Catalyst-directed access to divergent products involving three different metals that exclusively form three different products from the same reactants is reported. Each catalyst directs an individual metallo-enolcarbene pathway from enoldiazoacetates and alkenes to a specific product. These include highly selective intermolecular cyclopropanation catalyzed exclusively by dirhodium­(II) carboxylates, providing spiro-substituted dihydrooxazoles with greater than 20:1 diastereoselectivity and up to 99% ee; vinylogous addition with subsequent 1,6-proton transfer occurring independently with either Au­(I) or Cu­(I) catalysis or [3 + 2]-cycloaddition with a Cu­(II) catalyst; and direct cycloaddition with the CN bond of methylenedihydrooxazoles followed by rearrangement forming multiply substituted pyrroles in the presence of a silver catalyst. Allylic aromatization via vinylogous addition selectively delivers aromatic oxazole derivatives from methylenedihydrooxazoles, and when aromatization does not occur by 1,6-proton transfer, [3 + 2]-cycloaddition is the outcome. This catalyst-dependent formation of metallo-enolcarbene intermediates with alkenes demonstrates the tremendous potential of this approach to diversity-oriented-synthesis.

An unprecedented Ag I -catalyzed efficient method for the coupling of imino ethers and enol diazoacetates through a[3+ +2]-cycloaddition/CÀObond cleavage/[1,5]-proton transfer cascade process is reported. The general class of imino ethers that includes oxazolines,b enzoxazoles and benzimidates are applicable substrates for these reactions that provide direct access to fully substituted pyrroles with uniformly high chemo-and regioselectivity.H igh variability in substitution at the pyrrole 2-, 5-and N-positions characterizes this methodology that also presents an entry point for further pyrrole diversification via facile modification of resulting N-functional pyrroles.

An unprecedented Ag I -catalyzed efficient method for the coupling of imino ethers and enol diazoacetates through a[3+ +2]-cycloaddition/CÀObond cleavage/[1,5]-proton transfer cascade process is reported. The general class of imino ethers that includes oxazolines,b enzoxazoles and benzimidates are applicable substrates for these reactions that provide direct access to fully substituted pyrroles with uniformly high chemo-and regioselectivity.H igh variability in substitution at the pyrrole 2-, 5-and N-positions characterizes this methodology that also presents an entry point for further pyrrole diversification via facile modification of resulting N-functional pyrroles.