- Tandem isomerization/hydroformylation/hydrogenation of internal alkenes to n-alcohols using Rh/Ru dual-or ternary-catalyst systems
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A one-pot three-step reaction, isomerization/hydroformylation/hydrogenation of internal alkenes to n-alcohols, was accomplished by employing a Rh/Ru dual-catalyst system. By using a combination of Rh(acac)(CO)2/ bisphosphite and Shvo's catalyst, (Z)-2-tridecene was converted to 1-tetradecanol in 83% yield with high normal/iso selectivity (n/i = 12). The method was applicable to other internal alkenes, including functionalized alkenes, such as an alkenol and an alkenoate. Furthermore, addition of a third component, Ru3(CO)12, effectively improved the n/i ratio in the tandem isomerization/hydroformylation/hydrogenation of methyl oleate (from n/i = 1.9 to 4.4). Control experiments revealed that the isomerization was mediated by both Rh and Ru and that the coexistence of Rh and Ru was essential for hydrogenation of aldehyde under H2/CO.
- Yuki, Yamato,Takahashi, Kohei,Tanaka, Yoshiyuki,Nozaki, Kyoko
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p. 17393 - 17400
(2014/01/06)
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- Synthesis of 1,9-nonanedioldiacetate and 1,7-heptanedioldiacetate mosquito repellants from aleuritic acid of lac resin
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1,9-Nonanedioldiacetate and 1,7-heptanedioldiacetate were synthesized from aleuritic acid (9,10,16-trihydroxyhexadecanoic acid), for the first time adopting simple procedure. Both the compounds showed mosquito repellant activity.
- Majee,Bhattacharya,Jaiswal,Bhattacharya,Prakash, Anil
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p. 109 - 110
(2013/05/23)
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- Electron transfer reduction of carboxylic acids using SmI 2-H2O-Et3N
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The first general method for efficient electron transfer reduction of carboxylic acids has been developed. The protocol using SmI2 - H 2O - Et3N allows for reduction of a variety of carboxylic acids in excellent yields and provides an attractive alternative to processes mediated by reactive alkali metals, lithium aluminum hydride, and boron hydrides. Of broader significance, the method allows acyl radical equivalents to be generated from carboxylic acids under mild reaction conditions.
- Szostak, Michal,Spain, Malcolm,Procter, David J.
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supporting information; experimental part
p. 840 - 843
(2012/04/11)
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- Bacterial CYP153A monooxygenases for the synthesis of omega-hydroxylated fatty acids
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CYP153A from Marinobacter aquaeolei has been identified as a fatty acid ω-hydroxylase with a broad substrate range. Two hotspots predicted to influence substrate specificity and selectivity were exchanged. Mutant G307A is 2- to 20-fold more active towards fatty acids than the wild-type. Residue L354 is determinant for the enzyme ω-regioselectivity.
- Honda Malca, Sumire,Scheps, Daniel,Kuehnel, Lisa,Venegas-Venegas, Elena,Seifert, Alexander,Nestl, Bettina M.,Hauer, Bernhard
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supporting information; experimental part
p. 5115 - 5117
(2012/06/30)
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- Thermoplastic polyester amides derived from oleic acid
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Three lipid-based Polyester Amides (PEAs) with varying ratios of ester and amide linkages were synthesized. Oleic acid was used as the starting material to produce the intermediates, characterized by MS and NMR, used for polymerization. PEAs were characterized by FTIR and GPC. The PEAs were constrained to have similar number average molecular weights, in the 2 × 104 range, thereby enabling comparison of their physical properties from a structural perspective. The thermal behavior of the polymers was assessed by DSC, DMA and TGA. Thermal degradation was not affected by ester/amide ratios, but Tg increased non-linearly with decreasing ester/amide ratios and correlated with hydrogen-bond density and repeating unit chain length. Crystallinity was studied by XRD and DSC. Degree of crystallization and multiple melting behavior as a function of cooling kinetics were explained well by hydrogen-bond density, repeating unit chain length and density of ester moieties. Mechanical properties were investigated by DMA and Tensile Analysis, with a non-linear increase of storage and tensile moduli recorded as a function of decreasing ester/amide ratios. The findings suggest how approaches to the synthesis of lipid-based PEAs can be targeted to the delivery of specific physical properties.
- Zuo, Jiaqing,Li, Shaojun,Bouzidi, Laziz,Narine, Suresh S.
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experimental part
p. 4503 - 4516
(2012/05/19)
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- Regioselective ω-hydroxylation of medium-chain n-alkanes and primary alcohols by CYP153 enzymes from Mycobacterium marinum and Polaromonas sp. strain JS666
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The oxofunctionalization of saturated hydrocarbons is an important goal in basic and applied chemistry. Biocatalysts like cytochrome P450 enzymes can introduce oxygen into a wide variety of molecules in a very selective manner, which can be used for the synthesis of fine and bulk chemicals. Cytochrome P450 enzymes from the CYP153A subfamily have been described as alkane hydroxylases with high terminal regioselectivity. Here we report the product yields resulting from C5-C12 alkane and alcohol oxidation catalyzed by CYP153A enzymes from Mycobacterium marinum (CYP153A16) and Polaromonas sp. (CYP153A P. sp.). For all reactions, byproduct formation is described in detail. Following cloning and expression in Escherichia coli, the activity of the purified monooxygenases was reconstituted with putidaredoxin (CamA) and putidaredoxin reductase (CamB). Although both enzyme systems yielded primary alcohols and α,ω-alkanediols, each one displayed a different oxidation pattern towards alkanes. For CYP153A P. sp. a predominant ω-hydroxylation activity was observed, while CYP153A16 possessed the ability to catalyze both ω-hydroxylation and α,ω- dihydroxylation reactions.
- Scheps, Daniel,Honda Malca, Sumire,Hoffmann, Helen,Nestl, Bettina M.,Hauer, Bernhard
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scheme or table
p. 6727 - 6733
(2011/11/30)
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- Functional thermoplastics from linear diols and diisocyanates produced entirely from renewable lipid sources
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An unsaturated terminal diol, 1,18-octadec-9-endiol (ODEDO), and a saturated terminal diol, 1,9-nonanediol (NDO), were synthesized from oleic acid. The feasibility of utilizing these new diols for the production of thermoplastic polyurethanes (TPUs) was demonstrated by reacting them with a fatty acid-derived diisocyanate, 1,7-heptamethylene diisocyanate (HPMDI), and a commercially available petroleum-derived diisocyanate, 1,6-hexamethylene diisocyanate (HDI). One type of phase structure was obtained for both TPUs in this study, owing to the similarity between the ODEDO and NDO molecular structure. In addition, double yielding behavior (observed for the first time in polyurethanes) was observed in the stress-strain curves for both TPU systems. Compared to the TPUs prepared from HDI, the totally biobased TPUs (ODEDO-NDO-HPDMI) demonstrated comparable properties within acceptable tolerances, considering the impacts on physical properties due to the odd-even effect introduced by the HPDMI. This work is the first that establishes the production of linear thermoplastic polyurethanes entirely from lipid feedstock.
- Hojabri, Leila,Kong, Xiaohua,Narine, Suresh S.
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experimental part
p. 911 - 918
(2011/01/03)
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- Iterative tandem catalysis of secondary diols and diesters to chiral polyesters
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The well-known dynamic kinetic resolution of secondary alcohols and esters was extended to secondary diols and diesters to afford chiral polyesters. This process is an example of iterative tandem catalysis (ITC), a polymerization method where the concurrent action of two fundamentally different catalysts is required to achieve chain growth. In order to procure chiral polyesters of high enantiomeric excess value (ee) and good molecular weight, the catalysts employed need to be complementary and compatible during the polymerization reaction. We here show that Shvo's catalyst and Novozym 435 fulfil these requirements. The optimal polymerization conditions of 1,1′-(1,3-phenylene) diethanol (1,3-diol) and diisopropyl adipate required 2mol% Shvo's catalyst and 12 mg Novozym 435 per mmol alcohol group in the presence of 0.5 M 2,4-dimethyl-3- pentanol as the hydrogen donor. With these conditions, chiral polyesters were obtained with peak molecular weights up to 15kDa, an ee value up to 99% and with 1-3% ketone end groups. Also with the structural isomer, 1,4-diol, a chiral polyester was obtained, albeit with lower molecular weight (8.3 kDa) and slightly lower ee (94%). Aliphatic secondary diols also resulted in enantio-enriched polymers but at most an ee of 46% was obtained with molecular weights in the range of 3.33.7 kDa. This low ee originates from the intrinsic low enantioselectivity of Novozym 435 for this type of secondary aliphatic diols. The results presented here show that ITC can be applied to procure chiral polyesters with good molecular weight and high ee from optically inactive AA-BB type monomers.
- Van As, Bart A.C.,Van Buijtenen, Jeroen,Mes, Tristan,Palmans, Anja R.A.,Meijer
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p. 8325 - 8332
(2008/09/16)
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- Deacylation of esters, thioesters and amides by a naphthalene-catalysed lithiation
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The reaction of different esters, thioesters and amides derived from pivalic, benzoic and 4-tert-butylbenzoic acids with an excess of lithium and a catalytic amount of naphthalene (8 mol%) led, after methanolysis, to the corresponding alcohols, thiols and amines, respectively, through a reductive non-hydrolytic procedure. This methodology represents a reasonable alternative to other non-reductive protocols. Georg Thieme Verlag Stuttgart.
- Behloul, Cherif,Guijarro, David,Yus, Miguel
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p. 309 - 314
(2007/10/03)
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- A new mild deprotecting method for O-benzylsulfonyl phenols and alcohols based on a DTBB-catalyzed lithiation
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A variety of alcohols and phenols, protected as the corresponding benzylsulfonic esters, were efficiently deprotected by selective reductive cleavage of the sulfur-oxygen bond, using an excess of lithium sand and a catalytic amount (5 mol%) of 4,4′-di-tert-butylbiphenyl (DTBB) as electron carrier, in THF at 0° C. This deprotection system was also efficient at -50 °C and was compatible with a wide range of other functional groups. Georg Thieme Verlag Stuttgart.
- Alonso, Francisco,Moglie, Yanina,Vitale, Cristian,Radivoy, Gabriel,Yus, Miguel
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p. 1971 - 1976
(2007/10/03)
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- Desilylation procedure via a naphthalene-catalysed lithiation reaction
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The reaction of silyl protected alcohols, amines and thiols with lithium powder and a catalytic amount of naphthalene, in THF, at 0°C led, after hydrolysis, to the recovery of the free alcohols, amines and thiols in very good yields. At least a phenyl group was required in the silyl protecting group for the success of the reaction. Some polyfunctionalised starting materials have successfully been deprotected. The stereochemical outcome of the deprotection of a silylated chiral secondary alcohol has also been studied and no racemization was observed. The process has shown to be a good alternative to the acid-catalysed desilylation procedures, the latter being not useful for the deprotection of some silylated tertiary alcohols.
- Behloul, Cherif,Guijarro, David,Yus, Miguel
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p. 6908 - 6915
(2007/10/03)
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- Deallyloxy- and debenzyloxycarbonylation of protected alcohols, amines and thiols via a naphthalene-catalysed lithiation reaction
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The naphthalene-catalysed lithiation of Alloc- and Cbz-protected alcohols, amines and thiols in THF at 0°C led, after quenching with methanol, to the recovery of the free alcohols, amines and thiols in short reaction times and with very good yields. The selectivity for the removal of the Alloc- or the Cbz- group in a polyfunctionalised substrate has been studied. The selective reductive cleavage of a benzylic carbon-oxygen bond was achieved in the presence of an allylic carbon-oxygen or carbon-nitrogen bond. This method represents a great improvement in comparison with the previously reported deprotection procedures by dissolving metals, since it avoids the use of the toxic liquid ammonia and, therefore, the need to perform the reaction at low temperatures.
- Behloul, Cherif,Guijarro, David,Yus, Miguel
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p. 9319 - 9324
(2007/10/03)
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- Detritylation Procedure under Non-Acidic Conditions: Naphthalene Catalysed Reductive Cleavage of Trityl Ethers
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The reaction of primary, secondary, allylic and benzylic trityl ethers 1 with lithium powder and a catalytic amount of naphthalene led to reductive cleavage of the trityl-oxygen bond, affording the corresponding alcohols 2 in good to excellent yields under very mild reaction conditions. The detritylation process could successfully be extended to several hydroxy, alkoxy and amino functionalised trityl ethers. This methodology represents a new and efficient detritylation procedure under non-acidic reaction conditions.
- Yus, Miguel,Behloul, Cherif,Guijarro, David
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p. 2179 - 2184
(2007/10/03)
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- DERMATOLOGICAL COMPOSITIONS AND METHODS
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Disclosed are methods and compositions for regulating the melanin content of mammalian melanocytes; regulating pigmentation in mammalian skin, hair, wool or fur; treating or preventing various skin and proliferative disorders; by administration of various compounds, including alcohols, diols and/or triols and their analogues.
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- A novel hydrogen transfer hydroalumination of alkenes with triisobutylaluminum catalyzed by Pd and other late transition metal complexes
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Hydrogen transfer hydroalumination of terminal alkenes and dienes can be achieved with 1.1 equiv. of (i-Bu)3Al and catalytic amounts of Cl2Pd(PPh3)2 and other late transition metal complexes containing Co, Rh, Ni, and Pt at ambient temperature in high yields.
- Gagneur, Sebastien,Makabe, Hidefumi,Negishi, Ei-Ichi
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p. 785 - 787
(2007/10/03)
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- Treatment of neurodegenerative diseases
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Disclosed are methods for increasing the differentiation of mammalian neuronal cells for purposes of treating neurodegenerative diseases or nerve damage by administration of various compounds including alcohols, diols and/or triols and their analogues.
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- CuCl2.2H2O MeOH. A new reagent system for the deprotection of tetrahydropyranyl ethers
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Cupric chloride dihydrate in methanol cleave the tetrahydropyranyl ethers to the corresponding alcohols in excellent yields under mild conditions.
- Davis, K. Joju,Bhalerao,Vittal Rao
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p. 2301 - 2308
(2007/10/03)
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- Zirconium borohydride - A versatile reducing agent for the reduction of electrophilic and nucleophilic substrates
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Zirconium borohydride, a potential reducing agent, reduces acids, esters, imines to the corresponding alcohols and secondary amines in good yield at room temperature within two hours. This facile reducing property was taken advantage off in the synthesis of pheromones and some novel chiral precursors for asymmetric synthesis.
- Narasimhan,Balakumar
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p. 4387 - 4395
(2007/10/03)
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- Reduction of carboxylic acids by tetraalkyl ammonium borohydride
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Tetraalkylammonium borohydride reduces carboxylic acids to the corresponding alcohols in good yields utilizing only stoichiometric quantities of hydride and also in the absence of any Lewis acids.
- Narasimhan,Swarnalakshmi,Balakumar
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p. 941 - 946
(2007/10/03)
-
- Treatment of diseases mediated by the nitric oxide/cGMP/protein kinase G pathway
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Disclosed are methods and compositions for stimulating cellular nitric oxide (NO) synthesis, cyclic guanosine monophosphate levels (cGMP), and protein kinase G (PKG) activity for purposes of treating diseases mediated by deficiencies in the NO/cGMP/PKG signal transduction pathway, by administration of various compounds including alcohols, diols and/or triols and their analogues.
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- Preparation of ω-hydroxy acids by reduction of α,ω-methylene diesters with NaBH4
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By reaction of the dicesium salts of long chain dicarboxylic acids (C atoms > 9) with methylene iodide the corresponding methylene diesters were prepared. These acylals, by reduction with NaBH4 in THF, give the corresponding ω-hydroxy acids.
- Benitez, Pilar,Delgado, Ana,Farrera, Joan-Anton,Ribo, Josep M.
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p. 1697 - 1702
(2007/10/03)
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- Lanthanoids in Organic Synthesis. I. The Novel Reduction of Carboxylic Acids with Samarium Diiodide-Base System
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Aromatic and aliphatic carboxylic acids were rapidly reduced with samarium diiodide by the addition of base in the presence of protic solvent at room temperature to the corresponding alcohols.Sodium benzoate was similarly reduced with samarium diiodide in the presence of H2O in a good yield.In the similar reactions of benzoic acid derivatives bearing carboxyl, formyl, carbamoyl, methoxyl, and chloro groups, these functional groups were also reduced to the corresponding alcohol or amine derivatives.Interestingly, the carboxyl and formyl groups of benzoic acids were partly reduced into the methyl group.
- Kamochi, Yasuko,Kudo, Tadahiro
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p. 3049 - 3054
(2007/10/02)
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- Olefin oxidative cleavage and dioxetane formation using triethylsilyl hydrotrioxide: Applications to preparation of potent antimalarial 1,2,4-trioxanes
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Oxidative cleavage of alkenyl esters and ethers using Et3SiOOOH was found to be easier than oxidative cleavage of hydrocarbon alkenes, and Et3SiOOOH was successfully applied to very short syntheses of new, simple, and potent antimalarial trioxanes 6 and 8.
- Posner,Oh,Milhous
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p. 4235 - 4238
(2007/10/02)
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- Lactones. 2. Enthalpies of hydrolysis, reduction, and formation of the C4-C13 monocyclic lactones. Strain energies and conformations
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The enthalpies of hydrolysis of the monocyclic lactones from γ-butyrolactone to tridecanolactone were determined calorimetrically, and the acyclic ethyl having the number of atoms were studied in the fashion. The enthalpies of reduction of the lactones to the corresponding α,ω-alkanediols with lithium triethylborohydride also were determined. The enthalpies of formation of the lactones and the ethyl esters were derived from these data. They were converted to values for the gas phase by measuring the enthalpies of vaporization of ethyl esters and of lactones. In the of γ-butyrolactone and δ-valerolactone, the enthalpies of formation were in good accord with the previously reported values determined via combustion calorimetry. The strain energies of the lactones were obtained via isodesmic reactions. Valerolactone had a strain energy of 11 kcal/mol, and the largest strain energy was found with octanolactone (13 kcal/mol). The conformations of γ-butyrolactone and δ-valerolactone were studied via MP2/6-31G* geometry optimizations, and the conformations of the other lactones were studied with use of the molecular mechanics program MM3. The energies of the lactones estimated via molecular mechanics were compared with the experimental results.
- Wiberg, Kenneth B.,Waldron, Roy F.
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p. 7697 - 7705
(2007/10/02)
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- A New Oxidizing Reagent: Triethylsilyl Hydrotrioxide
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Triethylsilyl hydrotrioxide (Et3SiOOOH) is a new, short-lived oxidizing agent that can react at -78 deg C directly and rapidly with olefins to form 1,2-dioxetanes and oxidatively cleaved carbonyl products.
- Posner, Gary H.,Webb, Kevin S.,Nelson, William M.,Kishimoto, Takashi,Seliger, Howard H.
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p. 3252 - 3254
(2007/10/02)
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- Hydroboration. 67. Cyclic Hydroboration of Acyclic α,ω-Dienes with 9-Borabicyclononane/Borane-Dimethyl Sulfide
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Hydroboration of acyclic α,ω-dienes, 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, and 1,13-tetradecadiene, with 2 molar equiv of 9-borabicyclononane (9-BBN), followed by redistribution of the resulting dumbbell-shaped trialkylboranes with 1 molar equiv of borane-methyl Sulfide complex (BMS), has been investigated.With 1,3-butadiene, the initial redistribution product, the five-membered boracyclane, borolane, underwent a rapid ring-opening reaction to give the known 1,6-diboracyclodecane. 1,4-Pentadiene and 1,5-hexadiene afforded the corresponding boracyclanes, borinane and borepane, in quantitative yields.With all other dienes, the initial redistribution products were polymeric.They were converted to the methyl esters by treatment with methanol, and these products were depolymerized into cyclic derivatives in 88-98percent yield by vacuum distillation at 175-200 deg C.In every case the cyclization was accompanied by varying amounts of isomerization so that the major products were both the parent B-methoxyboracyclane and the corresponding B-methoxy-2-n-alkylborinane.Thus, 1,6-heptadiene afforded B-methoxyborocane and B-methoxy-2-ethylborinane in 3:1 ratio and a total yield of 95percent.With 1,7-octadiene, 1,8-nonadiene, 1,9-decadiene and 1,11-dodecadiene, the isomerized product constituted the major constituent of the distillate. 1,13-Tetradecadiene afforded the parent boracyclane and the isomer in a 47:53 ratio and a combined yield of 82percent.The B-methoxyboracyclanes were converted to the corresponding cyclic ketones by the DCME reaction in 55-65percent yield.
- Brown, Herbert C.,Pai, Ganesh G.,Naik, Ramachandra G.
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p. 1072 - 1078
(2007/10/02)
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- Non-metal-requiring Catalyst Contained in Recovered Methyl Linolenate from an Autoxidizing Sample
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Non-metal-requiring catalysts in recovered methyl lenolenate from an autoxidizing sample were unstable on contact with silicic acid and the activity varied widely with the way of recovery, countercurrent extraction and column chromatography under different conditions.After reduction with stannous chloride, a substance was found which was characteristically present in the products deriver from the recovered methyl linolenate high in the catalytic activity.It was tentatively indentified by MS, IR, OsO4 oxidation-IO41- oxidation, and LiAlH4 reduction-IO41- oxidation as methyl 9,13-dihydroxy-10-epoxy-15-octadecenoate.
- Morita, Makio
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p. 2403 - 2408
(2007/10/02)
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