80997-79-1Relevant academic research and scientific papers
Synthesis of η3-2-stannylmethylallylpalladium complexes and their destannylation leading to trimethylenemethane-palladium species
Watanabe, Saisuke,Ogoshi, Sensuke,Kakiuchi, Kiyomi,Kurosawa, Hideo
, p. 19 - 26 (1994)
η3-2-Stannylmethylallylpalladium chloride dimer 3-CH2C(CH2SnMe3)CH2)Cl>2 (1a) reacted with a neutral ligand L to form corresponding cationic complexes 3-CH2C(CH2SnMe3)CH2)L2>Cl (L=PPh3: 2a, 1/2 bipy: 5 (bipy=2,2'-bipyridyl)), which were characterized by 1H NMR at low temperature only for 2a and at room temperature for 5.On addition of Bu3SnCl the cationic complex 5 underwent stannyl group exchange equilibrium with 3-CH2C(CH2SnBu3)CH2) (bipy)>Cl.Addition of 2 equiv PPh3 and RCHO (R=Ph, CH2=CH) to 1a at room temperature afforded the cycloaddition products, methylenetetrahydrofurans, in good yields.The complex 1a reacted with PhCHO in the presence of bipy and dppe (dppe = 1,2-bis(diphenylphosphino)ethane) to give the aldehyde adduct complexes 3-CH2C(CH2CHPh(OSnMe3))CH2)L2>Cl (L=1/2 bipy, 1/2 dppe), which were characterized by 1H NMR.The possible generation and the reactivities of the trimethylenemethane-palladium complex intermediate are discussed in the light of these results.Key words: Palladium; Stannyl; Destannylation; Trimethylenemethane
A new Ru catalyst for alkene-alkyne coupling
Trost, Barry M.,Toste, F. Dean
, p. 7739 - 7743 (1999)
[CpRu(CH3CN3)]+PF6- proves to be an effective catalyst for an intermolecular Alder ene type reaction that provides considerable broadening of scope of the process.
Novel synthesis of methylenecyclobutanols and 4-methylenetetrahydrofurans from γ-oxide ylides
Okuma, Kentaro,Kamahori, Yoshihiro,Tsubakihara, Kimiko,Yoshihara, Kanami,Tanaka, Yuichiro,Shioji, Kosei
, p. 7355 - 7360 (2007/10/03)
The reaction of δ-halo-γ-oxide ylide, prepared from methylenetriphenylphosphorane and epichlorohydrin, with aldehydes afforded alkylidenecyclobutanols in moderate yields. The reaction initially proceeded through internal nucleophilic attack on δ-carbon of this ylide. Another novel approach toward the synthesis of 4-methylenetetrahydrofurans was achieved by the reaction of γ-oxide ylides with paraformaldehyde.
Tributyltin chloride-sodium cyanoborohydride mediated tandem radical cyclisation-reductive demethoxylation sequence
Srikrishna,Viswajanani,Yelamaggad
, p. 10479 - 10488 (2007/10/03)
Reaction of the bromoketals 3, 7a-g and 11 with tri-n-butyltin chloride and sodium cyanoborohydride in the presence of a catalytic amount of AIBN furnished the ethers 5, 8a-g and 13 via a tandem sequence comprising of a radical cyclisation reaction and tri-n-butylhalostannane and sodium cyanoborohydride mediated reductive demethoxylation of the resulting cyclic ketals.
3-Methylseleno-2-[methylselenomethyl]-propene valuable precursor of trimethylenemethane and trimethylenemethane dianion
Krief, Alain,Dumont, Willy
, p. 657 - 660 (2007/10/03)
3-Methylseleno-2-[methylselenomethyl]-propene proved to be a valuable precursor of 3-lithio-2-[methylselanomethyl]-propene and 3-lithio-2-[lithiomethyl]-propene. These have been reacted with various electrophiles and have in turn been successfully transfo
Tetrahydrofuran derivatives from epoxides via group transfer cyclization or reductive radical cyclization of organotellurium and organoselenium intermediates
Engman, Lars,Gupta, Vijay
, p. 157 - 173 (2007/10/03)
Monosubstituted epoxides were regiospecifically ring-opened from the sterically least hindered side by benzenetellurolate and benzeneselenolate reagents to afford aryl β-hydroxyalkyl tellurides and selenides, respectively. These materials were O-allylated by treatment with allylic bromides/sodium hydride in tetrahydrofuran and O-prop-2-ynylated when reacted with propargyl bromide/sodium hydride. On photolysis in benzene containing 40 mol % of hexabutylditin, the β-(allyloxy)alkyl aryl tellurides were found to undergo group transfer cyclization to afford 2-substituted 4-[(aryltelluro)methyl]tetrahydrofurans (cis/trans = 1/3-1/10). The aryl β-(prop-2-ynyloxy)alkyl tellurides similarly afforded 2-substituted 4-[(aryltelluro)methylene]tetrahydrofurans with an E/Z-ratio close to unity. The β-(allyloxy)alkyl aryl selenides and aryl β-(prop-2-ynyloxy)alkyl selenides failed to undergo group transfer cyclization. In the presence of tributyltin hydride and 2,2'-azobisisobutyronitrile, the former compounds were found to undergo reductive radical cyclization in high yields to afford 2-substituted 4-methyltetrahydrofurans (cis/trans = 1/3-1/10). Aryl β-(prop-2-ynyloxy)alkyl selenides similarly afforded 2-substituted 4-methylenetetrahydrofurans. 2-Alkoxy-2-(allyloxy)ethyl phenyl selenides, prepared by allyloxyselenenation of vinyl ethers, were found to undergo reductive radical cyclization to afford 2-alkoxy-4-methyltetrahydrofurans (cis/trans = 13-1/4). The preference for formation of trans-2,4-disubstituted tetrahydrofurans in the group transfer and reductive radical cyclizations was rationalized assuming a chairlike transition state with a preferred adoption of a pseudoequatorial position of the 2-substituent. By carrying out the reactions at lower temperatures (ambient or -45°C), using triethylborane as an initiator, it was possible to further increase the trans selectivity in the reductive cyclizations.
A novel and convenient synthesis of 2-aryl-4-methylenetetrahydrofurans from 2-(trimethylsiloxymethyl)allyltrimethylsilane and acetals
Oriyama,Ishiwata,Sano,Matsuda,Takahashi,Koga
, p. 5581 - 5584 (2007/10/03)
The reaction of acetals with 2-(trimethylsiloxymethyl)allyltrimethylsilane under the influence of the combined use of a catalytic amount of tin(II) halide and acetyl halide affords the corresponding 2-aryl-4-methylenetetrahydrofurans in good yields.
3-Methylenetetrahydrofurans and 3-Methylenepyrrolidines by Addition of 2-(Bromozincmethyl)-2-alkenyl Ethers or 2-(Chloromagnesiomethyl)-2-alkenyl Ethers to Aldehydes, Ketones and Imines followed by Pd(0)-Catalyzed Cyclization
Louw, Jaap van der,Baan, Juul L. van der,Stichter, Henk,Out, Gerardus J. J.,Kanter, Franciscus J. J. de,et al.
, p. 9877 - 9900 (2007/10/02)
Reaction of 2-(bromozincmethyl)-2-alkenyl ethers 1 or 2-(chloromagnesiomethyl)-2-alkenyl ethers 2 with aldehydes, ketones and imines affords the addition products 4 and 8, which undergo Pd(0)-catalyzed cyclization to the 3-methylenetetrahydrofurans 6 (Rs
3-METHYLENETETRAHYDROFURANS AND 3-METHYLENEPYRROLIDINES BY ADDITION OF 2-BROMOZINCMETHYL-2-PROPENYL ETHERS TO ALDEHYDES, KETONES AND IMINES FOLLOWED BY Pd(0)-CATALYZED CYCLIZATION
Louw, J. van der,Baan, J. L. van der,Stichter, H.,Out, G. J. J.,Bickelhaupt, F.,Klumpp, G. W.
, p. 3579 - 3580 (2007/10/02)
Reaction of 2-(benzyloxymethyl)- and 2-(phenoxymethyl)allylzinc bromides 1a and 1b with aldehydes, ketones and imines afforded the addition products 3 and 6, which underwent Pd(0)-catalyzed cyclization to the tetrahydrofurans 4 and pyrrolidines 7.
