30651-68-4Relevant articles and documents
A frustrated-Lewis-pair approach to catalytic reduction of alkynes to cis-alkenes
Chernichenko, Konstantin,Madarasz, Adam,Papai, Imre,Nieger, Martin,Leskelae, Markku,Repo, Timo
, p. 718 - 723 (2013/08/23)
Frustrated Lewis pairs are compounds containing both Lewis acidic and Lewis basic moieties, where the formation of an adduct is prevented by steric hindrance. They are therefore highly reactive, and have been shown to be capable of heterolysis of molecular hydrogen, a property that has led to their use in hydrogenation reactions of polarized multiple bonds. Here, we describe a general approach to the hydrogenation of alkynes to cis-alkenes under mild conditions using the unique ansa-aminohydroborane as a catalyst. Our approach combines several reactions as the elementary steps of the catalytic cycle: hydroboration (substrate binding), heterolytic hydrogen splitting (typical frustrated-Lewis-pair reactivity) and facile intramolecular protodeborylation (product release). The mechanism is verified by experimental and computational studies.
Catalytic homocoupling of aryl, alkenyl, and alkynyl halides with Ni(II)-complexes and zirconocene dichloride
Peng, Jianbiao,Liu, Xiang,Kishi, Yoshito
experimental part, p. 2172 - 2175 (2011/05/05)
A new catalytic system (cat. (H)2Phen(Me)2· NiCl2 or (MeO)2Dipyr(H)2·NiCl 2, cat. Zr(cp)2Cl2, 2 equiv Mn, and 2 equiv LiCl) has been developed to facilitate the homocoupling of a wide range of aryl, alkenyl, and alkynyl halides.
Ni-catalyzed Si-B addition to 1,3-dienes: Disproportionation in lieu of silaboration
Gerdin, Martin,Moberg, Christina
, p. 2929 - 2932 (2007/10/03)
Upon attempted silaboration of acyclic 1- and 1,4-substituted 1,3-dienes, a new disproportionation reaction was discovered, yielding 1:1 mixtures of allylsilanes and dienylboranes. It was demonstrated that, as a key step in this new catalytic process, hyd
STRICTLY REGIO-CONTROLLED METHOD FOR α-ALKENYLATION OF CYCLIC KETONES VIA PALLADIUM-CATALYZED CROSS COUPLING
Negishi, Ei-ichi,Owczarczyk, Zbyslaw R.,Swanson, Douglas R.
, p. 4453 - 4456 (2007/10/02)
Cyclic α-iodoenones and α-triflyloxyenones, but not α-bromoenones, smoothly react with alkenylzinc and related derivatives in the presence of a catalytic amount of a palladium-phosphine complex, such as Pd(PPh3)4 or Cl2Pd(PPh3)2 treated with n-BuLi (2 equiv), to give α-alkenylenones which can be conjugatively reduced to the corresponding α-alkenyl ketones with complete retention of both enone regiochemistry and alkenyl stereochemistry.
REDUCTIVE DIMERIZATION OF VINYL HALIDES IN AN Ni/Pb/Al THREE METAL REDOX SYSTEM. A FACILE ACCESS TO TERPHENYL DERIVATIVES
Tanaka, Hideo,Kosaka, Atsuko,Yamashita, Shiro,Morisaki, Kazuo,Torii, Sigeru
, p. 1261 - 1264 (2007/10/02)
A novel three metal redox system, NiCl2(bpy)/PbBr2/Al, is found to be potent in the reductive coupling of vinyl halides, affording 1,4-biaryl-1,3-butadienes, precursors of terphenyl derivatives.
Stereoselective Synthesis of (E)-, (E,Z)-, and (E,E)-Conjugated Dienes via Alkylation of 3-Sulfolenes as the Key Step
Yamada, Sachiko,Ohsawa, Hideto,Suzuki, Takayoshi,Takayama, Hiroaki
, p. 4934 - 4940 (2007/10/02)
A new stereoselective method is presented for synthesizing (E)-, (E,Z)-, and (E,E)-conjugated dienes via alkylation of 3-sulfolenes as the key step.Direct alkylation of 3-sulfolene at the 2-position proceeds with good yields when labile sulfolene α-carbanion is generated in the presence of alkyl iodides in THF-HMPA solution at -78 deg C.Alkylation of 2-alkyl-3-sulfolenes gives trans-2,5-dialkyl-3-sulfolenes with 100percent regioselectivity and more than 90percent stereoselectivity.Desulfonylation of trans-3,5-disubstituted 3-sulfolenes is examined in detail, and the conditions to give stereoselectively the corresponding (E,Z)-and (E,E)-conjugated dienes are found.Applying the method, three insect pheromones, (E)-9,11-dodecadien-1-yl acetate, a sex pheromone of the red bollworm moth, (E,E)-8,10-dodecadien-1-ol, a sex pheromone of the codling moth, and (E,E)-11,13-hexadecadienal, a sex pheromone of the cabbage webworm, are easily synthesized by starting with 3-sulfolene with nearly 100percent stereoselectivity.Synthesis of cis-3,4,5-trisubstituted cyclohexenes using 2-substituted 3-sulfolenes as the diene synthons is also described.
STEREOSELECTIVE SYNTHESIS OF (E)-, (E,Z)- AND (E,E)-CONJUGATED DIENES VIA ALKYLATION OF 3-SULFOLENES AS KEY STEP
Yamada, Sachiko,Ohsawa, Hideto,Suzuki, Takayoshi,Takayama, Hiroaki
, p. 1003 - 1006 (2007/10/02)
Stereoselective method for synthesizing (E)-, (E,Z)- and (E,E)-conjugated dienes via alkylation of 3-sulfolenes as key step is developed.Sex pheromones with (E)- and (E,E)-conjugated diene structures are synthesized with exclusively high stereoselectivity by applying the method.
The Reaction of Alkenylboranes with Palladium Acetate. Stereoselective Synthesis of Olefinic Derivatives
Yatagai, Hidetaka
, p. 1670 - 1676 (2007/10/02)
The reactions of alkenylboranes with palladium acetate were investigated.Alkenyldialkylboranes, derived from terminal alkynes, underwent intramolecular migration reaction in the presence of an equimolar amount of palladium acetate and triethylamine to give (E)-olefins.On the other hand, under the same conditions as above or even in the presence of catalytic amounts of palladium acetate, alkenyldialkylboranes derived from internal alkynes underwent protonolysis reaction to produce (Z)-olefins.An alkenylpalladium intermediate which was presumably involved in the latter reaction was trapped by allylic chloride to give 1,4-dienes.
Stereospecific Synthesis of 1,4-Dienes by Cross-Coupling of Allyl Halides with Alkenylcopper Intermediates from Alkenyldialkylboranes
Brown, Herbert C.,Campbell, James B.
, p. 550 - 552 (2007/10/02)
Alkenylcopper intermediates, generated from alkenyldialkylborane derivatives of 9-borabicyclononane (9-BBN) and dicyclohexylborane (DCB), undergo stereospecific cross-coupling with allylic halides to yield stereodefined 1,4-dienes.
