Toluenes cyclohexyl

The crucial experiment suggesting that the H2 molecule might act as a dihapto ligand to transition metals was the dramatic observation that toluene solutions of the deep purple coordinatively unsaturated 16-electron complexes [Mo(CO)3(PCy3)2] and [W(CO)3-(PCy3)2l (where Cy = cyclohexyl) react readily and cleanly with Ha (I atm) at low temperatures to precipitate yellow crystals of [M(CO)3H2(PCy3)2] in 85-95% yield. The... 

Addition of organolithiutn reagents in toluene to A-cyclohexyl enimines in the presence of chiral nonracemic diethers or diamines (1.2-2,4 equiv) gives, after hydrolysis, //-substituted aldehydes2. It is important to note that these reactions do not occur in the absence of the chiral additive which can be recovered quantitatively for reuse without loss of enantiomeric purity6. 

Fig. 21 Microwave-promoted multicomponent synthesis of polysubstituted thiophenes on solid-phase. Reagents and conditions a RCOCH2R (R = H, Me, Et, Bn R = Me, i-Bu, i-Pn, Ph, Bn, cyclohexyl), Ss, DBU, toluene, MW 120 °C, 20 min, closed vessel, 100% b R"COCl (R" = Me, Pr, Ph or COOMe), diisopropylethylamine, toluene, MW 100 °C, 10 min, closed vessel c TEA, H2O, CH2CI2, rt, 2h...

The N-3 position of uracil also can be modified with carbodiimide reagents. In particular, the water-soluble carbodiimide CMC [l-cyclohexyl-3-(2-morpholinoethyl) carbodiimide, as the metho p-toluene sulfonate salt] can react with the N-3 nitrogen at pH 8 to give an unstable, charged adduct. The derivative is reversible at pH 10.5, regenerating the original nucleic acid base (Figure 1.47). Cytosine is unreactive in this process. 

Conducted in toluene. BHA = 2,6-di-ter -butyl-4-methoxyphenyl Naph = naphthyl Cy = cyclohexyl Ar = 2,6-diisopropylphenyl ent = enantio. Molar equivalents to the amounts of organolithium. 

Conducted in toluene. Boc = tert-butoxycarbonyl Cy = cyclohexyl TIPS = Misopropylsilyl. In the presence of trimethylsilyl chloride. 

The first reactions concerned (Simons and Archer, 27) alkylation of benzene with propylene to form isopropylbenzene, with isobutene to form f-butylbenzene and di-f-butylbenzene, and trimethylethylene to form amylbenzene. Later on (Simons and Archer, 28) studied these and other reactions in more detail and showed that high yields could be obtained and that the product was not contaminated with tars or other obnoxious impurities. It was shown that the products obtained with trimethylethylene were mono- and di-f-amylbenzene, that phenyl-pentane resulted from the use of pentene-2, and that cyclohexene produced cyclohexylbenzene. Cinnamic acid reacted with benzene (Simons and Archer, 29) to form /3-phenylpropionic acid and allyl benzene reacted with benzene to form 1,2-diphenylpropane. It is interesting to note that although allyl alcohol reacted with benzene to form 1,2-diphenylpropane, the intermediate in the reaction, allylbenzene, was isolated and identified. This shows that in this case the hydroxyl reacted at a more rapid rate than the double bond. Both di- and triisobutylene reacted with phenol (Simons and Archer, 30) at 0°, when using hydrogen fluoride containing only relatively small quantities of water, to form f-butyl-benzene, but diisobutylene with 70% hydrogen fluoride produced p-f-octylphenol. Cyclohexene reacted with toluene to form cyclohexyl-toluene and octene-1 rapidly reacted with toluene to form 2-octyltoluene (Simons and Basler, 31). 

Problem 11.38 Irradiation of an equimolar mixture of cyclohexane, toluene and Br in CCI4 gives almost exclusively benzyl bromide. A similar reaction with Clj gives mainly cyclohexyl chloride. Explain. ... 

Problem 14.55 Prepare the following ethers starting with benzene, toluene, phenol (C H OH), cyclohexanol, any aliphatic compound of three C s or less and any solvent or inorganic reagent a) dibenzyl ether, b) di-/i-butyl ether, (c) ethyl isopropyl ether, d) cyclohexyl methyl ether, (e) p-nitrophenyl ethyl ether, (/) divinyl ether (g) diphenyl ether. <... 

Relevant bond distances and angles of dinitrogen complexes whose X-ray structure has been determined are shown in Table 15. The complex [ Ni(PCy3)2 2N2] (Figure 1) is dimeric, with the N2 molecule coordinated end-on to the two nickel atoms. Each nickel atom is surrounded by four cyclohexyl groups of the phosphine ligands which give some steric protection.227 IR, 31P and HNMR spectra indicate that in toluene solutions of this complex the equilibrium shown in equation (60) operates.236... 

A good source of uncommon bases is tRNA. It provides substrates for studying the effect of base on the rate of hydrolysis. Baev et al. (62) showed that V2-dimethylguanylyl-(3 -5 )-cytidine-3 phosphate (G2m-pCp) was hydrolyzed much slower than the usual GpCp. Venkstern (63) reported that Tp was hydrolyzed very slowly. Naylor et al. (64) found that Cp was hydrolyzed with half the rate of CpU. The same group of workers introduced (64, 65) a chemical block on uridine and pseudo-uridine residues by reacting RNA with l-cyclohexyl-3-(2-morpho-liny]-(4)-ethyl)-carbodiimide metho-p-toluene sulfonate. The modification of the uridine residues completely blocked the action of venom exonuclease and also blocked the action of pancreatic RNase. 

When a toluene solution of a mixture of cyclotrisilane 34 and cyclohexyl isocyanate (or f-butyl isocyante) was heated at 70 °C, cyclic di- and trisiloxanes 37 and 38, i.e. the cyclic dimer and trimer of the silanone 36, were obtained together with the corresponding isonitrile RN=C. The formation of 37 as well as 38 was completely suppressed in the presence of hexamethylcyclotrisiloxane (19 D3) instead, quantitative conversion of 35 into 39, the formal insertion product of the silanone 36 into the Si—O bond of D3, occurred (Scheme 14). Since neither cyclodisiloxane 37 nor cyclotrisiloxane 38 reacted with D3 under the reaction conditions, the possibility that 37 or 38 is the precursor of 39 was ruled out. Whereas the oxidation of 35 with cyclohexyl and t-butyl isocyanates proceeded with exclusive formation of 37 and 38 (as the silicon-containing compounds) the reaction of 35 with phenyl isocyanate resulted in the formation of 37 in low yield. Furthermore, in this case the presence of D3 did not totally suppress the formation of 37. According to the authors, these results indicate that the oxidation of 35 with cyclohexyl and f-butyl isocyanates appears to use other reaction channels than that with phenyl isocyanate. 

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