An iron(II) chloride complex possessing a sterically demanding ortho-phenylene-tethered bisphosphine ligand shows a high catalytic activity in the KumadaTamaoCorriu coupling of nonactivated alkyl halides with aryl Grignard reagents. Primary, secondary, and tertiary alkyl halides can participate as an electrophilic coupling partner. A radical clock experiment using (iodomethyl)cyclopropane exclusively gives the corresponding ring-opening coupling product, suggesting intermediacy of alkyl radical species.Transition-metal-catalyzed cross-coupling is one of the most powerful tools in organic synthesis.1 After dormancy for decades, iron has attracted renewed attention as a practical coupling catalyst due to its economic and ecological advantages over the other rare metal catalysts.2,3 Moreover, iron catalyst displays characteristic reactivities and selectivities, which cannot be easily attained by the prevalent Ni-and Pd-catalysts: several research groups, including us, have reported the cross-coupling reactions of nonactivated alkyl halides with Grignard reagents by using iron catalysts. 3h3j,3m3o,3t,3u In 2004, we introduced TMEDA as a Lewis basic additive into the iron-catalyzed crosscoupling reaction to obtain the desired reactivity toward the alkyl halides.3h Although high selectivity and reactivity were achieved by using TMEDA with the optimized experimental procedure, large excess of the additive was required. In order to control the reaction by using a catalytic amount of additives instead of TMEDA, we continued the study and have developed new ortho-phenylenebisphosphine ligands, which bear peripheral steric bulk around the iron center. 4 We report herein a new KumadaTamaoCorriu coupling between various nonactivated alkyl halides and aryl Grignard reagents effected by low catalyst loading (0.5 to 3 mol %) of the ironbisphosphine complex.

Porous carbon material with a foam-like microstructure has been synthesized by direct carbonization of porous coordination polymer (PCP). In situ generation of foaming agents by chemical reactions of ligands in PCP during carbonization provides a simple way to create lightweight carbon material with a foam-like microstructure. Among several substituents investigated, the nitro group has been shown to be the key to obtain the unique foam-like microstructure, which is due to the fast kinetics of gas evolution during carbonization. Foam-like microstructural carbon materials showed higher pore volume and specific capacitance compared to a microporous carbon.

Control of pore distribution of porous carbons from porous coordination polymers.