Metal‐Free Alkyl(Aryl) Transfer‐Aromatization‐Alkylation Domino Approach: Facile Synthesis of Branched Hydroquinones from p‐Quinols and Diaryl Carbinols

• Published in: ChemistrySelect (Weinheim) 2017-05, Vol.2 (13), p.3622-3626
• Main Authors: Singh, Pallavi, Peddinti, Rama Krishna
• Format: Article
• Language: English
• Subjects: ATAAD approach; branched hydroquinones; diaryl carbinols; high atom economy; metal-free; p-quinols
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.201700445

Simple but effective and eco‐friendly metal‐free alkyl(aryl) transfer‐aromatization‐alkylation domino (ATAAD) approach was demonstrated to synthesize branched hydroquinones in good to excellent yields. This high atom economy approach proceeded through molecular iodine‐catalyzed aromatization of p‐quinols followed by C–C bond formation with diaryl carbinols. The use of inexpensive catalyst and easily accessible starting materials rendered this clean method more exciting for wide substrate scope to afford symmetrical and unsymmetrical branched hydroquinones. Short reaction time, easy workup and gram‐scale preparation are the significant features of this hitherto unknown synthesis of the title compounds. An efficient, metal‐free, eco‐friendly protocol for the direct access of branched hydroquinones has been developed. The developed protocol proceeded via alkyl(aryl) transfer‐aromatization‐alkylation domino (ATAAD) approach in high atom economical fashion. This efficient method notably enables the wide substrate scope with good to excellent yields. Economic ATAAD protocol allows the large scale preparation of branched hydroquinone in short reaction time and no tedious work‐up required.