Synthesis, Crystal structure and DFT studies of Polyfunctionalized Alkenes: A transition Metal-Free C(sp2)-H Sulfenylation of electron deficient Alkyne

An efficient, novel and transition metal-free protocol has been developed for the synthesis of polyfunctionalized aminothioalkenes via direct C-H sulfenylation of in situ generated enamines. The reaction was performed using a catalytic amount of inexpensive and nontoxic K2CO3 under mild reaction condition. All the reactions resulted in good to excellent yields. The cross-coupling reaction has been achieved by in situ aerobic oxidation at room temperature with good functional group tolerance. The molecular architecture and stereochemistry has been established by spectral data, X-ray single crystal diffraction studies and supported by Density Functional theory (DFT). Hirshfeld surface analysis has been used to explore the intramolecular and intermolecular interactions present in the case of 4a . Moreover, the intramolecular hyperconjugative interactions have been investigated using natural bond orbitals (NBOs) analysis and their intensity was categorized according to their second-order stabilization energy (E(2)). The electrostatic properties such as global reactivity descriptors, local reactivity descriptors, ESP and NLO have been investigated using DFT method and B3LYP/6-311 +G(d) level of theory. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

An efficient and novel method for the synthesis of polyfunctionalized aminothioalkenes via direct C-H sulfenylation has been developed without the use of transition metals. Inexpensive and nontoxic K2CO3 was used as a catalyst under mild reaction conditions, resulting in good to excellent yields. Various analytical methods were employed to explore molecular structure, interactions, and electrostatic properties.