19066-24-1Relevant articles and documents
Cross-coupling method of alkyl chloride and phenyl magnesium bromide
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Paragraph 0026; 0027; 0028, (2018/07/28)
The invention provides a cross-coupling method of an alkyl chloride and phenyl magnesium bromide, wherein a copper salt is used as a catalyst, the 2-methyltetrahydrofuran solution of phenyl magnesiumbromide is used as a coupling reagent, and the corss-coupling of the inactive secondary/tertiary alkyl chloride and the phenyl magnesium bromide is achieved. According to the present invention, the method has the high yield, does not require the addition of the ligand, is simple and easy to perform, and has important significance in the synthesis of complex molecules such as natural products, chiral drugs, and the like.
Redox-Active Esters in Fe-Catalyzed C-C Coupling
Toriyama, Fumihiko,Cornella, Josep,Wimmer, Laurin,Chen, Tie-Gen,Dixon, Darryl D.,Creech, Gardner,Baran, Phil S.
supporting information, p. 11132 - 11135 (2016/10/12)
Cross-couplings of alkyl halides and organometallic species based on single electron transfer using Ni and Fe catalyst systems have been studied extensively, and separately, for decades. Here we demonstrate the first couplings of redox-active esters (both isolated and derived in situ from carboxylic acids) with organozinc and organomagnesium species using an Fe-based catalyst system originally developed for alkyl halides. This work is placed in context by showing a direct comparison with a Ni catalyst for >40 examples spanning a range of primary, secondary, and tertiary substrates. This new C-C coupling is scalable and sustainable, and it exhibits a number of clear advantages in several cases over its Ni-based counterpart.
Direct C(sp2)-C(sp3) cross-coupling of diaryl zinc reagents with benzylic, primary, secondary, and tertiary alkyl halides
Dunsford, Jay J.,Clark, Ewan R.,Ingleson, Michael J.
supporting information, p. 5688 - 5692 (2015/05/19)
The direct C(sp2)-C(sp3) cross-coupling of diaryl zinc reagents with benzylic, primary, secondary, and tertiary alkyl halides proceeded in the absence of coordinating ethereal solvents at ambient temperature without the addition of a catalyst. The C(sp2)-C(sp3) cross-coupling showed excellent functional-group tolerance, and products were isolated in high yields, generally without the requirement for purification by chromatography. This process represents an expedient, operationally simple method for the construction of new C(sp2)-C(sp3) bonds. Zinc and you'll miss it. Direct C(sp2)-C(sp3) cross-coupling of diaryl zinc reagents with alkyl halides proceeded rapidly at ambient temperature without a coordinating ethereal solvent or an added catalyst (see scheme). This versatile, operationally simple approach to C(sp2)-C(sp3) bond formation enables the expedient construction of a diverse array of carbon-based structural motifs.
Iron-catalyzed cross-coupling of alkyl sulfonates with arylzinc reagents
Ito, Shingo,Fujiwara, Yu-Ichi,Nakamura, Eiichi,Nakamura, Masaharu
supporting information; experimental part, p. 4306 - 4309 (2009/12/26)
Iron-catalyzed cross-coupling reactions of primary and secondary alkyl sulfonates with arylzinc reagents proceed smoothly In the presence of excess TMEDA and a concomitant magnesium salt. The arylzinc reagents are prepared from the corresponding aryllithium or magnesium reagents with ZnI2. The In situ formation of alkyl Iodides and consecutive rapid cross-coupling avoids discrete preparation of the unstable secondary alkyl halides and also achieves high product selectivity.
Stille cross-couplings of unactivated secondary alkyl halides using monoorganotin reagents
Powell, David A.,Maki, Toshihide,Fu, Gregory C.
, p. 510 - 511 (2007/10/03)
The first catalyst that achieves Stille cross-couplings of secondary (as well as primary) alkyl halides has been developed. The method employs easily handled and inexpensive catalyst components (NiCl2 and 2,2′-bipyridine) and, through the use of monoorganotin reagents, avoids the formation of toxic and difficult-to-remove triorganotin side products. Copyright
The role of enthalpic and entropic factors in the isomerization equilibrium of aryladamantanes
Pimerzin,Sarkisova
, p. 94 - 102 (2007/10/03)
The chemical equilibrium of five positional isomerization reactions of aryladamantanes with different structures was studied in the liquid phase in the presence of AlCl3 in the range 303-423 K. Contributions to the equilibrium constants were analyzed using experimental and calculated data. The contributions were from symmetry, intermolecular interactions, differences in heat capacities of isomers, overall rotation of molecules, free or hindered rotation of groups in molecules, contribution of vibrations, differences in conformational composition, and intramolecular effects of interaction of substituents in molecules involved in the reaction. The significance of these contributions to the equilibrium constants of the transformations in question was shown. The enthalpies and changes in entropy for the reactions in the liquid and gaseous states were determined and discussed. A comparative analysis of the thermodynamic characteristics of positional isomerization of aryladamantanes, methyladamantanes, methyldiamantanes, and phenylcyclohexanes is given.
Generation and reactivity of 2-substituted adamantenes
Okazaki, Takao,Tokunaga, Kazuhiko,Kitagawa, Toshikazu,Takeuchi, Ken'ichi
, p. 549 - 561 (2007/10/03)
The title bridgehead olefins, generated by the dehalogenation of 1,2- dihalo-2-R-adamantanes (R = Me, Et, Ph, p-CF3C6H4) with excess t-BuLi, yielded 2-t-butyl-2-R-adamantanes (15), 1-t-butyl-2-R-adamantanes (16), and dimeric products. The ratios of the yields (%) of 16 to 15 were 20:3 (R = Me), 32: 3C6H4). 2- Alkyladamantenes predominantly yielded the products t-butylated at C(1), whereas 2-aryladamantenes gave the products t-butylated at C(2). The total yields of the dimers decreased with the bulkiness of substituents at position C(2). The dimerization of 2-methyladamantene gave a head-to-head dimer, 1- (2-methyl-1-adamantyl)-2-methyleneadamantane, as well as a head-to-tail dimer, 1-(2-methyl-2-adamantyl)-2-methyleneadamantane. The [4+2] cycloaddition between two molecules of 2-phenyladamantene, in which the phenyl group participates as a part of the diene, yielded a dimer of the head-to-tail type. These results suggest that: i) a substituent at position C(2) can kinetically stabilize 2-R-adamantene and suppress the dimerization, ii) 2-alkyladamantenes might have a biradical nature, and iii) the regioselective [4+2] cycloaddition and t-BuLi addition of 2-phenyladamantene in THF can be explained by assuming a certain contribution of zwitterionic nature in the double bond that may be dependent on the media and nucleophiles.
Adamantane-2-spiro-3'-diazirine in reactions with protic and aprotic acids
Isaev, S. D.,Zhalnina, G. G.,Murzinova, Z. N.,Lastovenko, S. I.,Yurchenko, A. G.
, p. 126 - 131 (2007/10/02)
During the action of strong protic acids on adamantane-2-spiro-3'-diazirine addition of the proton is accompanied by the elimination of a molecule of nitrogen and the formation of the intermediate 2-adamantyl cation.In the presence of nucleophiles the latter is converted into the corresponding 2-substituted derivatives of adamantane.Lewis acids promote isomerization of the cyclic diazirine to the linear diazo compound, and the main reaction product is adamantanone azine.Trifluoroacetic acid and bromine react by both mechanisms simultaneously. (In the latter case Br+ plays the role of the proton in the first stage.)
