Catellani Reaction: An Enabling Technology for Vicinal Functionalization of Aryl Halides by Palladium(0)/Norbornene Cooperative Catalysis

Abstract

The Catellani reaction, originally discovered by Catellani in 1997, and further developed by Catellani, Lautens and others, has emerged as a powerful strategy for the synthesis of polysubstituted arenes, which would be difficult to access via traditional methods. In this process, both ortho-and ipso-positions of aryl halides could be functionalized simultaneously with different electrophiles and terminating agents under the cooperative catalysis of palladium and norbornene (NBE). This review focuses on the significant progress of such transformations, and the section of typical Catellani reactions is divided into five parts according to the functionalization mode of ortho-C-H bond: alkylation, arylation, amination, acylation or thiolation.

Research advances in palladium-catalysed intermolecular C–H annulation of aryl halides with various aromatic ring precursors

“…Alternatively, the development of transient directing groups has attracted considerable interest from synthetic organic chemists. 5,6 The most typical reaction is the palladium-catalysed C–H functionalization of aryl halides. 6 The reaction undergoes oxidative addition of Pd(0) to a C–X bond, followed by carbopalladation/C–H activation or direct C–H activation to form C , C -palladacycles, which then achieve transformation by reductive elimination or trapping with coupling reagents.…”

“…5,6 The most typical reaction is the palladium-catalysed C–H functionalization of aryl halides. 6 The reaction undergoes oxidative addition of Pd(0) to a C–X bond, followed by carbopalladation/C–H activation or direct C–H activation to form C , C -palladacycles, which then achieve transformation by reductive elimination or trapping with coupling reagents. Among them, palladium-catalysed intermolecular C–H functionalization of aryl halides is extremely attractive due to the introduction of external reagents.…”

Trifunctionalization of aryl iodides via intermolecular C–H acylation/intramolecular C–H alkylation achieved using palladium/norbornene cooperative catalysis

“…1 In this respect, palladium/norbornene (Pd/NBE) catalysis, which was pioneered by Catellani, 2 has been shown to provide a facile method for the synthesis of complex 1,2,3-trisubstituted arenes. 3–6 In general for these reactions, an electrophile ( E ) and a nucleophile ( Nu ) are coupled at the ortho and ipso positions of aryl iodides by taking advantage of a pivotal aryl-NBE palladacycle ( ANP ) intermediate, allowing two functionalizations to be achieved simultaneously (Scheme 1A). 5 Notably, when ortho -unsubstituted haloarenes are used, the second C−H activation would generally take place to form another aryl-NBE palladacycle ( ANP′ ) intermediate, affording symmetrical trisubstituted arenes.…”

Total Synthesis of Dalesconol A by Pd(0)/Norbornene-Catalyzed Three-Fold Domino Reaction and Pd(II)-Catalyzed Trihydroxylation

“…Transition-metal-catalyzed C–H functionalization has become a versatile tool for forging new reliable methods and their further applications in the synthesis of complex molecules . Among them, palladium(0)/norbornene (NBE) catalysis, originally discovered by Catellani, represents an extraordinarily useful strategy for making polysubstituted arenes via simultaneous ortho and ipso functionalization of aryl halides . Notably, with reliance on the successful use of bifunctional reagents, which was pioneered by Lautens, a variety of synthetically useful fused-ring scaffolds could be rapidly assembled .…”

“…Among them, palladium(0)/norbornene (NBE) catalysis, originally discovered by Catellani, represents an extraordinarily useful strategy for making polysubstituted arenes via simultaneous ortho and ipso functionalization of aryl halides . Notably, with reliance on the successful use of bifunctional reagents, which was pioneered by Lautens, a variety of synthetically useful fused-ring scaffolds could be rapidly assembled . In this context, by employing such Pd(0)/NBE-catalyzed reactions as the key steps to build molecular skeletons, the groups of Lautens, Gu, Dong, and Zhou have respectively completed the total syntheses of linoxepin, rhazinal, rhazinilam, kopsiyunnanine C1–3, fufenozide, pauciflorol F, acredinone A, eptazocine, and berkelic acid .…”