No abstract

Carbonyl ylides (I; Scheme 1) can be obtained by reactions of carbenes and carbenoids with aldehydes and ketones['.21 or by electrocyclic ring opening of ~xiranes.[~] As 1,3-dipole~[~~ they are mechanistically and preparatively of interest for heterocycle syntheses, and can be detected by intra-and intermolecular trapping reactions.['] In reactions of carbonyl compounds with organophosphorus carbene analogues, such as phosphanediyls, electrophilic, terminal phosphanediyl metal complexes,[5] iminophosphanes,C6' or metallodiph~sphenes,[~~ the formation of phosphorus analogues (XI-V) of carbonyl ylides has not yet I II PR 111 I V V Scheme 1. Carbonyl ylides (I) and organophosphorus analogues (11-V) (R = alkyl, aryl; [MI = metal complex fragment).

COMMUNICATIONS (0.8 g, 36 mmol) in THF at -20" under nitrogen was added nBuLi in hexane (2.5h1, 1.5 mL, 36 mmol) with stirring. The reaction mixture was cooled to -78", and AgCIO, (0.74 g. 36 inmol) in THF added. After 30 min a solution of 2,4-dinitrobenzenesulfenyl chloridc (0.84 g, 36 mmol) in THF was added dropwise. The temperature was allowed to rise to room temperature, and stirring maintained for 20 h. The solid residue was removed by filtration, and the filtrate purified by chromatography on silica gel with pet-oleum ether (40-60)/CH2C1, (3/1) as eluent. Compound 6 was obtained in 46% yield (0.7 g); m.p. 145-146' (methanol); HRMS (CI) calcd for C,,H,,N,O,S ( M t l ) : 422.117; found: 422.319. Resolution of 6 : ? = 0" , Chiralpak-AD column (25 x 0.46 cm) packed with dimethylphenylcarbamoylamylose from DAICEL Chemical, hexane/2-propanol (7/3), Waters 996 HI'LC instrument. Retention times of the enantiomers: 8.5 and 21.5 min. Selective inversion was applied by the sequence of hard pulses: n/2 -1/2Av + 7112 on resonance with one of the methyl signals.

4a: hellgelbes Pulver. Ausbeute: 67%, Schmp. 1 0 4 T (Zers.);4b: hellgelbesPulver. Ausbeute: 44%, Schmp. 112°C (Zcrs.). 7: 0.5 g (0.75 mmol) 1 in 4 mL Toluol wrden mit 1.5 mL (15 mmol) Benzaldehyd versetzt und 9 11 bci 45°C geriihrt. Die gelb-braune Reaktionslosung wird unter vermindertem Druck zur Trockne eingeengt. Durch anschliefiende Saulenchromatographie an Kieselgel (-3 0 T , HexanjEther 9: 1) und nachfolgendc Entfernung Angebb Cheni 1994. 106 Nr 23/24 C VCH Verlagsgesellschajt mhH, I)-69451 Wernlrerm, 1994 0044-8249/94/2323-256S 3 10 00+ ZS/0

l] Eine Ubersicht iiber schalenformige Fullereneinheiten gibt: a) J. S. Siege], T.

The reactions of trialkylphosphane selenides tBu n iPr 3-n PSe (n = 3: 1a; n = 2: 1b; n = 1: 1c; n = 0: 1d) with iodine are studied with the help of heteronuclear NMR spectroscopy, vibrational spectroscopy, and X-ray crystal structure determinations. The reaction of 1a with one equivalent of iodine provides, after crystallization from dichloromethane/pentane, solid 2a, which consists of pairs of molecular adducts tBu 3 PSe-I-I, together with chains of alternating [(tBu 3 PSe) 2 I] + and I 3 -ions. The addition of iodine to 1b, 1c, and 1d in a 1:1 molar ratio furnishes ionic solids with the formulation [(tBu niPr 3-n PSe) 2 I] + [I 3 ] -(n = 2: 2b; n = 1: 2c; n = 0: 2d). Compounds 2a-2d exhibit supramolecular structures based on various kinds of weak Se···I and Se···Se interactions. In 2a, the uncharged molecules form dimers through Se···Se contacts, while the anions and cations assemble to form chains through linear P-Se···I anion contacts. The ionic compounds 2b and 2d consist of the same type of chains, although they are not isotypic to each other. The two independent formula units of 2c are topologically different; one forms cation-anion chains analogous to those of 2b and 2d, whereas the other forms cation chains through Se···Se contacts. Se···I contacts between the latter chains and triiodide anions are very long but seem to be structurally significant; for such contacts, at well above the sum of the van der Waals radii, we propose

No abstract

No abstract