Recent Advances in Squaramide-Catalyzed Asymmetric Cascade Reactions for the Synthesis of Spirooxindoles

Abstract

Chiral spirooxindoles have captured huge attention from researchers in the area of organic chemistry and medicinal chemistry owing to their prevalence in various alkaloid natural products and pharmacologically active agents. In recent year, chiral bifunctional squaramide-catalyzed asymmetric cascade reaction of oxindoles or oxindole derivatives has become an efficient synthetic method for the construction of chiral spirooxindoes. In this review, the remarkable progress and advances in bifunctional squaramide-catalyzed asymmetric cascade reactions for the synthesis of spirooxindole derivatives from 2015 are summarized and discussed based on the different types of catalytic reactions.

Synthesis of difluoromethylated spiropyrazolones via [3 + 2] cycloaddition of difluoroacetohydrazonoyl bromides with alkylidene pyrazolones

“…3 As a consequence, significant efforts have been made to construct these highly valuable spiropyrazolone frameworks in the past decades. 4 On the other hand, as a more and more appealing fluorine-containing group, the difluoromethyl group (CF 2 H) is reported to have the ability to fine-tune the metabolic stability and bioactivities of many pharmaceutical and agrochemical molecules due to its lipophilic hydrogen-bond donor and weak acidity properties. 5 Consequently, the incorporation of the CF 2 H motif into organic molecules has received more and more attention in the design of lead pharmaceutical and agrochemical molecules in recent years.…”

Dehydroabietane-type bifunctional organocatalysts in asymmetric synthesis: recent progress

“…Chiral thioureas and squaramides are representative organocatalysts in asymmetric synthesis that have been developed for enantioselective reactions. 11–34 Owing to their specific strong hydrogen-bonding capabilities combined with the notable features of the dehydroabietane scaffold, a series of effective bifunctional organocatalysts based on the dehydroabietane structure have been employed in various catalytic asymmetric reactions so far. 11–26…”

Synthesis of Spiroindenyl-2-Oxindoles through Palladium-Catalyzed Spirocyclization of 2-Bromoarylamides and Vinyl Bromides

“…Spirooxindoles are ubiquitous in bioactive natural products and have found extensive applications in drug discovery [1][2][3][4][5][6][7]. On the other hand, spiroindenes have also gained considerable interest in medicinal chemistry [8][9][10][11][12][13]. The investigation of biological and pharmaceutical properties of spiroindenyl-2-oxindoles that contain both spiro-bridged indene and oxindole moieties is highly intriguing [14,15].…”