A new initiating system, (cyclopentadienyl) (π-allyl)­palladium­(II) [Cp­(π-allyl)­Pd], for the polymerization of diazoacetate monomers has been developed. Homo- and copolymers bearing an ester substituent at every main-chain carbon atom were efficiently synthesized from various alkyl and aryl diazoacetates. In particular, this polymerization system can tolerate various functional groups, which allows for effective postpolymerization functionalization of the resultant polymers. Detailed kinetic study indicates that this polymerization has the characteristics of slow initiation and rapid propagation. Furthermore, alcohols were found to function as chain transfer agents as confirmed by polymerization experiments and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analyses of the polymer products, thus providing an effective method for controlling the molecular weight of the polymer.

The Pd-catalyzed carbene coupling reaction of N-tosylhydrazones and benzyl bromides has been developed into a polymerization process for the first time, providing an efficient method for the synthesis of poly(arylene...

Alkyl chromium(0) carbene complexes have been explored as the cross-coupling partners in the palladium-catalyzed reaction with aryl or alkenyl boronic acids. This coupling reaction displays the versatile reactivities of alkyl chromium(0) carbenes under palladium catalysis. Mechanistically, this transformation is proposed to involve deprotonation of the alkyl chromium carbene substrate to generate a vinyl chromium anion intermediate that undergoes transmetalation to organopalladium species and reductive elimination.