Rhodium(III) catalyzed synthesis of isoquinolone fused azabicycles through C–H activation of N-pivaloyloxy benzamides

Herein we describe an efficient one pot strategy toward highly functionalized isoquinolone fused azabicycles having great synthetic potential via C–H activation of N-pivaloyloxy benzamides under very mild conditions. The reaction is accomplished at room temperature within one hour in good to excellent yields and is found to be compatible with a range of diazabicyclic olefins and benzamides. The present strategy offers an easy route for the synthesis of biologically relevant compounds which possess multiple points for divergent synthesis. N–N bond cleavage of synthesized compounds may enable their significant role as effective precursors for the preparation of diaminocyclopentane fused isoquinolones.     

Rhodium(III)-catalyzed ring-opening of strained olefins through C–H activation of O-acetyl ketoximes: an efficient synthesis of trans-functionalized cyclopentenes and spiro[2.4]heptenes

An efficient strategy for the stereoselective synthesis of functionalized cyclopentenes and spiro[2.4]heptenes from strained olefins via C–H activation of aryl ketone O-acetyl ketoximes using [RhCl₂Cp^∗]₂ catalyst is described. The results revealed that a wide range of readily accessible aryl and heteroaryl ketoximes are compatible in this method for the ring opening of bicyclic and spirotricyclic olefins.     

Strain‐Promoted 1,3‐Dithiolium‐4‐olates–Alkyne Cycloaddition

Reported here is the reactivity of mesoionic 1,3‐dithiolium‐4‐olates towards strained alkynes, leading to thiophene cycloaddition products. In the process, the potential of these dipoles towards orthogonal reaction with azides, allowing efficient double ligation reactions, was discovered. A versatile process to access benzo[c]thiophenes, in an unprecedented divergent fashion, was developed and provides a new entry to unconventional polyaromatic thiophenes.     

Ruthenium catalyzed desymmetrization of diazabicyclic olefins to access heteroaryl substituted cyclopentenes through C–H activation of phenylazoles

The first ruthenium catalyzed redox-neutral C–H activation strategy for the ring-opening of diazabicyclic olefins via C–H bond cleavage of phenyl azoles is reported. The developed method offers a novel route to functionalized cyclopentenes by employing less-expensive ruthenium catalyst and readily accessible biologically significant heteroarenes. The present protocol is a merger of the C–H activation of phenyl substituted heteroaromatics and subsequent β-nitrogen elimination of diazabicyclic olefins.