Kowalska E, Bałczewski P. Ultrasound assisted Bradsher reaction in aqueous and non-aqueous media: First use of ultrasounds in electrophilic aromatic cyclisation leading to polyacenes.
ULTRASONICS SONOCHEMISTRY 2017;
34:743-753. [PMID:
27773301 DOI:
10.1016/j.ultsonch.2016.07.010]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 06/21/2016] [Accepted: 07/14/2016] [Indexed: 06/06/2023]
Abstract
The present work describes the first use of ultrasounds in the Bradsher cyclisation of activated and non-activated ortho-formyl diarylmethanes. This reaction is also the first example of electrophilic, aromatic cyclisation assisted by ultrasounds which leads to pure polycyclic, fused aromatic hydrocarbons containing 3 and 4 fused rings in excellent yields. The reaction proceeds not only in aqueous but also in non-aqueous media at milder conditions (room temperature) and in much shorter reaction times than in conventional protocols.
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