Dearomatization Strategies in the Synthesis of Complex Natural Products

Abstract

Evolution in the field of the total synthesis of natural products has led to exciting developments over the last decade. Numerous chemo-selective and enantioselective methodologies have emerged from total syntheses, resulting in efficient access to many important natural product targets. This Review highlights recent developments concerning dearomatization, a powerful strategy for the total synthesis of architecturally complex natural products wherein planar, aromatic scaffolds are converted to three-dimensional molecular architectures.

Gold-Catalyzed Synthesis of 2-Sulfenylspiroindolenines via Spirocyclizations

“…It is now well established that indoles can react with alkynes in an intramolecular fashion, upon exposure to Au(I) or Au(III) catalysts, via either their positions 2 or 3 [1,3,6]. When the alkyne is tethered to the 3-position of the indole and if position 2 is substituted, the compound will undergo dearomatizing cyclization [7][8][9], as illustrated by the conversion of the 2-methyltryptamine derivative 1 (X = Me) into the spiro-compound 2 [10] (Scheme 1). In this field, we have introduced the use of 2-bromotryptamines that led to spirooxindoles 3 after acidic hydrolysis of the spirobromoindolenine resulting from the protodeauration of the intermediate [11][12][13].…”

Dearomatization of 3,5-dinitropyridines – an atom-efficient approach to fused 3-nitropyrrolidines

“…[1][2][3] In the last few decades, a significant interest in dearomatization of heterocyclic compounds has been observed. [2][3][4] This in turn has influenced the development of synthetic organic chemistry: many reactions have been used for carboncarbon and carbon-heteroatom bond formation in the construction of prospective biologically active compounds.…”

Antioxidant and cytotoxic properties of novel spirocyclic benzothiazolines

“…Due to their wide existance in bioactive natural products [10], spiroheterocycles have been focused on by researchers in chemistry and biology in the past decades. Indole phytoalexins are natural antimicrobial compounds produced by crucifers in response to biotic or abiotic stress [11].…”