Organocatalytic Asymmetric Assembly Reactions: Synthesis of Spirooxindoles via Organocascade Strategies

Abstract

Spirooxindoles have become a privileged skeleton given their broad and promising activities in various therapeutic areas. The strategies and catalyst systems described here highlight recent advances in the enantioselective synthesis of spirooxindoles via organocascade strategies. Various organocatalysts with distinct activation modes have found application in constructing these sophisticated compounds. This review focuses on the enantioselective synthesis of spirooxindoles via organocascade strategies and is organized on the basis of three primary starting materials and then further subdivided according to the types of organocatalyst. These methods are of importance for the synthesis of complex natural products and the design of new pharmaceutical compounds. We believe that compounds based on spirooxindole skeletons have the potential to provide novel therapeutic agents and useful biological tools.

Recent Progress in Organocatalytic Asymmetric Domino Transformations

“…[17][18][19][20][21][22][23][24][25][26][27][28][29] However, due to the extremelyf ast growthi no rganocatalyzed domino reactions,m anyn ew developments keep showing up on ad aily basis,w hich makes these reviews somewhat outdated very quickly.I na ddition, many of recentlyp ublished review articles on this topic are quite narrow in terms of theirs cope,f ocusing on either the synthesis of specific scaffolds or the processesm ediated by as pecific type of organocatalyst. [20][21][22][23][24][25][26][27][28][29] Due to the importance of this research and the fast developments in this area, we believe an ew review is needed and, in the present review,w ea re going to summarize the most recent developments in organocatalyzeda symmetric domino reactions,c overing the literature published from the beginning of 2012 up to May,2 017. Althoughs ome of the name reactions,such as the Mannich reactionand Biginelli reaction, are domino in nature,t hey are generally not covered in this review unless they are part of the entire domino reactions,b ecause there are many upto-date reviews out there dedicated to these name reactions.…”

Highly Stereoselective [4+2] and [3+2] Spiroannulations of 2‐(2‐Oxoindolin‐3‐ylidene)acetic Esters Catalyzed by Bifunctional Thioureas

“…, 21,1 1038 www.chemeurj.org electron-withdrawingg roups (EWG;T able 2, entries 2-4) or electron-donating groups (EDG;T able 2, entries 5-7), although both the yield and ee were affected by the position of the substituent( Table 2, entries 2a nd 3v s. entry 4). As ag eneral trend, oxindoles substituted with an EWG reacted faster than those with an EDG group (Table 2, entries 2-4 vs. entries [5][6][7].…”

“…[5] Indeed, organocascade processes have been recently employed in the enantioselective synthesiso fs pirocyclic oxindoles. [6] However, despite the considerable effort that has been made in this field, much work is needed to develop more flexible synthetic strategies, to expands tructurala nd stereochemical diversity, and extend the functionalpattern of spirocyclic oxindoles.…”

Synthesis of Isoxazolopyridines and Spirooxindoles under Ultrasonic Irradiation and Evaluation of Their Antioxidant Activity

“…Consequently, several protocols for the synthesis of isoxazoles and spirooxindoles have been reported [19][20][21][22][23][24][25][26][27][28].…”