Rh(III)-Catalyzed Annulation of Boc-Protected Benzamides with Diazo Compounds: Approach to Isocoumarins

Abstract

A mild rhodium-catalyzed annulation of Boc-protected benzamides with diazo compounds via C−C/C−O bond formation has been explored. In the presence of [Cp*RhCl2]2, AgSbF6 and Cs2CO3, Boc-protected benzamides can be effectively annulated to yield isocoumarins in 0.5–2 h.

Transition‐Metal‐Catalyzed C−H Bond Functionalization of Arenes/Heteroarenes via Tandem C−H Activation and Subsequent Carbene Migratory Insertion Strategy

“…On a similar front, Liu and co-workers in 2019, reported a Rh(III)-catalyzed formation of isocoumarin derivatives via the coupling of protected benzamides with diazo compounds, thus providing an accessible way to construct these scaffolds under mild conditions (Scheme 45f). [147]…”

A Direct and an Efficient Regioselective Synthesis of 1,2-Benzothiazine 1,1-dioxides, β-Carbolinones, Indolo[2,3-c]pyran-1-ones, Indolo[3,2-c]pyran-1-ones, Thieno[2,3-c]pyran-7-ones and Pyrano[3’,4’:4,5]imidazo[1,2-a]pyridin-1-ones via Tandem Stille/Heterocyclization Reaction

“…Likewise, this strategy has been successfully extended to 3-iodothiophene-2-carboxylic acid and 3-iodoimidazo[1,2-a]pyridin-2-carboxylic acid to lead, with good yields, to thieno[2,3-c] pyran-7(7H)-one 5 and pyrano [3',4':4,5]imidazo [1,2-a]pyridin-1-one 6, respectively (entries 12 and 13). Note that few synthesis of this type of compound has been reported to date [51,52].…”

Metal-Free Stereoselective Synthesis of (E)- and (Z)-N-Monosubstituted β-Aminoacrylates via Condensation Reactions of Carbamates

“…The solids are collected by filtration, washed with hexane (50 mL), and dried under a combination of house vacuum/nitrogen sweep (inverted funnel connected to the N 2 source) to give tert -butyl (4-bromobenzoyl)­carbamate 61 (1.73 g, 82%) as an off-white solid. 1 H NMR is consistent with the known desired product . No further purification is required.…”