1128-65-0Relevant academic research and scientific papers
Non-dehydrative pinacol rearrangement using a Lewis acid-trialkyl orthoester combined system
Kita, Yasuyuki,Yoshida, Yutaka,Mihara, Sachiko,Furukawa, Akihiro,Higuchi, Kazuhiro,Fang, Dai-Fei,Fujioka, Hiromichi
, p. 14689 - 14704 (1998)
An efficient pinacol rearrangement mediated by trialkyl orthoformate has been developed. The reactions of various types of diols with a catalytic amount of a Lewis acid in the presence of an orthoester afforded the rearranged product in good yields via a cyclic orthoester intermediate. This combined system is applicable not only to cyclic and acyclic tri- and tetra- substituted diols but also to the diols having acid-sensitive acetals.
Multimetallic Ni- and Pd-Catalyzed Cross-Electrophile Coupling to Form Highly Substituted 1,3-Dienes
Olivares, Astrid M.,Weix, Daniel J.
supporting information, p. 2446 - 2449 (2018/02/28)
The synthesis of highly substituted 1,3-dienes from the coupling of vinyl bromides with vinyl triflates is reported for the first time. The coupling is catalyzed by a combination of (5,5′-bis(trifluoromethyl)-2,2′-bipyridine)NiBr2 and (1,3-bis(diphenylphosphino)propane)PdCl2 in the presence of a zinc reductant. This method affords tetra- and penta-substituted 1,3-dienes that would otherwise be difficult to access and tolerates electron-rich and -poor substituents, heterocycles, an aryl bromide, and a pinacol boronate ester. Mechanistically, the reaction appears to proceed by an unusual zinc-mediated transfer of a vinyl group between the nickel and palladium centers.
Renewable high-density spiro-fuels from lignocellulose-derived cyclic ketones
Xie, Junjian,Zhang, Xiangwen,Pan, Lun,Nie, Genkuo,Xiu-Tian-Feng,Liu, Qing,Wang, Peng,Li, Yafei,Zou, Ji-Jun
supporting information, p. 10303 - 10305 (2017/09/23)
Renewable high-density spiro-fuels are synthesized from lignocellulose-derived cyclic ketones for the first time, which show higher density, higher neat heat of combustion and lower freezing point compared with other biofuels synthesized from the same feedstock, and thus represent a new type of renewable high-density fuel attractive for practical applications.
Comparison of the catalytic activity of [(η5-C 5H5)Ru(2,2′-bipyridine)(L)]OTf versus [(η5-C5H5)Ru(6,6′-diamino-2,2′- bipyridine)(L)]OTf (L = labile ligand) in the hydrogenation of cyclohexanone. Evidence for the presence of a metal-ligand bifunctional mechanism under acidic conditions
Dimondo, Domenico,Thibault, Michelle E.,Britten, James,Schlaf, Marcel
, p. 6541 - 6554 (2013/12/04)
The two title complexes as well as the dimeric complex [Ru(II) (η5-C5H5)(6,6′-diamino-2,2′- bipyridine)]2(OTf)2 have been synthesized and characterized by NMR and single-crystal X-ray crystallography. The direct structural comparison of the 2,2′-bipyridine and 6,6′-diamino-2, 2′-bipyridine complexes suggests that the electronic and steric environments of the ruthenium centers in both complexes are essentially equivalent, providing for a unique opportunity to probe the influence of the noncoordinated amine substituent on the relative reactivity and catalytic activity of the complexes. Opposite to what would be anticipated on the basis of steric effects, the bulkier amine-substituted ligand results in a catalyst showing substantially higher activity in the hydrogenation of cyclohexanone in acidic medium, which is attributed to the operation of a metal-ligand bifunctional hydrogenation mechanism mediated by the amine substituents in their protonated form acting as proton shuttles.
Study of I-strain relief in the intermediate when forming spiro ketones from unsymmetrical cycloalkylidenecycloalkanes, their dibromides, and their pinacols
Sands
, p. 468 - 471 (2007/10/02)
Three unsymmetrical intercyclic olefins, their dibromides, and their pinacols were prepared, each so the two carbons involved at the functional group were part of a different sized ring. The pinacols were reacted with 25% sulfuric acid and with boron trif
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.
SYNTHESE STEREOSELECTIVE DE DIENES CONJUGUES A PARTIR D'ALCOOLS α-ALLENIQUES
Djahanbini, Dariouche,Cazes, Bernard,Gore, Jacques
, p. 3645 - 3656 (2007/10/02)
The reaction of a Grignard reagent with an α-allenic phosphate leads exclusively in every studied case to 1,3-dienes.A high stereoselectivity is observed for the formation of both double bonds; particularly, the organometallic species attacks preferentially in a trans direction from a group located on the terminal allenic carbon.In the case of the esters of secondary alcohols, it is more difficult to determine the factors which govern the stereochemistry of the other double bond.The Z configuration is then favoured in the reaction phosphate + RMgX but the E configuration is predominant in the reaction acetate + R2CuLi.
