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A new class of polcyclic aromatic hydrocarbons - oligoindenopyrenes was prepared featuring a Pd-catalyzed Suzuki-Heck coupling cascade. It is observed that after excitation, the tetraindenopyrene derivative 3d undergoes efficient deactivation (99%) by internal conversion to the ground state and the small fluorescence quantum yield (0.004) is in accordance with the short ( 0.6 ns) fluorescence decay time.

Isolable quantities of [C.sub.60], the smallest stable fullerene, have been synthesized in 12 steps from commercially available starting materials by rational chemical methods. A molecular polycyclic aromatic precursor bearing chlorine substituents at key positions forms [C.sub.60] when subjected to flash vacuum pyrolysis at 1100 ° C. No other fullerenes are formed as by-products. The methods we have developed for the target-specific synthesis of fullerenes, applied here to a synthesis of [C.sub.60], should make possible the directed laboratory preparation of other fullerenes as well, including those not accessible by graphite vaporization., Although [C.sub.60] and some of the higher fullerenes can be readily prepared by resistive heating of graphite (1), there is still considerable interest in the rational stepwise synthesis of these [...]

Oxidative cyclization of 1,1E-binaphthyl to perylene is achieved in quantitative yield by the action of three or more equivalents of potassium metal in hot tetrahydrofuran. Anionic cyclodehydrogenations are complementary to those performed under strongly acidic/oxidizing conditions, photochemically, or thermally.

A report on the first examples of rhodium-catalyzed intermolecular [5+2] and [5+2+1] cycloaddditions of allenes incorporating alkynyl, alkenyl, cyano, and cyanoalkyl substituents is presented. These reactions proceed often in good to excellent yields, even at high temperatures, and low catalyst loading.

Research has been conducted on o-bromobenzeneboronic acid. The authors report that in the presence of palladium catalyst this acid can be coupled with 1-bromonaphthalene and with oligocyclic bromoarenes in order to produce indeno