I Cinnamaldehyde

The kinetics and products of the reactions of tra i-cinnamaldehyde with OH, O3, and NO3 were studied by Smith et al. (1996) The motivation for the work was the structural relationship between this compound and commercially unavailable ring-opened Cio-dicarbonyls formed in significant yields from the OH-initiated oxidation of naphthalene. The following rate coefficients were obtained at 296 2 K, using relative rate methods A (OH) = (4.8 1.4) x 10" cm molecule" s" (placed on an... 

When cinnamaldehyde, succinic acid and acetic anhydride are heated in the presence of litharge (PbO), the aldehyde and the succinic acid condense to give the dicarboxylic acid (I), which undergoes decarboxylation to give the pale yellow crystalline 1,8-diphenyloctatetrene (II), Kuhn has shown that as the... 

Maleic anhydride is a convenient dienophile because of its rapid reaction with most dienes as well as its stability and ease in handling (although it is poisonous). The diene for this reaction, 1,4-diphenyl-1,3-butadiene, is readily prepared by the Wittig reaction with benzyltriphenylphosphonium chloride and cinnamaldehyde (Chapter 11, Section I). 

Dimethylamino)-cinnamaldehyde - hydrochloric acid -I- indole derivatives... 

CHROMIUM TRIOXIDE-PYRIDINE COMPLEX, preparation in situ, 55, 84 Chrysene, 58,15, 16 fzans-Cinnamaldehyde, 57, 85 Cinnamaldehyde dimethylacetal, 57, 84 Cinnamyl alcohol, 56,105 58, 9 2-Cinnamylthio-2-thiazoline, 56, 82 Citric acid, 58,43 Citronellal, 58, 107, 112 Cleavage of methyl ethers with iodotri-methylsilane, 59, 35 Cobalt(II) acetylacetonate, 57, 13 Conjugate addition of aryl aldehydes, 59, 53 Copper (I) bromide, 58, 52, 54, 56 59,123 COPPER CATALYZED ARYLATION OF /3-DlCARBONYL COMPOUNDS, 58, 52 Copper (I) chloride, 57, 34 Copper (II) chloride, 56, 10 Copper(I) iodide, 55, 105, 123, 124 Copper(I) oxide, 59, 206 Copper(ll) oxide, 56, 10 Copper salts of carboxylic acids, 59, 127 Copper(l) thiophenoxide, 55, 123 59, 210 Copper(l) trifluoromethanesulfonate, 59, 202... 

It is known that benzenediazonium-2-carboxylate decomposes to give benzyne via the zwitter-ion (128) 161>. We therefore checked that benzyne is involved in our reactions by carrying out reactions with cinnamaldehyde using benzyne generated from benzothiadiazole-1,1-dioxide 162), diphenyhodonium-2-carboxylate i 3,164)( weil as fr0m anthranilic acid165). Flavene was isolated from each reaction and hence our reactions do involve aiynes and are not arynoid 13 8). 

We recently reported a modified Meerwein-Ponndorf-Verley reduction in which low-boiling alcohols such as EtOH and w-PrOH, but preferably i-PrOH, were used at temperatures near 225 °C in the absence of aluminum alkoxides [42]. The carbonyl moiety of an olefinic aldehyde such as cinnamaldehyde was reduced selectively to the alcohol without the carbon-carbon double bond being affected (Scheme 2.7). Since base was not present, aldol and Claisen-Schmidt condensations were avoided. 

In 1998, Carreira reported that a catalyst formed from Tol-BINAP, Cu(OTf)2, and 2 equiv of Bu4N+ Ph3SiF2 (TBAT), a soluble fluoride source, was extremely effective in mediating the aldol reaction between a silyldienolate and aromatic or vinyl aldehydes (254). Although initially formulated as a Cu(II) catalyst, subsequent evidence has shown that the active catalyst is a Cu(I) phosphine complex. By using only 2 mol% of the complex, excellent yields and enantioselectivities are observed with a range of aromatic aldehydes (93-95% ee, 86-98% yield), along with some enals (cinnamaldehyde provided the aldol adduct in 83% yield and 85% ee), Eq. 221. 

It is to be mentioned that water-soluble phosphine complexes of rhodium(I), such as [RhCl(TPPMS)3], [RhCl(TPPTS)3], [RhCl(PTA)3], either preformed, or prepared in situ, catalyze the hydrogenation of unsaturated aldehydes at the C=C bond [187, 204, 205]. As an example, at 80 °C and 20 bar H2, in 0.3-3 h cinnamaldehyde and crotonaldehyde were hydrogenated to the corresponding saturated aldehydes with 93 % and 90 % conversion, accompanied with 95.7 % and 95 % selectivity, respectively. Using a water/toluene mixture as reaction medium allowed recycling of the catalyst in the aqueous phase with no loss of activity. 

Another a, i-unsaturated aldehyde analyzed is cinnamaldehyde. Its liquid-phase hydrogenation has been studied in our research group [20, 51, 94], using Pt, Ni and Cu-based tin-modified hi- and organobimetaUic catalysts (in all cases with Si02 as support). The catalytic results obtained showed that in aU cases there was a marked promoting effect of Sn on the selectivity to cinnamic alcohol (UOL). The specific modification of the monometallic systems due to Sn addition from the application of SOMC/M markedly increases the selectivity to UOL, especially in the case of Ni, where it goes from zero selectivity for the monometallic to 25% for the NiSn catalyst. Pt-based systems modified by Sn yield the best Suol values. 

There are some cases where both types of photocycloaddition take place. For example, cinnamaldehyde and crotonaldehyde yield, upon irradiation with 2-methyl-2-butene, both the oxetane and the cyclobutane products.26 In marked contrast, mesityl oxide, as similar as it would appear to be to crotonaldehyde (Table I), is stable to irradiation in the presence of both isobutylene and isopropanol.37,74 These differences in reactivity of a,/9-unsaturated carbonyl compounds have been attributed to conformational (that is, s-cis or s-trans) differences.74... 

Carbomethoxybenzaldehyde, 100 Carbon disulfide, 57 Chlorine, 24 Chloroacetamide, 22 Chloroacetonitrile, 22 Chlorobenzene, 96 lra i-2-CHLOROCYCLOPENTANOL, 24 2-Chloroethyl benzoate, 11 Chloromethylation, 68 1-Chloromethylnaphthalene, 67, 68 Chlorourea, see Monochlorourea Choline, chloride benzoate, 10 Choline, iodide benzoate, 10 Cinnamaldehyde, 75, 77 Cleavage of tetrahydrofuran, 27, 33 Condensation, of aniline and triphenyl carbinol, 5... 

Hydrogenation of r/wu-cinnamaldehyde (Figure 14 I Ri=H, R2=Ph) to phenylpropanol (IV Ri=H, R2=Ph) catalysed by Ru/tppms and Ru/tppts proceeds via two different routes in an aqueous/organic two phase system.492 With HRuCl(CO)(tppms)3 the reaction proceeds exclusively via the hydro-cinnamaldehyde III whereas with HRuCl(CO)(tppts)3 both II and III are involved (Figure 14, Ri=H, R2=Ph) 492... 

The structure of the reactive ternary complex composed of the enzyme NAD+, and 4-bromobenzyl alcohol was solved at 2.9-A resolution.14 This was possible because there is a favorable equilibrium between this complex and the enzyme-bound ternary complex reaction product of NADH and 4-bromo-benzaldehyde. The structure of the unreactive product-like complex composed of the enzyme, the coenzyme analogue H2NADH (i.e., NAD+ in which the nicotinamide ring has been reduced to 1,4,5,6-tetrahydronicotinamide), and trans-4- (N, A-dimethylamino)-cinnamaldehyde (DACA) was also solved at the same resolution.18... 

Iersel ML, Ploemen JP, Struik I, van Amersfoort C, Keyzer AE, Schefferlie JG, van Bladeren PJ. 1996. Inhibition of glutathione S-transferase activity in human melanoma cells by alpha,beta-unsaturated carbonyl derivatives. Effects of acrolein, cinnamaldehyde, citral, crotonaldehyde, curcumin, ethacrynic acid, and trans-2-hexenal. Chem Biol Interact 102 117-132. 

Cinnamic acid, starch ester, I, 303 Cinnamaldehyde, phytochemical reduction of, IV, 79, 91 Cinnamyl alcohol, IV, 91 phytochemical reduction of, IV, 92 Citraconic acid, IV, 327 Citral, phytochemical reduction of, IV, 79... 

---