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Enynones are powerful synthons for constructing furan derivatives in the presence of transition metal catalysts. Unlike the conventional intramolecular nucleophilic attack with the activation of coinage metals, we propose that enynones undergo an oxidative cyclization process with a Pd(0) species. The full catalytic cycle involves oxidative cyclization, isocyanide insertion, and reductive elimination, which was supported by DFT calculations. Geometric and electronic analyses confirmed the oxidative cyclization process, which proceeds VIA a Pd(II) intermediate. [ABSTRACT FROM AUTHOR]

In the presence of multiple electrophiles, the reaction sequence is a critical mechanistic problem. Here, we report a theoretical study on the mechanism of phosphine-catalyzed [8+2] cycloaddition of heptafulvenes and allenoate. DFT calculations showed that electrophilicity is the barrier for nucleophilic attack, while it fails in the prediction of priority. [ABSTRACT FROM AUTHOR]

A mixture of pathways including the use of catalyst was proposed for a dirhodium-mediated triazole activation–cycloaddition. This proposal was supported by the results of density functional theory (DFT) calculations, and was indicated to involve a non-catalyzed cleavage of the triazole N–N bond followed by a dirhodium-assisted denitrogenation. Electron-deficient carboxylates were found to be favourable for the rate-determining denitrogenation step. [ABSTRACT FROM AUTHOR]

Theoretical calculations have been performed to investigate the mechanism and stereoselectivity of rhodium-catalysed intramolecular [3+2] cycloaddition for construction of a substituted hexahydropentalene complex. A new C–C bond cleavage mechanism, retro-Aldol-type, is proposed and verified for this Rh-catalysed [3+2] cycloaddition reaction. [ABSTRACT FROM AUTHOR]