Efficient Benzimidazolidinone Synthesis via Rhodium-Catalyzed Double-Decarbonylative C–C Activation/Cycloaddition between Isatins and Isocyanates

The first decarbonylative cycloaddition of less-strained cyclic ketones (isatins) with isocyanates is reported. Initiated by C–C activation, this distinct [5 – 2 + 2] transformation provides a rapid entry to access various benzimidazolidinone derivatives, and a wide range of isocyanates can be efficiently coupled with broad functional group tolerance. A modified one-pot process combining a Curtius rearrangement and C–C activation was also achieved by using acyl azides as the starting materials. A detailed mechanistic study revealed a surprising double-decarbonylative reaction pathway. The novel reactivity discovered in this basic research is expected to shed light on the development of new heterocycle formation methods through C–C/isocyanate coupling

Efficient Benzimidazolidinone Synthesis via Rhodium-Catalyzed Double-Decarbonylative C–C Activation/Cycloaddition between Isatins and Isocyanates

The first decarbonylative cycloaddition of less-strained cyclic ketones (isatins) with isocyanates is reported. Initiated by C–C activation, this distinct [5 – 2 + 2] transformation provides a rapid entry to access various benzimidazolidinone derivatives, and a wide range of isocyanates can be efficiently coupled with broad functional group tolerance. A modified one-pot process combining a Curtius rearrangement and C–C activation was also achieved by using acyl azides as the starting materials. A detailed mechanistic study revealed a surprising double-decarbonylative reaction pathway. The novel reactivity discovered in this basic research is expected to shed light on the development of new heterocycle formation methods through C–C/isocyanate coupling

Efficient Benzimidazolidinone Synthesis via Rhodium-Catalyzed Double-Decarbonylative C–C Activation/Cycloaddition between Isatins and Isocyanates

The first decarbonylative cycloaddition of less-strained cyclic ketones (isatins) with isocyanates is reported. Initiated by C–C activation, this distinct [5 – 2 + 2] transformation provides a rapid entry to access various benzimidazolidinone derivatives, and a wide range of isocyanates can be efficiently coupled with broad functional group tolerance. A modified one-pot process combining a Curtius rearrangement and C–C activation was also achieved by using acyl azides as the starting materials. A detailed mechanistic study revealed a surprising double-decarbonylative reaction pathway. The novel reactivity discovered in this basic research is expected to shed light on the development of new heterocycle formation methods through C–C/isocyanate coupling

Cobalt-Catalyzed Intramolecular Alkyne/Benzocyclobutenone Coupling: C–C Bond Cleavage via a Tetrahedral Dicobalt Intermediate

A Co(0)-catalyzed intramolecular alkyne/benzocyclobutenone coupling through C–C cleavage of benzocyclobutenones is described. Co₂(CO)₈/P­[3,5-(CF₃)₂C₆H₃]₃ was discovered to be an effective metal/ligand combination, which exhibits complementary catalytic activity to the previously established rhodium catalyst. In particular, the C8-substituted substrates failed in the Rh system, but succeeded with the Co catalysis. Experimental and computational studies show that the initially formed tetrahedral dicobalt-alkyne complex undergoes C1–C2 activation via oxidative addition with Co(0), followed by migratory insertion and reductive elimination to give the β-naphthol products

Effect of Ring Functionalization on the Reaction Temperature of Benzocyclobutene Thermoset Polymers

The temperature required to induce cross-linking in typical benzocyclobutene-based thermosets is near 250 °C, which exceeds the use temperature of many chemical components. A new and versatile synthesis of BCB-functionalized monomers has allowed access to monomers that can be incorporated into a variety of macromolecular platforms to enable significantly reduced cure temperatures. Incorporation of BCB-functionalized comonomers in polystyrene and polynorbornene enabled insolublization of thin films by curing at only 120 °C for 1 h