Butadiene palladium-catalysed reactions

Further work on the palladium-catalysed reaction of butadiene with carbonyl compounds, which gives tetrahydropyrans, has been reported. The d-hydroxyaldehydes (237), obtained by the action of alkyl Grignard reagents on glutaraldehyde, form cyclic hemiacetals (238) which may be... 

Butadiene reacts with primary or secondary amines (/.e., R R NH) in the presence of [Pd(acac)2]+PPh3 to give 94% CH2=CH(CH2)3CH=CHCH2-NR R. Similar palladium-catalysed reactions of isoprene with diethyl-amine and isoprene with 3,3-dimethyldiaziridine, Me2CN(H)NH, have been reported. In the presence of traces of water, Pd(OAc)2+3.5 PPh3 catalyses reaction (22) the catalyst also isomerizes (23) to (22). ... 

Trialkylstannanes undergo palladium-catalysed regioselective addition to 1,3-butadienes, as shown in reaction 12269. 

Bessmertnykh A, Henin F, Muzart I (2005) Palladium-catalysed telomerization of butadiene with aldoses a convenient route to non-ionic surfactants based on controlled reactions. J Mol Catal A Chem 238 199-206... 

The synthesis of enantiomerically pure dienyl sulfoxides through palladium-catalysed coupling reactions has been reported [36,37]. An efficient Stille coupling process was used to synthesize both (lE E)- and (lZ,3 )-l-sulfinyl-l,3-butadienes through the use of stereodelined vinyl stannanes [36]. For example, coupling of the P-bromo-a,P-imsaturated sulfoxide (23) with vinylstannane (24) under palladiiun catalysis leads to the enantiomerically pure (l , 3 )-l-sulfinyl-l,3-butadiene (25) (Scheme 5.8) [36]. 

The synthesis of diazepam and related 1,4-benzodiazepines has been accomplished by means of a palladium-catalysed carbonylation reaction. Similarly, this reaction has been employed as the key step for the construction of benz-lactams, in syntheses of anthramycin and of the lycorine ring system. Palladium-mediated macroheterocyclization has been used in an impressive synthesis of indandenin-12-one in a remarkable 23.3% overall yield from butadiene monoepoxide. The key step provided the necessary 21-membered ring in nearly quantitative yield in a highly chemo-, regio-, and stereo-selective fashion (Scheme 41). ... 

The palladium(ii) acetylacetonate-tri phenyl phosphine catalysed reaction of butadiene with water and carbon dioxide in solvents such as t-butanol or acetone has been reported to give octa-2,7-dien-l-ol as the major product together with minor amounts of octa-l,7-dien-3-ol, 1,3,7-octatriene and octadienyl ethers. In contrast aqueous potassium tetrachloropalladate with excess diene leads to pale yellow solids which were polymeric. Decomposition of these complexes with dimethylglyoxime gave a mixture of 3-methyIbutenyl ethers, (Scheme 33). The use of (—)-2,2-dimethyl-4,5-bis(diphenylphosphinomethyl)-l,3-dioxolane (DIOP) as a chiral ligand... 

Pd(acac)8+PPh3+Et8Al -catalysed telomerization of butadiene with HZ [Z=RS02 or R0(CH8) 0 ] yields the corresponding product (24). [Pd(PPh3)4] catalyses reaction (23) similar palladium-catalysed additions of... 

Palladium complexes generated from the sulfonated ligand 5 (Table 2 R=Me, n=0,l,2) were also used to catalyse the telomerization of 1,3-butadiene with water108 and from the aminophosphines 83 (Table 5 R=Ph R =H,Me R"=Me,iPr n=2,3) with MeOH to give l-methoxy-2,7-octadiene in selectivities up to 78% at conversions ranging from 52 to 80%.232 Pd/83 (R=Ph R =H,Me R"=Me,iPr n=2,3) catalysts are more active but less selective in the latter reaction compared to their tppts counterparts.232 9... 

Some authors have proposed mechanisms based on bimetallic palladium species. Keim and colleagues, for instance, proposed a reaction mechanism for the telomerization of acetic acid with butadiene (Scheme 10), where the key intermediate is a bispalladium compound such as Pd2([i-1,2,3,6,7,8-r 6-octa-2,7-dien-l, 8-diyl)((j,-OAc)2] [65]. It was shown that these bimetallic compounds are able to catalyse telomerization in the presence of 1,3-butadiene, acetic acid and a phosphine ligand. 

Sasaki Y, Inoue Y, Hashimoto H (1976) Reaction of carbon dioxide with butadiene catalysed by palladium complexes. Synthesis of 2-ethylidenehept-5-en-4-olide. J Chem Soc, Chem Commun 605-606... 

CROSS-COUPLING REACTION OF ALKYL HALIDES WITH GRIGNARD REAGENTS IN THE PRESENCE OF 1,3-BUTADIENE CATALYSED BY NICKEL, PALLADIUM, OR COPPER... 

Trimethylsilyl esters are very moisture sensitive and so their preparation is best achieved by methods that avoid aqueous work-up such as reaction of the carboxylic acid with 6is(trimethylsilyl)acetamide (BSA) to give the trimethylsilyl ester [Scheme 6.109). Another mild method for preparing TMS esters that avoids aqueous work-up involves Pd-catalysed extrusion of butadiene from 4-(trimethylsilyl)but-2-enyl esters as discussed. Benzyl esters can be cleaved with ferf-butyldimethylsilane (Bu e2SiH) in the presence of palladium(Il) ace-... 

Co-addition and Co-oligomerisation.—Nickel and palladium catalysts are again much in evidence. The same 7r-tetramethylcyclobutadienenickel dichloride plus alkylaluminium halide mixed catalysts which have been investigated in relation to alkene oligomerisation (see above) catalyse coaddition of ethylene and propene. Kinetic results for this reaction are reported. Product analysis and distribution permit postulation of mechanisms of addition of butadiene and but-2-yne to give 4,5-dimethyl-1-... 

The nickel(o)-catalysed oligomerization of butadiene has been further studied. Cyclo-octa-1,5-diene is a major product in hydroxylic solvents, and a minor product in the presence of secondary amines." The oligomerization of butadiene in the presence of nickel(ii)acetylacetonate, triethylamine, alkyl cyanamides, and miscellaneous heterocycles has also been studied, and catalyst systems causing an almost quantitative conversion into trans,trans,trans-, cis,trans,trans-, or cis,cis,trans-cyclododeca-l,5,9-triene were found." The ability of some hydrides, trans-MHX-(PR3)2 (M = Ni or Pd), to act as catalysts for butadiene oligomerization has been found to depend upon the substituent, X, and the solvent the reactions of some cationic palladium hydrides with butadiene was also examined. Unlike other organo-cobalt catalyst systems, CoCUPPhjjj has been found to catalyse the dimerization... 

Palladium complexes catalyse similar reactions, usually under milder conditions than those required using nickel. Azelaic acid (nonanedioic acid), which is an intermediate in the synthesis of the speciality nylon 6,9, is obtained from butadiene via 1, 5-cyclo-octadiene. 

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