Allylation molar ratio

Reportedly, OjoCdiaHylbispheaol A is an attractive comonomer for bismaleimides because the corresponding copolymer is tough and temperature resistant (41). Toughness, however, is a function of the BMI—diaHylbisphenol A ratio employed. In one study optimized toughness properties were achieved when BMI and diaHylbisphenol were employed at a close to 2 1 molar ratio (42). In Table 9, the mechanical properties of BMI—bis(3-allyl-4-hydroxyphenyl)-7 -diisopropylbenzene resias are provided, showiag optimized properties for the 60/40 BMI—diaHylbisphenol composition. The 0,(9 diaHylbisphenol A is commercially available under the trademark Matrimide 5292. Another bisaHylphenyl compound is available from SheH Chemical Company/Technochemie under the trademark COMPIMIDE 121. 

It has been pointed out earlier that the anti/syn ratio of ethyl bicyclo[4.1,0]heptane-7-carboxylate, which arises from cyclohexene and ethyl diazoacetate, in the presence of Cul P(OMe)3 depends on the concentration of the catalyst57). Doyle reported, however, that for most combinations of alkene and catalyst (see Tables 2 and 7) neither concentration of the catalyst (G.5-4.0 mol- %) nor the rate of addition of the diazo ester nor the molar ratio of olefin to diazo ester affected the stereoselectivity. Thus, cyclopropanation of cyclohexene in the presence of copper catalysts seems to be a particular case, and it has been stated that the most appreciable variations of the anti/syn ratio occur in the presence of air, when allylic oxidation of cyclohexene becomes a competing process S9). As the yields for cyclohexene cyclopropanation with copper catalysts [except Cu(OTf)2] are low (Table 2), such variations in stereoselectivity are not very significant in terms of absolute yields anyway. 

Basset and co-workers (91) found that amino olefins such as allyl amine and the /V.N-dimethyl derivative failed to undergo metathesis, but that unsaturated quaternary ammonium salts were active at 25°C with zero-valent tungsten and molybdenum catalysts when activated with molecular oxygen. Molar ratios of olefin/(mesitylene)W(CO)3/C2H5AlCl2/02 and olefin/Mo(NO)2Cl2[P(Ph)3]/C2H5AlCl2 were 20/1/24/80 and 20/1/24, respectively. Yields were in the 8-23% range. 

Akashi and coworkers prepared small platinum nanoparticles by ethanol reduction of PtCl in the presence of various vinyl polymers with amide side chains [49]. These authors studied the effects of molecular weight and molar ratio [monomeric unit]/[Pt] on the particle sizes and size distributions by electron microscopy, and in some cases by the dispersion stability of the Pt colloids. The hydrogenation in aqueous phase of allyl alcohol was used as a model reaction to examine the change in catalytic activity of polymer-stabilized Pt colloids upon addition of Na2S04 to the reaction solution. The catalytic tests were performed in water or in Na2S04 aqueous solution at 25 °C under atmospheric pressure of... 

Allylic bromination of 235 with excess CuBr and PhCCb-f-Bu (1 1 molar ratio) gives the separable allylic bromides 236 and 237 with 62% and 15% yield, respectively. Further treating the allylic bromide 236 with CuBr in CH3CN at 50° C leads to a mixture of 236 and 237, from which 25% of 236 and 69% of 237 can be separated. 

Addition of perfluoroalkyl iodides to allyl chloride unexpectedly afforded polyfluori-nated alkenes RpCH2CH=CH2 aside from the expected adduct RfCH2CH(I)CH2C1. The ratio of these two products increased with increasing molar ratio of the reagents and temperature. A mechanistic rationale has been offered. ... 

The ligand (S)-N-methylprolinol was used in a 2 1 molar ratio to the Mo02(acac)2 catalyst (1 mol % on the allylic alcohol (43) in the epoxidation of 3-methyl-2-buten-l-ol (43) with cumene hydroperoxide in cyclohexane solvent. 

The reaction of allylmagnesium chloride with methylaluminium dichloride affords, after workup of the reaction mixture and recrystalUzation from THF, a rather unexpected compound (7), which, according to its crystal-strucmre determination, appears to consist of [(allyl)2Mg3Cl3(THF)6]+ cations and [(allyl)4Mg] anions in a 2 1 molar ratio (Figure 8). ... 

In 1989, Isobe and coworkers reported on an organometallic polyoxometalate cluster (Rhcp )4V60i9] (cp = r/2-C4Me5) that catalyzes the oxidation of cyclohexene with TBHP as oxidant to give mainly allylic oxidation products (l-tm-butylperoxycyclohex-2-ene 42% and cyclohex-2-en-l-one 21%) and only httle epoxide (15%) (equation 62)432. The yield of 1-tm-butylperoxy cyclohex-2-ene increased with decreasing molar ratio of cyclohexene to TBHP, while the yield of cyclohex-2-en-l-one has a maximum at the ratio of 0.2. 

Figure 7.6 The dependence of propylene oxidation product yields on molar ratio C3H6 H202. T = 160°C 20% H202 vc3hs = 800ml/h t= 1.86s (1 propylene oxide 2 propionic aldehyde 3 allyl alcohol 4 acetone and 5 total propylene conversion).

Hay and co-workers reported that the Mn increased linearly with conversion at a molar ratio of 1 2. However, at high ratios of n-BuLi to TMEDA, the initiator became only 50% efficient. This finding is rather surprising as the addition of TMEDA to alkyllithium compounds enhanced the rate of the polymerization and without TMEDA, at Hay s polymerization temperature, no polymerization of the 1,3-butadiene took place. The explanation advanced by these authors was that the allylic lithium complex of polybutadiene is complexed with two TMEDA molecules and that complex 11 is the propagating species. 

Nevertheless, a few years ago, Kennedy 66 69) developed a method yielding co-functional polymers by cationic polymerization of vinyl monomers. The principle of the socalled inifer method is to kinetically favor transfer to the initiating species with respect to all other kinds of transfer reactions (especially the transfer to monomer). A typical initiating system is composed of an allyl or benzyl halide and boron trichloride BCl3. This mixture behaves like an alkenium tetrachloro-borate and readily initiates the polymerization of monomers such as isobutene or a-methylstyrene. The efficiency of the halide as a transfer agent depends on the lability of the C—Cl bond and on the molar ratio [RC1]/[BC13],... 

Equation 24 describes the Ni(0)-catalyzed addition of HCN to butadiene, which leads to 3-pentenenitrile together with its allylic isomer 2-methyl-3-butenenitrile (1.5 1 molar ratio). The branched allylic isomer, however, progressively isomerizes to the linear 3-pentenenitrile. 

Reduction of tertiary, allylic, and benzylic halides. NaCNBH, and ZnCI. in a 2 1 molar ratio in ether reduce these halides selectively in —70-90% yield in the presence of primary, secondary, vinyl, and aryl halides. I hc selectivity is comparable to that of lithium 9,9-di-/i-butyl-9-borabicyclol3.3.l nonate, the ate complex obtained by reaction of n-butyllithium with 9-BBN. ... 

A chiral complex of (1), L1A1H4, and A/-ethylaniline (molar ratio, 1 1 2) reduces aryl alkyl ketones to optically active alcohols in high ee. a, -Unsaturated ketones are reduced enantioselectively to afford optically active (S)-allylic alcohols with 80-98% ee. An intermediate in an anthracyclinone synthesis is prepared in 92% ee by the enantioselective reduction of a cyclic a,p-unsaturated ketone (eq 2). ... 

Nozaki and Yamamoto reported a novel method for regiospecific isomerization of epoxides to allylic alcohols based on diethylaluminum 2,2,6,6-tetramethylpiperidide (DATMP) which can be prepared in situ from Et2AlCl and lithium 2,2,6,6-tetramethylpiperidide (LiTMP) (molar ratio 1 1) in benzene at 0 °C for 30 min [119], Reaction of DATMP (4 equiv.) with ( )-cyclododecene oxide in benzene at 0 °C for 3 h produced ( )-2-cyclododecen-l-ol in 90 % yield. Interestingly, the reaction of diepoxide 121, a useful synthetic intermediate in the preparation of Cig-Cecropia juvenile hormone, with DATMP furnished the triol 122 in 41 % yield (Sch. 83). 

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