Recent Advances in the Reactions of 1,2-Allenic Ketones and α-Allenic Alcohols

Abstract

This Personal Account summarizes our recent efforts in searching for novel synthetic strategies for a number of organic molecules by using allene derivatives as valuable substrates. It starts with a concise description of the background of allene-related synthetic chemistry. The second part deals with the reactions of 1,2-allenic ketones, including the reactions of 1,2-allenic ketones with various nucleophiles to afford functionalized benzenes, heterocycles, and fluoroenones, and those of allenic ketones as nucleophiles under the promotion of bases to provide 1,3,4'-triones or functionalized furans. The third part of this account focuses on the reactions of α-allenic alcohols. In this section, multicomponent reactions involving α-allenic alcohols, and cascade reactions of α-allenic alcohols promoted by Brønsted acid or iodine, are presented.

Highlighting the Rich Chemistry of the Allenone Moiety

“…Besides, choosing the adequate substituent can also modulate the allene reactivity providing divergent transformations, especially when electron‐donating or electron‐withdrawing groups are attached to the allene system. Among the family of electronically tuned allenes, allenones, constituted by an allene moiety and a ketone, have appeared as recurring motifs in organic synthesis, natural products and mechanistic investigations, showing unique properties and synthetic applications [10–22] …”

Deciphering the Chameleonic Chemistry of Allenols: Breaking the Taboo of a Onetime Esoteric Functionality

“…In the last decades, a special kind of allene, namely, allenol, has emerged in both organic and physical organic chemistry, becoming a common building block for the synthesis of a wide range of structures.. − Allenols are formed by an allene and a hydroxyl functional group showing diverse connectivity. The synergistic effect of one functional group over the other when sharing the same skeleton makes the allenol unit a unique and sole functional group exhibiting a special reactivity.…”

Synthesis of Functionalized Cyclobutane‐Fused Naphthalene Derivatives via Cascade Reactions of Allenynes with tert‐Butyl Nitrite

“…[3,4] Conventional methods for this purpose usually use nitric acid as the nitrating reagent and another strong acid as the catalyst, which often cause poor selectivity and produce corrosive wastes. [7] In this regard, Jiang and co-workers have recently disclosed some interesting domino transformations of allenynes. [6] Allene derivatives are highly valuable in synthetic chemistry owing to their rich reactivity and ready availability.…”

“…[6] Allene derivatives are highly valuable in synthetic chemistry owing to their rich reactivity and ready availability. [7] In this regard, Jiang and co-workers have recently disclosed some interesting domino transformations of allenynes. [8] Inspired by those pioneering studies and as a continuation of our own interests in allene derivatives [7c,9] and TBN, [10] we envisioned a synthesis of nitrocyclobutane-fused 2-nitronaphthalen-1-ol (A, Scheme 1).…”