Diastereoselective Synthesis of Dibenzoazepines through Chelation on Palladium(IV) Intermediates

Joint palladium/norbornene organometallic catalysis allows for straightforward access to dibenzo­[<i>c,e</i>]­azepines. These synthetically challenging polycyclic frameworks form in one pot via a three-component coupling of an aryl iodide, a bromobenzylamine, and an olefin. A key, atroposelective aryl–aryl coupling from chelated Pd­(IV) intermediates dictates the outcome of the cascade. DFT modeling sheds light on the complex mechanism that allows the complete diasteroselectivity to be observed

Diastereoselective Synthesis of Dibenzoazepines through Chelation on Palladium(IV) Intermediates

Joint palladium/norbornene organometallic catalysis allows for straightforward access to dibenzo­[<i>c,e</i>]­azepines. These synthetically challenging polycyclic frameworks form in one pot via a three-component coupling of an aryl iodide, a bromobenzylamine, and an olefin. A key, atroposelective aryl–aryl coupling from chelated Pd­(IV) intermediates dictates the outcome of the cascade. DFT modeling sheds light on the complex mechanism that allows the complete diasteroselectivity to be observed

Highly Enantioselective Rhodium-Catalyzed [2+2+2] Cycloaddition of Diynes to Sulfonimines

A new asymmetric [2+2+2] cycloaddition of diynes to sulfonimines under rhodium catalysis that provides the corresponding enantioenriched 1,2-dihydropyridines in good yields is described

An Improved Protocol for the Synthesis of [(η⁴-C₄R₄)Co(η⁵-C₅H₅)] Complexes

The reaction of bulky alkynes C₂R₂ with (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate) under microwave irradiation provides complexes of the type [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] in good to excellent yields. This protocol represents a significant improvement over those reported previously. In particular, the formation of insertion products such as cyclopentadienones or cyclohexadienes can be avoided. In addition, because of the exceptional stability of (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate), the reactions can be carried out in crude solvents. The easy access to [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] complexes stimulated a study of their reactivity, notably under cross-coupling conditions

An Improved Protocol for the Synthesis of [(η⁴-C₄R₄)Co(η⁵-C₅H₅)] Complexes

The reaction of bulky alkynes C₂R₂ with (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate) under microwave irradiation provides complexes of the type [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] in good to excellent yields. This protocol represents a significant improvement over those reported previously. In particular, the formation of insertion products such as cyclopentadienones or cyclohexadienes can be avoided. In addition, because of the exceptional stability of (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate), the reactions can be carried out in crude solvents. The easy access to [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] complexes stimulated a study of their reactivity, notably under cross-coupling conditions

An Improved Protocol for the Synthesis of [(η⁴-C₄R₄)Co(η⁵-C₅H₅)] Complexes

The reaction of bulky alkynes C₂R₂ with (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate) under microwave irradiation provides complexes of the type [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] in good to excellent yields. This protocol represents a significant improvement over those reported previously. In particular, the formation of insertion products such as cyclopentadienones or cyclohexadienes can be avoided. In addition, because of the exceptional stability of (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate), the reactions can be carried out in crude solvents. The easy access to [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] complexes stimulated a study of their reactivity, notably under cross-coupling conditions

An Improved Protocol for the Synthesis of [(η⁴-C₄R₄)Co(η⁵-C₅H₅)] Complexes

The reaction of bulky alkynes C₂R₂ with (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate) under microwave irradiation provides complexes of the type [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] in good to excellent yields. This protocol represents a significant improvement over those reported previously. In particular, the formation of insertion products such as cyclopentadienones or cyclohexadienes can be avoided. In addition, because of the exceptional stability of (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate), the reactions can be carried out in crude solvents. The easy access to [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] complexes stimulated a study of their reactivity, notably under cross-coupling conditions

An Improved Protocol for the Synthesis of [(η⁴-C₄R₄)Co(η⁵-C₅H₅)] Complexes

The reaction of bulky alkynes C₂R₂ with (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate) under microwave irradiation provides complexes of the type [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] in good to excellent yields. This protocol represents a significant improvement over those reported previously. In particular, the formation of insertion products such as cyclopentadienones or cyclohexadienes can be avoided. In addition, because of the exceptional stability of (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate), the reactions can be carried out in crude solvents. The easy access to [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] complexes stimulated a study of their reactivity, notably under cross-coupling conditions

An Improved Protocol for the Synthesis of [(η⁴-C₄R₄)Co(η⁵-C₅H₅)] Complexes

The reaction of bulky alkynes C₂R₂ with (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate) under microwave irradiation provides complexes of the type [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] in good to excellent yields. This protocol represents a significant improvement over those reported previously. In particular, the formation of insertion products such as cyclopentadienones or cyclohexadienes can be avoided. In addition, because of the exceptional stability of (η⁵-C₅H₅)­Co­(CO)­(dimethyl fumarate), the reactions can be carried out in crude solvents. The easy access to [(η⁴-C₄R₄)­Co­(η⁵-C₅H₅)] complexes stimulated a study of their reactivity, notably under cross-coupling conditions

Rearrangements of <i>N</i>‑Acyl Isothioureas. Alternate Access to Acylguanidines from Cyanamides

We report a tin-free one-pot radical approach to the synthesis of <i>N</i>-acyl isothioureas and acylguanidines from <i>N</i>-acyl cyanamides. Photoactivated reduction of aromatic disulfides in the presence of Hünig’s base results in hydrothiolation of the cyanamide moiety, followed by spontaneous 1,3-migration of the acyl group. Onward reaction of the isothioureas obtained with amines led to the corresponding <i>N</i>-acylguanidines, where the acyl group is attached to the nitrogen atom formerly at the cyano-end of the starting material