Regio- and stereoselective synthesis of 2-amino-dienes via decarboxylative amination of 4-(ethoxycarbonyl)-2,3-allenols by TsNCO

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

The allene functionality has participated in one of the most exciting voyages in organic chemistry, from chemical curiosities to a recurring building block in modern organic chemistry. In the last decades, a special kind of allene, namely, allenol, has emerged. Allenols, formed by an allene moiety and a hydroxyl functional group with diverse connectivity, have become common building blocks for the synthesis of a wide range of structures and frequent motif in naturally occurring systems. The synergistic effect of the allene and hydroxyl functional groups enables allenols to be considered as a unique and sole functionality exhibiting a special reactivity. This Review summarizes the most significant contributions to the chemistry of allenols that appeared during the past decade, with emphasis on their synthesis, reactivity, and occurrence in natural products.

Palladium-catalyzed C-P cross-coupling of allenic alcohols with H-phosphonates leading to 2-phosphinoyl-1,3-butadienes

The first facile, efficient, atom-economical and regioselective palladium-catalyzed direct C-P cross-coupling of unprotected allenic alcohols with H-phosphonates for the one-pot synthesis of structurally diverse multisubstituted 2-phosphinoyl-1,3-butadienes was developed. This strategy would enrich the allene chemistry and afford new scaffolds to construct complex molecular skeletons.

Modern Synthetic Methods for the Stereoselective Construction of 1,3-Dienes

The 1,3-butadiene motif is widely found in many natural products and drug candidates with relevant biological activities. Moreover, dienes are important targets for synthetic chemists, due to their ability to give access to a wide range of functional group transformations, including a broad range of C-C bond-forming processes. Therefore, the stereoselective preparation of dienes have attracted much attention over the past decades, and the search for new synthetic protocols continues unabated. The aim of this review is to give an overview of the diverse methodologies that have emerged in the last decade, with a focus on the synthetic processes that meet the requirements of efficiency and sustainability of modern organic chemistry.

Recent advances in reactions of aryl sulfonyl isocyanates

Aryl sulfonyl isocyanates are important intermediates in organic synthesis. They are used as electrophilic reagents and easily react with nucleophiles to form amides, sulfonyl ureas, pyrrolidine derivatives, lactams, oxazolidinones, and so on. Although there are some reviews on the applications of isocyanates in chemistry, few are concerned about aryl sulfonyl isocyanates. This review focuses on recent advances related to aryl sulfonyl isocyanates in organic synthesis, mainly including three special characteristics. The mechanisms of the typical reactions are also discussed.

[3,3]-Sigmatropic rearrangement of allenic alcohols: stereoselective synthesis of 1,3-diene-2-ol sulfonates

An efficient synthetic pathway to 1,3-diene-2-ol sulfonates involving the [3,3]-sigmatropic rearrangement of allenic alcohols with sulfonic acids under mild reaction conditions is described. These products can easily undergo reduction or transition-metal catalyzed cross-coupling reactions to yield a series of stereodefined multisubstituted 1,3-dienes.

Cu-Catalyzed hydrophosphorylative ring opening of propargyl epoxides: highly selective access to 4-phosphoryl 2,3-allenols

A CuI-catalyzed cross-coupling of propargyl epoxides with P(O)H compounds to produce 4-phosphoryl 2,3-allenols with excellent selectivity under mild conditions is disclosed.