The first Suzuki–Miyaura cross-coupling reactions of the synthetically versatile O-aryl carbamate and O-sulfamate groups is described. The transformations utilize the inexpensive, bench-stable catalyst NiCl2(PCy3)2 to furnish biaryls in good to excellent yields. A broad scope for this methodology has been demonstrated. Substrates with electron-donating and electron-withdrawing groups (EDGs, EWGs) are tolerated, in addition to those that possess ortho substitutents. Furthermore, heteroaryl substrates may be employed as coupling partners. A computational study providing the full catalytic cycles for these cross-coupling reactions is described. The oxidative additions with carbamates and sulfamates occur via a five-centered transition state, resulting in the exclusive cleavage of the Ar–O bond. Water is found to stabilize the Ni–carbamate catalyst resting state, and thus provides rationalization of the relative decreased rate of coupling of carbamates. Several synthetic applications are presented to showcase the utility of the methodology in the synthesis of polysubstituted aromatic compounds of natural product and bioactive molecule interest.

A new strategy for gold and palladium dual-catalytic reactivity and turnover, called catalyzed catalysis, enhanced the synthetic usefulness of vinylgold intermediates by providing dual-catalytic carbon-carbon cross-coupling as an alternative to protodemetalation. This protocol enabled the synthesis of substituted butenolides and isocoumarins from allyl esters. Kinetic and spectroscopic experiments support a mechanism in which the Lewis acidic gold complex catalyzes both an initial rearrangement step and a subsequent Lewis basic palladium oxidative-addition step.

The nickel-catalyzed Suzuki–Miyaura coupling of aryl halides and phenol-derived substrates with aryl boronic acids using green solvents, such as 2-Me-THF and t-amyl alcohol, is reported. This methodology employs the commercially available and air-stable pre-catalyst NiCl2(PCy3)2 and gives biaryl products in synthetically useful to excellent yields. Using this protocol, bis(heterocyclic) frameworks can be assembled efficiently.

A new palladium-catalyzed syn carboauration of alkynes proceeds in 2 h at ambient temperature with complete regioselectivity. The resulting α-ester vinyl−gold intermediates are resistant to rapid protodemetalation, permitting their participation in new one-pot palladium-and-gold cross-coupling reactions and electrophilic trapping reactions.

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