Rhodium-Catalyzed Propargylic Substitution: A Divergent Approach to Propargylic and Allenyl Sulfonamides

Divergent Synthesis of Allenylsulfonamide and Enaminonesulfonamide via In(III)-Catalyzed Couplings of Propargylamine and N-Fluorobenzenesulfonimide

An In(III)-catalyzed facile and controllable method for the synthesis of allenylsulfonamide and enaminonesulfonamide has been achieved by the reaction between propargylamine and N-fluorobenzenesulfonimide (NFSI) under mild conditions. The present protocol is also applicable to the synthesis of tetrasubstituted allenylsulfonamide from triphenyl propargylalcohol. Experimental results suggest that the reaction probably proceeds through the ionic pathway.

Mechanism and reactivity of catalytic propargylic substitution reactions via metal–allenylidene intermediates: a theoretical perspective

The mechanism and reactivity of transition metal-catalyzed propargylic substitution reactions are summarized from a theoretical point of view.

Scope and advances in the catalytic propargylic substitution reaction

Nucleophilic displacement of the propargylic alcohol is one of the sought-after methods in the current scenario. The highly nucleophilic alkyne functional moiety along with its considerably acidic terminal hydrogen atom allows the propargylic unit to play a crucial role in organic synthesis by offering a handle for further synthetic transformations. Until 2000, the most fundamental propargylic substitution reaction was the Nicolas reaction, a multi-step transformation, developed in 1972, which involved cobalt as a stoichiometric promoter. Therefore, the direct catalytic substitution of propargylic alcohols was a highly desirable method for development. The pioneering work on the Ru-catalyzed propargylic substitution reaction in 2000 encouraged many researchers to develop several novel catalytic propargylic substitution reactions, which have made rapid progress since then. The purpose of this review is to emphasise the involvement of diverse types of Lewis acid, transition metal and Brønsted acid catalysts in the propargylic substitution reaction and provide an updated summary of the recent developments in this field. The selected examples presented here are the most significant and relevant ones and we believe that this will help the readers to comprehend the scope of the propargylic substitution reaction with diverse types of catalysts and will envisage the scientific community for the future developments in this field.

Direct nucleophilic displacement of the alpha-hydroxy of the propargylic alcohol is one of the sought-after methods in the current scenario. An updated summary of the recent developments in this field is presented here.

Rh-Catalyzed Stereospecific Synthesis of Allenes from Propargylic Benzoates and Arylboronic Acids

An enantiospecific approach to the synthesis of optically active, trisubstituted allenes from chiral propargylic benzoates and arylboronic acids has been developed. The transformation is catalyzed by a Rh-(P,olefin) complex formed in situ from [{Rh(cod)Cl}2] and a readily available phosphoramidite ligand. The method furnishes an assortment of diverse allenes in high yields and excellent enantiospecificity under mild conditions.

Transfer of chirality in the rhodium-catalyzed intramolecular [5+2] cycloaddition of 3-acyloxy-1,4-enynes (ACEs) and alkynes: synthesis of enantioenriched bicyclo[5.3.0]decatrienes

Chiral bicycles: Enantioenriched bicyclo[5.3.0]decatrienes were prepared from readily available chiral 3-acyloxy-1,4-enynes (ACEs) for the first time. In most cases, the chirality of the ACEs could be transferred to the bicyclic products with high efficiency. Inversion of the configuration was observed, thus confirming the predictions of previous computational studies.

How easy are the syntheses of allenes?

This short review highlights some of the recent important developments on the synthesis of allenes and its applications on the synthesis of some allenic natural products and allenic-based optoelectronic materials.

Ceric Ammonium Nitrate Promoted Oxidation of Oxazoles

The ceric ammonium nitrate promoted oxidations of 4,5-diphenyloxazoles and oxazoles with various substitution patterns have been investigated. This transformation results in the formation of the corresponding imide in good yield and tolerates a wide variety of functional groups and substituents on the oxazole moiety. [reaction: see text].