 3 Br (2.68 g, 7.5 mmol) and 4b (0.68 g, 5.0 mmol) in anhydrous Et 2 O (15 mL).…”

Iodine(III)-Mediated Ring-Contraction Reactions Using Halogenated and Non-halogenated Solvents

“…[18][19][20] HTIB has garnered significant interest among researchers because of its economic viability and commercial availability. [21][22][23] The conversion process from 1,2-dihydronaphthalene (1) derivatives into the corresponding indane derivatives using HTIB is highly efficient and straightforward. 2 In our previous work, we utilized 1,2-dihydronaphthalene derivatives as substrates with HTIB to achieve ring-contracted products (indanes) with different functionalities.…”