An operationally simple nickel-catalyzed hydroarylation reaction for alkynes is described. This threecomponent coupling reaction utilizes commercially available alkynes and aryl bromides, along with water and Zn. An airstable and easily synthesized Ni(II) precatalyst is the only entity used in the reaction that is not commercially available. This reductive cross-coupling reaction displays a fairly unusual anti selectivity when aryl bromides with ortho substituents are used. In addition to optimization data and a preliminary substrate scope, complementary experiments including deuterium labeling studies are used to provide a tentative catalytic mechanism. We believe this report should inspire and inform other Ni-catalyzed carbofunctionalization reactions.

We report on a study of laser-induced nucleation (LIN) of sodium chlorate in supersaturated aqueous solutions using focused nanosecond laser pulses at high energy densities (420 kJ cm -2 ). On irradiation with a single laser pulse, optical breakdown was observed in the form of a luminous plasma, and numerous microbubbles were produced. Based on the observations, we estimate the energy threshold for optical breakdown in the solutions to be 70 J cm -2 . Remarkably, even at high energy densities, single laser pulses produced on average only one or two crystals. The mean number of crystals obtained was 1.5 (532 nm) and 1.8 (1064 nm) per sample (3 cm 3 ). The effect of left circularly polarized (LCP) and right circularly polarized (RCP) light on the nucleation of dextrorotatory (d) versus levorotatory (l) enantiomorphs of cubic (phase I) sodium chlorate crystals was investigated. No significant correlation between the helicity of circular polarization and the chirality of enantiomorph was observed. The results are consistent with a mechanism involving nucleation of the achiral monoclinic phase III followed by solid-solid transformation to the chiral cubic phase I of sodium chlorate, although this transformation was not observed directly. The use of single-pulse LIN at high pulse energy densities may be useful in exploration of polymorphs, or in production of single crystals for analysis.

THE technique for catalytic fluorination has been iniproved to such an extent that a desired saturated fluorocarbon may be produced in moderate to high yield b v the reaction of the corresponding hydrocarbon with elementary fluorine. The hydrocarbon vapor and the fluorine are each diluted by nitrogen and are gradually mixed iu the presence of fine copper turnings or ribbon coated with a thin layer of silver fluorides. This procedure has been used to produce straight or branchedchain fluorocarbons ranging from perfluorobutane to perfluorohexadecane and naphthenic fluorocarbons from C6Flz to Cl8F30. Volatile hydrocarbon lubricating oils have also been fluorinated. It appears probable that the fluorocarbons are produced by the action of the fluorinating agent, AgFz, upon the hydrocarbon vapor and that the supply of the silver difluoride in maintained by the reaction: 2AgFz f Fz ---.f 2AgF2.

It is demonstrated that laser-induced nucleation enables preferential crystallization of metastable anhydrous solids from solution.