Generation of (.eta.5-cyclopentadienyl)dicarbonyliron carbene complexes via protonation of the corresponding alkenyl complexes

Fe Organoiron Compounds Part B13

“…C s H s CH=CH 2 , and C s H s C(CH 3 )=CH 2 [174], see aLso [176], whiLe 2-methyLpent-1-ene, (Z)-n-dec-5-ene, 4-methyLcycLohexene, cis-cycLooctene, and cis-cycLododecene faiLed to give detectabLe amounts of cycLopropanes upon reaction with FpC(CH 3 )=CH 2 . Thus, dimethyLcycLopropanes are obtained from n-dec-1-ene, isobutene, .…”

“…Thus, dimethyLcycLopropanes are obtained from n-dec-1-ene, isobutene, . Treatment of FpC(CH 3 )=CH 2 with HBF 4 in ether at -23°C [176,201] or -30°C [174], see aLso [177,198], or with CF 3 S0 3 H in ether at -78°C [201] in the absence of aLkenes [201]. With respect to stereochemicaL behavior, the reactions of FpCH=CH 2 with cis-cycLooctene and C s H s C(CH 3 )=CH 2 proceed with syn-seLectivity.…”

“…On the basis of all these results the cyclopropanation reactions are assumed to proceed via the carbene derivatives [Fp=C(R1)CH a ]X. Intramolecular cyclopropanation with formation of norcarane takes place by treatment of FpCH=CH(CH2)aCH=CH2 in CH2C~ with HBF 4 at -50"C for 1 hand then with aqueous NaHCO a [174], see also [198,199], or of FpCH(SC6Hs)(CH2)4CH=CH2 with [0(CH a h]BF 4 in CH 2 Cl 2 [199].…”

“…Comp. Formation of the compound by treatment of FpCl with a THF solution of CH 2 =CHMgCl (20% yield) [9), treatment of Fpl with CH 2 =CHMgX (X = halogen) or LiCH=CH 2 (25 to 40% yield) [174], see also [198), or from [Fp(CH 2 =CH 2 )) + and CH 2 =CHMgCl (25% yield) [120) is briefly mentioned. 83° (dec.) [70], 80° (dec.) [16] lH NMR: 4.87 (CsH s ) ' yeLLow oiL [91], air-sensitive [149], mixture of two isomers ( ~ 1 : 1) [91]; no information about the geometry in [ [40], see also [15] red oil [193] lH [193,201], other bands 3585 [193), 3685 [201) mass spectrum: [M)+ [193,201) according to [91) geometry not given [57,91] [190] deep orange oil [ [105,106] amber oil [195] 1H NMR (CDCl [41,99,114], (40%) [80], (30%) [42] properties and remarks amber oiL [6], yeLLow oiL [32], decomposes at ~65° [198] prepared from [Fp=C(SC6Hs)CH3]CF3S03 and lithium divinylcuprate [198] ( [44,148], see also [62] supplement *176 FpCH=C=O VI [192] 178 FpCH(SCsHs)(CH2)4CH=CH2 1 [199] ' 110 CsHsFe(COhCH=CH2 (Table 5, No.…”

A Series of Vinylidene‐, Vinyl‐, Carbene‐ and Carbyneruthenium(II) Complexes with [Ru(PCy3)2] and [Ru(PiPr3)2] as Molecular Building Blocks

“…Casey [21] and Helquist [22] et al showed already in 1982 that neutral cyclopentadienyliron compounds with FeϪCRϭCH 2 as a linkage can be converted with HBF 4 into the corresponding cationic carbene derivatives. Similar transformations of neutral vinyl to monocationic carbene complexes by attack of an electrophile at the β-carbon atom of the vinyl ligand have since been carried by various research groups [23] including ours.…”