Rh(iii)-catalyzed [4+1] annulation of a sulfoxonium ylide with allyl alkyl ethers: a detailed theoretical study of the anti-inflammatory and antidiabetic activities with DFT

Abstract

We propose a [4+1] annulation of sulfoxonium ylides with allyl ethers catalyzed by Rh(III), which leads to the formation of alkyl-substituted indanone derivatives. The reactions occur under mild conditions without external oxidants. The ylide serves as a traceless directing group in the subsequent annulation with allyl alkyl ethers via the (4+1) annulation. The process involves Csp²–H bond functionalization facilitated by AgBF₄, generating DMSO as a separable byproduct. This redox–neutral reaction exhibits a good substrate scope and excellent yields toward the various alkyl allyl ethers. The molecular structures of the title compounds (3a, 3b, and 3c) are optimized at the DFT/B3LYP/6-311++G(d,p) level of the basis set. The hyperpolarizability (β₀) values that are computed suggest that all molecules may behave in a nonlinear optical (NLO) manner. The Lewis (bonding) and non-Lewis (anti-bonding) structural types are calculated to investigate the intramolecular charge transfer inside the molecule. It appears that the molecule experiences intramolecular charge transfer based on the HOMO–LUMO transition. Understanding a molecule's reactive sites is possible by using its molecular electrostatic potential (MEP) surface. At various temperatures in the gas phase, the thermodynamic parameters of the title compounds, including entropy, heat capacity, and enthalpy, are calculated. Additionally, the anti-inflammatory and anti-diabetic performances of the above-synthesized compounds revealed better activity than their standard drug molecules.