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Water-soluble aliphatic phosphines Cy 2 P(CH 2 ) 2 N(CH 3 ) 3 + Cl -(14), Cy 2 P[4-(N,N-dimethylpiperidinium)] + Cl -(15), Cy 2 P(CH 2 ) 2 SO 3 -Na + (16), and CyP[(CH 2 ) 2 N(CH 3 ) 3 + Cl -] 2 (17) (Cy ) cyclohexyl) were prepared from air-stable, borane-protected precursors. Spectroscopic investigations of corresponding Pd(PR 3 ) 2 Cl 2 complexes were used to estimate the steric parameters of these new phosphines. Spectroscopic investigation of Ni(CO) 3 PR 3 complexes of the new phosphines indicated that phosphines bearing quaternary amine functionalities were less electron donating than tricyclohexylphosphine, while the presence of a sulfonate group increased phosphine electron donation. Cationic phosphines 14 and 15 were used to synthesize water-soluble ruthenium carbene complexes of the type (Cy 2 PR) 2 Cl 2 RudCHPh. These complexes initiate the ring-opening metathesis polymerization (ROMP) of functionalized 7-oxanorbornenes in water, methanol, and aqueous emulsions.

Ruthenium alkylidenes 6 and 7 bearing cationically functionalized phosphine ligands are soluble and stable in protic solvents and initiate olefin metathesis reactions in methanol, water, and aqueous emulsions. NMR spectroscopy data and X-ray diffraction analyses of alkylidene 6 suggested that these new alkylidenes were structurally similar to previously reported complexes of the type (PR 3 ) 2 Cl 2 RudCHR, in which the alkylidene substituents lie in the Cl-Ru-Cl plane. The anionic chloride ligands of complexes 6 and 7 were found to undergo facile ligand exchange reactions with other anions in protic solution. Both alkylidenes initiate the ring-opening metathesis polymerization (ROMP) of strained, cyclic olefins in water. However, the propagating species in these reactions decompose prior to complete consumption of monomer. These complexes initiate the quantitative, living polymerization of functionalized monomers in water in the presence of a Brønsted acid. Both chain termination and chain transfer reactions were experimentally demonstrated to be absent on the time scale of these acid-activated polymerizations. Alkylidenes 6 and 7 react readily with acyclic olefins: alkylidene 6 reacted with trans-2-butene to yield a new ethylidene complex in either methanol or water, and the treatment of 6 with tri(ethylene glycol) methyl vinyl ether in water yielded water-soluble Fischer-carbene complex 16.

COMMUNICATIONS ethane (33.3 mol%) and nitrogen, with or without any additive (higher alkanes or olefins), as the feed at a space velocity of 6100+_ 100 cm3 g-' h-* w' ith a squarepulse technique descrlbed earlier [21]. The space velocity was measured at 0 "C and 1 atm. Conversion X in %, S,, in %, and yield of arene based on ethane conversion ( YArlCIHs) in %) were determined as follows: X = [{(wt% of reactant in the feed hydrocarbons) -(wt% of reactant in the product hydrocarbons)}/(wt% of reactant in the feed hydrocarbons)] x 100; S,, = [(wt% of arenes in the hydrocarbon products)/{l00 -wt% of reactant(s) in the hydrocarbon products]] x 100; YAr,Cz",, = (XS*,)/~OO.Angew (%en?. Int. G I EngI. 1997, 36, N o . 12 :(; VCH Ve~lrigsgesrilrcbfi~ mhH, 0-69451 Wi+diein?. I997 0570-OH33!Y7~3612-1309 S 17.56 +.SO 0 Experimental Section General procedure for ruthenium benzylidene catalyzed RCM : Under exclusion from air and moisture, 1 (5 mol%) in CH,CI, was added to a 0.01 M solution of the diolefin (typically 200 to 900 mg) in CH,CI,. After the mixture was stirred for 6 h at room temperature, additional catalyst (5 mol%) was added, and stirring continued for 6 h. The solvent was then removed under reduced pressure, and the crude reaction mixture purified by repeated column chromatography (silica gel, CH,CI,/ MeOH 9614 viv) to yield the [2]catenates as burgundy solids. All compounds were characterized by NMR spectrscopy, FAB-MS, and elemental analysis.