Cinnamaldehyde substituted

Diphenylbutadiene has been obtained from phenylacetic acid and cinnamaldehyde with lead oxide, by the dehydrogenation of l,4-diphenyl-2-butene with butyllithium, and by the coupling reaction of benzenediazonium chloride and cinnamyl-ideneacetic acid." The present method gives better yields than those previously reported, is adaptable to the preparation of a variety of substituted bistyryls, and is relatively easy to carry out. 

A substituted a,/3-unsaturated aldehyde, cinnamaldehyde, has been observed to undergo the same type of two-step 1,3-cycloaddition reaction with a cyclohexanone enamine as acrolein does, forming in this case a stereo-isomeric mixture of substituted bicycloaminoketones in excellent yield (29a,31a,31b). 

The procedure outlined is much quicker and simpler than previous methods Starting materials are readily available, and the preparation can be run on any scale in the length of a day. Because exclusion of a basic catalyst eliminates the Wolff-Kishner reduction of the cinnamalhydrazone, separation of the 5-phenylpyrazoline from cinnamalhydrazone, or of phenylcyclopropane from propenylbenzene, does not have to be effected. The present procedure can also be used to convert other ring-substituted cinnamaldehydes to the corresponding arylcyclo-propanes... 

Other excellent results have been reported by Kang et al. for the addition of ZnEt2 to aldehydes by using chiral cyclic amino thiol ligands depicted in Scheme 3.7. A total enantioselectivity was obtained when (lR,25)-l-phenyl-2-piperidinopropane-1-thiol was used as the ligand in the reactions of substituted benzaldehydes. However, -hexanal and traw -cinnamaldehyde could only be... 

We have shown that the direct arylation of acrolein toward the synthesis of cinnamaldehyde derivatives was an efficient procedure. Using the palladacycle 1 as catalyst, substituted aldehydes 3 were prepared with up to 87% isolated yield from condensed aiyl bromides (Scheme 21.1, Route 1) that was extended successfully to heteroaiyl bromides, like bromoquinolines (6). Alternatively, the acrolein diethyl acetal was used as olefin and a selective formation of the saturated ester 4 was attained under the same reaction conditions (Scheme 21.1, Route 2). The expected aldehydes 3 were, however, obtained from most of the aiyl halides used under modified conditions. It was shown that the addition of n-Bu4NOAc in the medium... 

In general, the results point to the edges and/or corners (small particles) favoring hydrogenation of the C=C bond whereas the planes (large particles) favor hydrogenation of the C=0 bond. This seems to be true for all compounds on Pt (see Table 2.6, lines 10-27, and 29-30) and for cinnamaldehyde on Ru and Rh (see Table 2.6, lines 33, 34, 37, and 38) however, citral on Ru did not exhibit this effect (see Table 2.6, lines 35 and 36), according to the authors statement. The reasons for this latter result are not clear. Why, for example should other alkyl-substituted a,P-unsaturated aldehydes exhibit this structure sensitivity and citral not Clearly, other factors are also at play. 

The condensation of the cinnamaldehyde derivative (18) with ethoxycarbonyl-pentyltriphenylphosphorane in DMF gave a mixture of tram-trans- and trans-cis-products.22 A general method to prepare l-substituted-m-9-alkenes (19), using a stereoselective Wittig reaction, has been described.23 2,2-Dimethyl-3-butenal (20)... 

Analogous to the use of chiral acetals one can employ chiral N,O-acetals, accessible from a, -unsatu-rated aldehydes and certain chiral amino alcohols, to prepare optically active -substituted aldehydes via subsequent Sn2 addition and hydrolysis. However, the situation is more complicated in this case, since the N,0-acetal center constitutes a new stereogenic center which has to be selectively established. The addition of organocopper compounds to a, -ethylenic oxazolidine derivatives prepared from unsaturated aldehydes and ephedrine was studied.70-78 The (diastereo) selectivities were rather low (<50% ee after hydrolysis) in most cases, the highest value being 80% ee in a single case.73 There is a strong solvent effect in these reactions, e.g. in the addition of lithium dimethylcuprate to the ( )-cinnamaldehyde-derived oxazolidine (70 Scheme 28) 73 the (fl)-aldehyde (71) is formed preferentially in polar solvents, while the (S)-enantiomer [ent-71) is the major product in nonpolar solvents like hexane. This approach was utilized in the preparation of citronellal (80% ee) from crotonaldehyde (40% overall yield).78... 

Silver acetate has a small catalytic effect on the alkene substitution reaction but 5 equiv. of the salt only give 140% of stilbene in the styrene phenylation, based upon palladium.15 The same reaction carried out at 80 C under 300 lbf in-2 (1 lbf in-2 = 6.89 kPa) of oxygen gives stilbene in 248% yield, based upon palladium.16 The best reoxidation reagent is f-butyl perbenzoate, which yields 10-14 turnovers of the palladium in the vinyl substitution of cinnamaldehyde and similar alkenes with benzene.17... 

The Ugi-4CR between (E)-cinnamaldehyde, amines, cyclohexyl isocyanide, and chloroacetic acid afforded N-substituted 2-amino-4-phenylbutenoic amides 55 which were cyclized in basic medium to N-substituted 2-(phenylethenyl)-4-oxoazetidine-2-carboxamides 57 via the highly delocalized intermediate anion 56 [47]. When R was an electron-poor aryl group, the f-lactam ring underwent a rearrangement to give succinimides 58 (Scheme 2.22) [48]. 

Besides chalcones, other types of a,p-unsaturated carbonyls affording five-membered S-heterocycles were cinnamaldehyde, 12, and the a,p-unsaturated methyl ketone 13 and phenyl ketones 14 and 15. However, another phenyl ketone, 16, substituted at the a position or tertiary butyl ketone 17 failed to yield S-heterocycles. 

The complexes 432 derived from the reaction of cinnamaldehyde with Ru-SH complexes 433 undergo [4+2] cycloaddition reactions with a range of electron-rich, electron-deficient, and strained dienophiles. The products are Ru complexes of di- or tri-substituted 3,4-dihydro-2/7-thiopyrans. Generally, the reaction shows high regioselectivity and good diastereoselectivity with a marked preference for the endo adducts (Scheme 139). Ethyl propynoate affords the 3,4-disubstituted-477-thiopyran <2006CEJ4821>. 

The complexes of zinc and cadmium with Schiff bases derived from salicylaldehyde and propan-2-olamine or 2-aminomethylpropanol have been reported,57 as well as their complexes with ethanolamine and propan-2-olamine.58,59 Zinc complexes of stoicheiometry ZnL2X2 have been obtained where L = benzoyl- and salicyl-hydra-zones of vanilline. furfural, and cinnamaldehyde. Zinc complexes of several substituted o-bydroxybutyrophenones and their oximes have been reported.60-62 Complexes of stoicheiometery ZnL2U have been reported where L = the a-nitroketonato-anion obtained from nitroacetone, 3,3-dimethyl-l-nitrobutan-2-one or 3-nitrocam-phor and L — bipyridyl or 1,10-phenanthroline.63... 

An alkoxy-substituted cinnamyl system 44 is transiently generated by the treatment of cinnamaldehyde 42 with lithiated trimethylethylenediamine 43, and this protected version of cinnamaldehyde undergoes carbolithiation with good diastereoselectivity in favour, like 32, of the syn product 45.30... 

In addition, the same authors showed that ,/ -unsaturated aldehydes 132 could act both as CO and alkene source and give the PK products 134 upon reaction with different alkynes (133) (Scheme 41). As part of their study, they performed a cross reaction of cinnamaldehyde and a substituted styrene with phenylacetylene, isolating two PK products coming from both alkenes. This is a proof for a decarbonylative-[2 + 2+1] reaction pathway [147]. 

The ortho-substituted isothiocyanates are valuable intermediates for the preparation of a variety of heterocyclic compounds for example, o-isp-thiocyanato-( )-cinnamaldehyde with sodio diethyl malonate undergoes facile cyclization to 3-formylquinoline-2(l//)-thione,9 which in turn may be used for the preparation of tricyclic9,10 and large ring heterocyclic compounds."... 

We (and in parallel Bode et al.) were pleased to find that the IMes-catalyzed conjugate umpolung of a,(j-unsaluralcd aldehydes has a broad scope (Burstein and Glorius 2004 Burstein et al. 2006 Schrader et al. 2007 Sohn et al. 2004 He and Bode 2005 Sohn and Bode 2005) (For related applications of NHC in organocatalysis, see Chow and Bode 2004 Reynolds et al. 2004 Chan and Scheidt 2005 Reynolds and Ro-vis 2005 Zeitler 2006 Nair et al. 2006a,b He et al. 2006 Fischer et al. 2006 Chiang et al. 2007 Philips et al. 2007 Maki et al. 2007). Under optimized conditions, a 1 1 mixture of cinnamaldehyde and the ben-zaldehyde derivative in THF was treated with IMes (prepared in situ from IMes HCl and an excess of KOtBu) and stirred at ambient temperature for 16 h (Table 1). A variety of differently substituted aromatic... 

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