Ruthenium-Catalyzed Hydroxyl-Directed peri-Selective C–H Activation and Annulation of 1-Naphthols with CF₃–Imidoyl Sulfoxonium Ylides for the Synthesis of 2-(Trifluoromethyl)-2,3-dihydrobenzo[de]chromen-2-amines

Abstract

A ruthenium-catalyzed peri-selective C–H activation and annulation of 1-naphthols with CF3-substituted imidoyl sulfoxonium ylides that uses hydroxyl as a weakly coordinating directing group is disclosed. The strategy provides a facile and practical route to diverse trifluoromethyl-containing 2,3-dihydrobenzo­[de]­chromen-2-amines with high efficiency. Notable advantages of this protocol include readily available materials, excellent regioselectivity, good functional group compatibility, and scalability.

Enantioselective Access to C-N Axially Chiral Isoquinolones via Dynamic Kinetic Transformation of Carbene Reagents: Unique Chiral Induction Enabled by Dual Role of the Catalyst

“…Our design boils down to development of new coupling reagents that are both bulky and reactive. To reconcile these seemingly contradictive criteria, we employed a bifunctional carbene reagent such as CF3-imidoyl sulfoxonium ylides (TFISYs) [57][58][59][60][61][62][63][64][65] bearing a proximal nucleophilic imine nitrogen as well as a bulkyl N-aryl group (Scheme 1c). Consequently, a secondary amide bearing an electrophilic directing group [66][67][68][69][70][71] was applied as the C-H substrate.…”

“…acrylamide and other heteroarene-derived amides failed to undergo any coupling(65)(66)(67).The scope of the ylide reagent was also extensively examined. Introduction of a wide variety of substituents (alkyl, aryl, OMe, halogen, or OCF3) into the para or meta position of the N-(ophenyl) ring of the imidoyl sulfoxonium ylide was fully tolerated (33-42, 89-94% ee), and the bulky N-aryl group was also extended to an N-(o-(2-naphthyl)phenyl) group (50, 93% ee).…”

Rhodium(iii)-catalyzed regioselective C2-alkenylation of indoles with CF3-imidoyl sulfoxonium ylides to give multi-functionalized enamines using a migratable directing group

“…9 Our group also utilized TFISYs as CF 3 -containing synthons to successfully build CF 3 -decorated pyrazoles and benzo[de]chromen-2-amines. 10 Inspired by the aforementioned seminal works about TFISYs and our continuous interest in the construction of trifluoromethyl-containing N-heterocycles using different trifluoromethyl synthons, 11 we wish to report our findings of rhodium( iii )-catalyzed regioselective C2-alkenylation of indoles with TFISYs to furnish a wide range of indolyl- and trifluoromethyl-decorated enamines in moderate to good yields. In this protocol, TFISYs are firstly applied as convenient masked alkenylating agents in directed C–H functionalizations and a directing group migration cascade occurs to enable the formation of the desired enamine products.…”

Rh(III)-Catalyzed Dual C–H Activation/Cascade Annulation of Benzimidates and CF3-Imidoyl Sulfoxonium Ylides for the Synthesis of Trifluoromethyl-Decorated Benzo[de][1,8]naphthyridines

“…Based on the preliminary mechanistic studies and the precedent reports, ,,, a tentative reaction mechanism for this cascade annulation reaction was proposed (see Scheme S1 in the Supporting Information). A dual Rh-catalyzed C–H activation and annulation sequence was considered to be involved in the transformation, with the extrusion of DMSO, EtOH, and amine.…”

“…CF 3 -substituted imidoyl sulfoxonium ylides (TFISYs) are an important class of trifluoromethyl-containing synthons and have been adopted to synthesize various trifluoromethyl-substituted heterocycles, such as pyrazoles, pyrroles, pyridones, and isoquinolinones . Considering the extensive application of α-carbonyl sulfoxonium ylides in transition-metal-catalyzed C–H bond functionalizations and the two reported examples of the application of TFISYs in the field of C–H activation, , we envision that the merger of benzimidates with TFISYs in a multistep C–H activation/annulation reaction could lead to trifluoromethyl-substituted fused heteroaromatic compounds. Prompted by our continuous interest on exploiting efficient strategies for the synthesis of trifluoromethyl-containing heterocycles using diverse trifluoromethyl building blocks, we herein disclose a Rh­(III)-catalyzed dual C–H activation and cascade annulation of readily available benzimidates with TFISYs for accessing trifluoromethyl-decorated benzo­[ de ]­[1,8]­naphthyridines in moderate to excellent yields (Scheme d).…”