Density functional theory-supported studies of structural and electronic properties of substituted-phenol derivatives synthesized by efficient O- or C-arylation via Chan--Lam or Suzuki cross-coupling reactions

Abstract

The present study reports the efficient synthesis and computational studies of the structural and electronic properties of some interesting substituted phenol derivatives. Efficient and versatile procedures to synthesize a series of diaryl ether derivatives (2a-2c, 4a-4h) and bis-arylated products (5a-5c) are described. In this manuscript, using the commercially available starting material 1 and 3, a 1-step approach was developed by means of Cu(II)-mediated Chan-Lam and Pd-catalyzed Suzuki cross-coupling reactions to synthesize diaryl ether and bis-arylated products with moderate to good yields. The starting substrates, 2-bromo-4-methylphenol 1 or 2,4-dibromophenol 3, were both treated with several arylboronic acids, which led to the development of new carbon-oxygen bonds through Chan--Lam reactions. In addition, the hydroxyl group of 2,4-dibromophenol 3 was protected with isopropyl bromide to produce 4, which was then treated with arylboronic acids to synthesize the corresponding bis-arylated products through Suzuki cross-coupling reactions. Density functional theory calculations provided insight into the structural and electronic properties of the synthesized compounds. An analysis of the frontier orbitals and other reactivity descriptors, including the ionization potential, electron affinity, chemical hardness, electronic chemical potential, and electrophilicity index, is presented, which shows that compound 4c was the most reactive, while 4f and h were the most stable.