- Method for synthesizing 6-chloro-1-hexanol by taking 1,6-hexanediol and cyanuric chloride as raw materials
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The invention relates to the field of organic synthesis, and discloses a method for synthesizing 6-chloro-1-hexanol by using 1,6-hexanediol and cyanuric chloride as raw materials, wherein the method comprises the following steps: 1) dissolving cyanuric chloride in a solvent A, stirring to react, and obtaining a solution for later use after the reaction is finished; 2) preparing 1,6-hexanediol or asolution thereof; 3) slowly dropwise adding the solution obtained in the step (1) into the 1,6-hexanediol or the solution thereof obtained in the step (2), carrying out heat preservation reaction after dropwise adding is finished, filtering reaction liquid after the reaction is finished, rinsing a filter cake by using a solvent B, and collecting filtrate; 4) rectifying the filtrate obtained in the step 3 to prepare the finished product. According to the method, 1,6-hexanediol and cyanuric chloride are used as raw materials to synthesize 6-chloro-1-hexanol, the raw materials are cheap and easyto obtain, the purity of the obtained product can reach 99% or above, the yield can reach 95% or above, the reaction condition is mild, aftertreatment is simple, and the method is more suitable for large-scale industrial application.
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Paragraph 0035-0062
(2021/01/29)
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- Chemoselective Cleavage of Si-C(sp3) Bonds in Unactivated Tetraalkylsilanes Using Iodine Tris(trifluoroacetate)
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Organosilanes are synthetically useful reagents and precursors in organic chemistry. However, the typical inertness of unactivated Si-C(sp3) bonds under conventional reaction conditions has hampered the application of simple tetraalkylsilanes in organic synthesis. Herein we report the chemoselective cleavage of Si-C(sp3) bonds of unactivated tetraalkylsilanes using iodine tris(trifluoroacetate). The reaction proceeds smoothly under mild conditions (-50 °C to room temperature) and tolerates various polar functional groups, thus enabling subsequent Tamao-Fleming oxidation to provide the corresponding alcohols. NMR experiments and density functional theory calculations on the reaction indicate that the transfer of alkyl groups from Si to the I(III) center and the formation of the Si-O bond proceed concertedly to afford an alkyl-λ3-iodane and silyl trifluoroacetate. The developed method enables the use of unactivated tetraalkylsilanes as highly stable synthetic precursors.
- Matsuoka, Keitaro,Komami, Narumi,Kojima, Masahiro,Mita, Tsuyoshi,Suzuki, Kimichi,Maeda, Satoshi,Yoshino, Tatsuhiko,Matsunaga, Shigeki
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p. 103 - 108
(2021/01/13)
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- A highly active and air-stable ruthenium complex for the ambient temperature anti-markovnikov reductive hydration of terminal alkynes
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The conversion of terminal alkynes to functionalized products by the direct addition of heteroatom-based nucleophiles is an important aim in catalysis. We report the design, synthesis, and mechanistic studies of the half-sandwich ruthenium complex 12, which is a highly active catalyst for the anti-Markovnikov reductive hydration of alkynes. The key design element of 12 involves a tridentate nitrogen-based ligand that contains a hemilabile 3-(dimethylamino) propyl substituent. Under neutral conditions, the dimethylamino substituent coordinates to the ruthenium center to generate an air-stable, 18-electron, κ3-complex. Mechanistic studies show that the dimethylamino substituent is partially dissociated from the ruthenium center (by protonation) in the reaction media, thereby generating a vacant coordination site for catalysis. These studies also show that this substituent increases hydrogenation activity by promoting activation of the reductant. At least three catalytic cycles, involving the decarboxylation of formic acid, hydration of the alkyne, and hydrogenation of the intermediate aldehyde, operate concurrently in reactions mediated by 12. A wide array of terminal alkynes are efficiently processed to linear alcohols using as little as 2 mol % of 12 at ambient temperature, and the complex 12 is stable for at least two weeks under air. The studies outlined herein establish 12 as the most active and practical catalyst for anti-Markovnikov reductive hydration discovered to date, define the structural parameters of 12 underlying its activity and stability, and delineate design strategies for synthesis of other multifunctional catalysts.
- Zeng, Mingshuo,Li, Le,Herzon, Seth B.
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supporting information
p. 7058 - 7067
(2014/06/09)
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- Temporal separation of catalytic activities allows anti-Markovnikov reductive functionalization of terminal alkynes
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There is currently great interest in the development of multistep catalytic processes in which one or several catalysts act sequentially to rapidly build complex molecular structures. Many enzymes - often the inspiration for new synthetic transformations - are capable of processing a single substrate through a chain of discrete, mechanistically distinct catalytic steps. Here, we describe an approach to emulate the efficiency of these natural reaction cascades within a synthetic catalyst by the temporal separation of catalytic activities. In this approach, a single catalyst exhibits multiple catalytic activities sequentially, allowing for the efficient processing of a substrate through a cascade pathway. Application of this design strategy has led to the development of a method to effect the anti-Markovnikov (linear-selective) reductive functionalization of terminal alkynes. The strategy of temporal separation may facilitate the development of other efficient synthetic reaction cascades.
- Li, Le,Herzon, Seth B.
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- Regioselective reductive hydration of alkynes to form branched or linear alcohols
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The regioselective reductive hydration of terminal alkynes using two complementary dual catalytic systems is described. Branched or linear alcohols are obtained in 75-96% yield with ?25:1 regioselectivity from the same starting materials. The method is compatible with terminal, di-, and trisubstituted alkenes. This reductive hydration constitutes a strategic surrogate to alkene oxyfunctionalization and may be of utility in multistep settings.
- Li, Le,Herzon, Seth B.
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supporting information
p. 17376 - 17379,4
(2020/09/16)
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- Oxidation of monohydric and dihydric alcohols with CCl4 catalyzed by molybdenum compounds
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Mo(CO)6 catalyzed oxidation of alcohols and diols with tetrachloromethane. Primary oxidation products in reaction of alcohols with CCl4 are alkyl hypochlorites, and final products depending on the structure of initial alcohol are aldehydes (as acetals), ketones, chloroketones, and esters.
- Khusnutdinov,Shchadneva,Burangulova,Muslimov,Dzhemilev
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p. 1615 - 1621
(2007/10/03)
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- Efficient method for the deprotection of tert-butyldimethylsilyl ethers with TiCl4-Lewis base complexes: Application to the synthesis of 1β-methylcarbapenems
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TiCl4-Lewis base (AcOEt, CH3NO2) complexes smoothly deprotected tert-butyldimethylsilyl (TBDMS) ethers. The reaction velocity with these complexes, which seemed less reactive due to the influence of Lewis bases, was considerably greater than that with TiCl4 alone. Selective desilylations between aliphatic and aromatic TBDMS ethers (1 and 5), between 1 and benzyl, allyl, tosyl, methoxyphenyl, and chloroacetyl ethers (13, 14, 15, 16, and 17), and between TBDMS and TBDPS ethers (18 and 19) were successfully performed. Desilylation of TBDMS-aldol, acyloin, and β-lactam analogues 9-12 proceeded smoothly due to anchimeric assistance by the neighboring carbonyl groups. The present method was successfully applied to the practical synthesis of 1β-methylcarbapenems 20a′-f′.
- Iida, Akira,Okazaki, Hiroki,Misaki, Tomonori,Sunagawa, Makoto,Sasaki, Akira,Tanabe, Yoo
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p. 5380 - 5383
(2007/10/03)
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- Process for the preparation of α-bromo, ω-chloroalkanes
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Described is a process for easily preparing an α-bromo,ω-chloroalkane which is high in purity represented by the formula: Br(CH2)n Cl in which n stands for an integer of 4 to 12. The process comprises reacting in an organic solvent an α,ω-dichloroalkane with an αω-dibromoalkane. As the organic solvent, an aprotic nitrogen-containing or sulfur-containing organic solvent having a dielectric constant at 20° C. of 20 or larger, for example, N,N-dimethylformamide, N,N-dimethylacetamide or N,N-dimethylimidazolidinone is preferred.
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- Chemoselective oxidation of organozine reagents with oxygen
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Functionalized organozinc compounds prepared by hydrozincation, carbozincation or by boron-zinc exchange can be directly oxidized in a selective manner to the corresponding functionalized alcohols or hydroperoxides depending on the reaction conditions.
- Klement, Ingo,Luetjens, Henning,Knochel, Paul
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p. 9135 - 9144
(2007/10/03)
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- Oxidation of zinc organometallics prepared by hydrozincation or carbozincation using oxygen
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Organozinc compounds prepared by the hydrozincation or carbazincation of functionalized unsaturated molecules can be directly oxidized by oxygen affording alcohols after reductive workup in satisfactory yields.
- Klement, Ingo,Luetjens, Henning,Knochel, Paul
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p. 3161 - 3164
(2007/10/02)
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- 14B(R) isomers of novel tetracyclic compounds having anti-allergic and anti-asthmatic activities, and their use
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An optically active compound of formula (I): STR1 in which R3 represents groups of formula --A--COOR4, wherein A represents alkylene groups having 3 or 5 carbon atoms and R4 represents hydrogen or an alkyl group having 1 to 4 carbon atoms; or a pharmaceutically acceptable salt thereof.
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- Tetracyclic compounds having anti-allergic and anti-asthmatic activities and their use
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Compounds of formula (I): STR1 in which: Q is nitrogen or =CH--; R1 and R2 are hydrogen, alkyl, alkoxy, hydroxy, trifluoromethyl or halogen; and R3 is a substituted alkyl groups or a pharmaceutically acceptable salt thereof have valuable anti-allergic and anti-asthmatic activities. The compounds are prepared by reacting a corresponding compound where R3 is replaced by a hydrogen atom with a compound to introduce the group R3.
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- Preparation of haloalcohols
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Haloalcohols of the general formula I where X is straight-chain or branched, substituted or unsubstituted alkylene of 4 or more carbon atoms in the chain, which may be interrupted by one or more heteroatoms, and Hal is halogen, are prepared by reacting a diol of the general formula II where X has the above meanings, with an aqueous hydrogen halide solution in a water-immiscible organic solvent which is inert under the reaction conditions, at from 50° to 150° C., using an excess of hydrogen halide, based on the diol of the general formula II, of from 10 to 200 mole percent and setting a volume ratio of inorganic phase: organic phase of from 1:2 to 1:50.
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- Novel Reduction of Carboxylic Acids and Hydroboration of Olefins by Electrolysis of Sodium Borohydride
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Electrochemical oxidation of sodium borohydride in diglyme containing aliphatic or aromatic carboxylic acids followed by acid-catalyzed hydrolysis afforded the corresponding primary alcohols in good yields.Furthermore, similar electrochemical oxidation in the presence of a variety of olefins instead of carboxylic acids, followed by treatment with alkaline-hydrogen peroxide, brought about novel electrochemical hydroboration to give the corresponding alcohols regio- and stereoselectively in good yields.
- Shundo, Ryushi,Matsubara, Yoshiharu,Nishiguchi, Ikuzo,Hirashima, Tsuneaki
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p. 530 - 534
(2007/10/02)
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- Metal-assisted Reactions. Part 17. Ring-opening and Dimerization of Cyclic Ethers by Titanium Halides
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Reaction of TiCl4 or TiBr4 with a variety of cyclic ethers gives, predominantly, products resulting from simple ring-opening or from ring-opening with simultaneous condensation to dimeric species.The variations in yields of these two kinds of products might be correlated qualitatively with an initial formation of the complex TiX4*2E (X = Cl or Br; E = cyclic ether) in which the ethers were held in a cis or trans relationship.Although such a correlation might suggest that TiCl4 but not TiBr4 exerts a template effect on the condensation, stereochemical considerations of the reaction products indicate otherwise.TiCl3 and VCl3 do not give similar results and TiF4 gives no reaction.
- Delaney, Paul A.,Johnstone, Robert A. W.,Entwistle, Ian D.
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p. 1855 - 1860
(2007/10/02)
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- Selective Reductions: 33. Potassium Triisopropoxyborohydride as a Selective Reducing Agent in Organic Synthesis. Reaction with Selected Organic Compounds Containing Representative Functional Groups
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The approximate rate and stoichiometry of the reaction of excess pure potassium triisopropoxyborohydride, KIPBH, with 56 selected compounds containing representative functional groups under standardized conditions (tetrahydrofuran, 0 deg C) was examined in order to define the characteristics of the reagent for selective reductions.Primary, secondary, and tertiary alcohols evolve hydrogen partially, even after a long period of time.Phenol also generates partial hydrogen, and the reactions of those amines and thiols studied with the reagent are very slow.Aldehydes andketones are reduced rapidly and quantitatively to give the corresponding alcohols.Unlike sodium and potassium borohydrides, KIPBH is very stereoselective. 2-Methylcyclohexanone can be reduced to the correspondingly less stable isomer, cis-2-methylcyclohexanol, in a high ratio (91percent cis isomer).Cinnamaldehyde is rapidly reduced to cinnamylalcohol, and further reduction is very slow under these conditions.Anthraquinone is cleanly reduced to 9,10-dihydro-9,10-anthracenediol.Carboxylic acids liberate hydrogen only partially, and further reduction is very slow.Acid chlorides consume 1 equiv of hydride rapidly, but the corresponding aldehydes do not form.Esters are almost inert toward the reagent. γ-Butyrolactone and phthalide are reduced only slowly.Epoxides are inert toward the reagent.Primary aliphatic amides evolve hydrogen slowly and primary aromatic amides evolve 1 equiv of hydrogen, but no significant reduction occurs.Tertiary amides and nitriles are inert toward the reagent.Of the nitrogen compounds studied, nitrobenzene is partially reduced after 48h, while azobenzene and azoxybenzene are inert.Partial reduction ofcyclohexanone oxime is observed, while phenyl isocyanate, pyridine, and pyridine N-oxide are inert under these conditions.Di n-butyl disulfide and diphenyl disulfide are reduced rapidly and quantitatively to the corresponding mercaptans with partial hydrogen evolution.Other sulfur compounds studied, such as p-tolyl methyl sulfide, diphenylsulfone, methanesulfonic acid, and p-toluenesulfonic acid, are inert toward the reagent.Only partial reduction of cyclohexyl tosylate is observed.Potassium triisopropoxyborohydride is a valuable reagent in boron chemistry.Thus, it transfers 1 equiv of hydride to dialkylhaloboranes, and the resulting dialkylborane can be transformed to a mixed trialkylborane, providing a potential route to mixed trialkylcarbinols or unsymmetrical ketones.The reagent rapidly transfers hydride to even severely hindered trialkylboranes, providing a simple synthetic route to these useful reagents.Finally, it readily converts 2-bromo-trans-vinylboronic esters to the cis-vinylboronic esters, providing a convenient synthetic route to these derivatives.
- Brown, Herbert C.,Cha, Jin Soon,Nazer, Behrooz,Kim, Suk-Choong,Krishnamurthy, Sundaram
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p. 885 - 892
(2007/10/02)
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- ETUDE DES INTERACTIONS ENTRE FONCTIONS ALCOOL ET AMINE: EVOLUTION THERMIQUE D'HYDROXYDES ET DE SELS D'ω-TRIALKYLAMMONIO ALCANOLS-1
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The thermolysis of ω-hydroxyalkyltrialkylammonium hydroxides (Φ=4-8) was investigated: Elimination to alkenol competes with substitution to amino alcohol; the hydroxy group can be alkylated into aliphatic ethers by an intermolecular process; the intramolecular cyclization into cyclic ethers is important only when ω=4.Substitution reaction in amino alcohols is the main pathway for the thermolysis of ω-hydroxyalkyltrimethylammonium acetates (ω=5,6) and chloride (ω=6).
- Barbry, Didier,Hasiak, Bruno
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p. 1734 - 1744
(2007/10/02)
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- SYNTHESIS OF HIGHER ACETYLENIC ALCOHOLS
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The alkylation of 1-alkynes in various solvents was investigated, and the optimum conditions for the production of acetylenic alcohols were obtained.
- Kovalev, B. G.,Matveeva, E. D.,Stan, V. V.,Vovk, G. A.,Yudin, L. G.,Kost, A. N.
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p. 1728 - 1733
(2007/10/02)
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