6975-98-0Relevant academic research and scientific papers
Preparation of Primary and Secondary Dialkylmagnesiums by a Radical I/Mg-Exchange Reaction Using sBu2Mg in Toluene
Knochel, Paul,Lutter, Ferdinand H.,Sunagatullina, Alisa S.
supporting information, (2022/02/16)
The treatment of primary or secondary alkyl iodides with sBu2Mg in toluene (25–40 °C, 2–4 h) provided dialkylmagnesiums that underwent various reactions with aldehydes, ketones, acid chlorides or allylic bromides. 3-Substituted secondary cyclohexyl iodides led to all-cis-3-cyclohexylmagnesium reagents under these exchange conditions in a highly stereoconvergent manner. Enantiomerically enriched 3-silyloxy-substituted secondary alkyl iodides gave after an exchange reaction with sBu2Mg stereodefined dialkylmagnesiums that after quenching with various electrophiles furnished various 1,3-stereodefined products including homo-aldol products (99 % dr and 98 % ee). Mechanistic studies confirmed a radical pathway for these new iodine/magnesium-exchange reactions.
A New Protocol for Catalytic Reduction of Alkyl Chlorides Using an Iridium/Bis(benzimidazol-2′-yl)pyridine Catalyst and Triethylsilane
Fukuyama, Takahide,Hamada, Yuki,Ryu, Ilhyong
, p. 3404 - 3408 (2021/07/14)
The reduction of alkyl chlorides using triethylsilane is investigated. Primary, secondary, tertiary, and benzylic C-Cl bonds are effectively converted into C-H bonds using an [IrCl(cod)] 2/2,6-bis(benzimidazol-2′-yl)pyridine catalyst system. This catalyst system is quite simple since the tridentate N-ligand can be easily prepared in one step from commercially available reagents.
UVA- and Visible-Light-Mediated Generation of Carbon Radicals from Organochlorides Using Nonmetal Photocatalyst
Matsubara, Ryosuke,Yabuta, Tatsushi,Md Idros, Ubaidah,Hayashi, Masahiko,Ema, Fumitoshi,Kobori, Yasuhiro,Sakata, Ken
, p. 9381 - 9390 (2018/07/25)
Carbon radicals are reactive species useful in various organic transformations. The C-X bond cleavage of organohalides by photoirradiation is a common method to generate carbon radicals in a controlled fashion. The use of organochloride substrates is still a formidable challenge due to the low reduction potential and the high dissociation energy of the C-Cl bond. In this report, we address these issues by using a nonmetal organic molecule with a relatively simple structure as a photocatalyst. In this catalyst (bis(dimethylamino)carbazole), the amino groups increase both the HOMO and LUMO energy levels, especially in the former. As a result, compared to the parent molecule, the new catalyst shows experimentally red-shifted absorption in the visible region and forms an excited state with better reducing capability. This photocatalyst was used in the reduction of unactivated aryl chlorides and alkyl chlorides in the presence of hydrogen atom donor at room temperature. The catalytic system can also be applied to the coupling of aryl chlorides with electron-rich arene and heteroarenes to affect the C-C bond-forming reactions. Our mechanistic study results support the assumption that carbon radicals are formed from the organochlorides via a single-electron-transfer step.
One-step Pd/C and Eu(OTf)3 catalyzed hydrodeoxygenation of branched C11 and C12 biomass-based furans to the corresponding alkanes
Keskiv?li, Juha,Wrigstedt, Pauli,Lagerblom, Kalle,Repo, Timo
, p. 40 - 45 (2017/02/05)
Solvent-free NaOH catalyzed aldol condensation of biomass-derived 5-hydroxymethyl furfural (HMF) and furfural with methyl isobutyl ketone (MIBK) was studied, producing branched C11and C12furan compounds in high yields of up to 96%. Through use of a Pd/C and Eu(OTf)3catalytic system, the condensation products of the bio-based starting materials were further hydrodeoxygenated (HDO) in one-step to biofuel compatible branched alkanes 2-methylundecane (3) and 2-methyldecane (4) in excellent yields of 90% and 98%, respectively. In the one-step HDO developed herein, the variation of solvent had a significant effect on the reaction route and degree of conversion of furans to alkanes in the HDO process. Very high overall yields of alkanes 3 (86%) and 4 (94%) were obtained starting from the biomass-based HMF and furfural.
Photoinduced Charge-Transfer State of 4-Carbazolyl-3-(trifluoromethyl)benzoic Acid: Photophysical Property and Application to Reduction of Carbon?Halogen Bonds as a Sensitizer
Matsubara, Ryosuke,Shimada, Toshiyuki,Kobori, Yasuhiro,Yabuta, Tatsushi,Osakai, Toshiyuki,Hayashi, Masahiko
supporting information, p. 2006 - 2010 (2016/07/28)
The photoinduced persistent intramolecular charge-transfer state of 4-carbazolyl-3-(trifluoromethyl)benzoic acid was confirmed. It showed a higher catalytic activity in terms of yield and selectivity in the photochemical reduction of alkyl halides compared to the parent carbazole. Even unactivated primary alkyl bromides could be reduced by this photocatalyst. The high catalytic activity is rationalized by considering the slower backward single-electron transfer owing to the spatial separation of the donor and acceptor subunits.
Fischer–Tropsch synthesis with cobalt catalyst and zeolite multibed arrangement
Asalieva, E. Yu.,Kul’chakovskaya,Sineva,Mordkovich,Bulychev
, p. 275 - 280 (2016/06/09)
The role of zeolite in transformations of hydrocarbons produced from CO and H2 over a Fischer–Tropsch cobalt catalyst under the conditions of multibed arrangement of the cobalt catalyst and the zeolite has been determined. Hydrocarbon conversion over the HBeta zeolite occurs via the bimolecular mechanism, as evidenced by a low methane yield and a high yield of unsaturated gaseous and liquid hydrocarbons. The conversion over the CaA zeolite obeys the unimolecular mechanism, as evidenced by the formation of increased amounts of methane and saturated gaseous C2–C4 hydrocarbons.
Simple, chemoselective, catalytic olefin isomerization
Crossley, Steven W. M.,Barabé, Francis,Shenvi, Ryan A.
supporting information, p. 16788 - 16791 (2015/01/09)
Catalytic amounts of Co(SaltBu,tBu)Cl and organosilane irreversibly isomerize terminal alkenes by one position. The same catalysts effect cycloisomerization of dienes and retrocycloisomerization of strained rings. Strong Lewis bases like amines and imidazoles, and labile functionalities like epoxides, are tolerated.
Solvent-free synthesis of C10 and C11 branched alkanes from furfural and methyl isobutyl ketone
Yang, Jinfan,Li, Ning,Li, Guangyi,Wang, Wentao,Wang, Aiqin,Wang, Xiaodong,Cong, Yu,Zhang, Tao
, p. 1149 - 1152 (2013/07/26)
Our best results jet: C10 and C11 branched alkanes, with low freezing points, are synthesized through the aldol condensation of furfural and methyl isobutyl ketone from lignocellulose, which is then followed by hydrodeoxygenation. These jet-fuel-range alkanes are obtained in high overall yields (≈90 %) under solvent-free conditions. Copyright
A structure-activity study of Ni-catalyzed alkyl-alkyl kumada coupling. Improved catalysts for coupling of secondary alkyl halides
Ren, Peng,Vechorkin, Oleg,Von Allmen, Kim,Scopelliti, Rosario,Hu, Xile
supporting information; experimental part, p. 7084 - 7095 (2011/06/26)
A structureactivity study was carried out for Ni catalyzed alkylalkyl Kumada-type cross coupling reactions. A series of new nickel(II) complexes including those with tridentate pincer bis(amino)amide ligands (RN2N) and those with bidentate mixed amino-amide ligands (RNN) were synthesized and structurally characterized. The coordination geometries of these complexes range from square planar, tetrahedral, to square pyramidal. The complexes had been examined as precatalysts for cross coupling of nonactivated alkyl halides, particularly secondary alkyl iodides, with alkyl Grignard reagents. Comparison was made to the results obtained with the previously reported Ni pincer complex [( MeN2N)NiCl]. A transmetalation site in the precatalysts is necessary for the catalysis. The coordination geometries and spin-states of the precatalysts have a small or no influence. The work led to the discovery of several well-defined Ni catalysts that are significantly more active and efficient than the pincer complex [(MeN2N)NiCl] for the coupling of secondary alkyl halides. The best two catalysts are [(HNN)Ni(PPh3)Cl] and [(HNN)Ni(2,4-lutidine)Cl]. The improved activity and efficiency was attributed to the fact that phosphine and lutidine ligands in these complexes can dissociate from the Ni center during catalysis. The activation of alkyl halides was shown to proceed via a radical mechanism.
A catalytic application of Co/Zr heterobimetallic complexes: Kumada coupling of unactivated alkyl halides with alkyl grignard reagents
Zhou, Wen,Napoline, Jonathan Wesley,Thomas, Christine M.
scheme or table, p. 2029 - 2033 (2011/06/25)
Tris(phosphanylamide) early/late heterobimetallic Zr/Co complexes, ClZr(R′NPR2)3CoI [R′ = iPr, R = Ph (1), R′ = 2,4,6-trimethylphenyl, R = iPr (2), R′ = R = iPr (3)], have been utilized as catalysts for the cross-coupling of alkyl halides with n-octylmagnesium bromide. While yields are consistently higher for alkyl bromide substrates, it is found that these unusual heterobimetallic complexes are also active towards more challenging alkyl chloride substrates. This is particularly interesting in light of the fact that monometallic cobalt complexes are inert towards these substrates, suggesting that Zr also plays a role in catalysis. Radical trapping studies suggest that a one-electron transfer radical oxidative addition pathway is operative.
