Transition-Metal-Free Multicomponent Benzannulation Reactions for the Construction of Polysubstituted Benzene Derivatives

Abstract

A transition-metal-free multicomponent benzannulation reaction was developed from readily available ketones, nitro-olefins, and diester acetylenedicarboxylate. This approach provides a straightforward and efficient way to construct polysubstituted benzene derivatives under mild conditions in high yields.

Benzannulation Reactions: A Case for Perspective Change From Arene Decoration to Arene Construction

“…This straightforward and efficient approach generated substituted benzene derivatives 136 in good yields (Scheme 42). [53] Xue has reported a 4-dimethylaminopyridine (DMAP)catalysed [2 + 2 + 2] benzannulation reaction of ethyl propiolate with 1,3-dicarbonyl compounds 137 or β-ketosulfones 138. DMAP functions as a nucleophilic promoter to assemble two molecules of the propiolate and one molecule of the active methylene compound into an arene ring.…”

Recent Progress in Transition‐Metal‐Free, Base‐Mediated Benzannulation Reactions for the Synthesis of a Diverse Range of Aromatic and Heteroaromatic Compounds

“…In 2015, the Wu group developed a transition‐metal‐free multicomponent benzannulation reaction of ketones, nitroolefins, and diester acetylenedicarboxylates (Scheme ) . In the presence of K 3 PO 4 , a Michael acceptor, diester acetylenedicarboxylate 4 , was attacked by 3‐oxonoate 5 to afford vinyl anion A , which was followed by a cyclization reaction with alkene 6 .…”

Iodine-mediated synthesis of 3-acylbenzothiadiazine 1,1-dioxides

“…On the other hand, despite that so many benzothiadiazine 1,1-dioxide derivatives have been studied extensively, 3-acylbenzothiadiazine 1,1-dioxides were ignored, because of the lack of efficient methods to prepare them. Readily available acetophenones have been shown to be good starting materials for the synthesis of various heterocyclic compounds [20–24]. The Wu group has reported an efficient protocol for the synthesis of luotonin F and derivatives from aromatic ketones and 2-aminobenzamides via iodination/Kornblum oxidation/annulation [25].…”