- Tailoring Polyethers for Post-polymerization Functionalization by Cross Metathesis
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Olefin cross metathesis is reported for the first time to attach small molecules to a range of novel polyethers with a poly(ethylene glycol) backbone and pendent alkene groups, allowing for a loading of up to one compound per monomer unit. These polymers are tailored to prevent the occurrence of self metathesis (reaction of the polymer with itself) by varying the substitution on the pendent alkenes, thus steering their reactivity toward olefin cross metathesis. Efficient functionalization has been observed for a range of coupling partners as a proof of concept for the use of olefin metathesis to graft small and larger molecules to polyethers for drug delivery. This approach also paves the way for the use of olefin cross metathesis as an efficient method to functionalize a wide variety of polymers with pendent olefin groups.
- Morrison, Stephen D.,Liskamp, Rob M. J.,Prunet, Jo?lle
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- Thermal Unequilibrium of PdSn Intermetallic Nanocatalysts: From In Situ Tailored Synthesis to Unexpected Hydrogenation Selectivity
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Effective control on chemoselectivity in the catalytic hydrogenation of C=O over C=C bonds is uncommon with Pd-based catalysts because of the favored adsorption of C=C bonds on Pd surface. Here we report a unique orthorhombic PdSn intermetallic phase with unprecedented chemoselectivity toward C=O hydrogenation. We observed the formation and metastability of this PdSn phase in situ. During a natural cooling process, the PdSn nanoparticles readily revert to the favored Pd3Sn2 phase. Instead, using a thermal quenching method, we prepared a pure-phase PdSn nanocatalyst. PdSn shows an >96 % selectivity toward hydrogenating C=O bonds of various α,β-unsaturated aldehydes, highest in reported Pd-based catalysts. Further study suggests that efficient quenching prevents the reversion from PdSn- to Pd3Sn2-structured surface, the key to the desired catalytic performance. Density functional theory calculations and analysis of reaction kinetics provide an explanation for the observed high selectivity.
- Chen, Minda,Dolge, Kevin,Gebre, Mebatsion,Heintz, Patrick,Huang, Wenyu,Jing, Dapeng,Lamkins, Andrew,Liu, Fudong,Ordonez, Claudio,Qi, Long,Shoemaker, Daniel P.,Wang, Bin,Yan, Yu,Zhang, Biying
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Read Online
- Regioselective Reduction of α,β-Unsaturated Carbonyl Compounds to Allylic Alcohols by Vapor Phase Hydrogen Transfer Reaction over MgO-B2O3 Catalyst
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Regioselective reduction of α,β-unsatureted carbonyl compounds to the corresponding allylic alcohols was performed effectively by vapor phase hydrogen-transfer reaction over MgO-B2O3 (Mg/B = 100/2) catalyst using secondary alcohols as hydrogen donor.
- Ueshima, Michio,Shimasaki, Yuuji
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- Regiospecific Synthesis of Calcium-Independent Daptomycin Antibiotics using a Chemoenzymatic Method
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Daptomycin (DAP) is a calcium (Ca2+)-dependent FDA-approved antibiotic drug for the treatment of Gram-positive infections. It possesses a complex pharmacophore hampering derivatization and/or synthesis of analogues. To mimic the Ca2+-binding effect, we used a chemoenzymatic approach to modify the tryptophan (Trp) residue of DAP and synthesize kinetically characterized and structurally elucidated regiospecific Trp-modified DAP analogues. We demonstrated that the modified DAPs are several times more active than the parent molecule against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria. Strikingly, and in contrast to the parent molecule, the DAP derivatives do not rely on calcium or any additional elements for activity.
- Mupparapu, Nagaraju,Lin, Yu-Hsin Cindy,Kim, Tae Ho,Elshahawi, Sherif I.
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supporting information
p. 4176 - 4182
(2021/02/01)
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- PROCESS FOR PREPARING 2-METHALLYL ALCOHOL
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Step 1: reacting a basic aqueous solution 2 - with 1 methallyl chloride in the presence of a catalyst. 1-th step of separating the oil layer and the water layer by adding an NH 2 aqueous solution to the reacted product in Step 2. The method 2 - wherein 3 metaallyl alcohol is obtained from the down stream by separating the oil layer into a down stream and an upstream using a boiling point difference. And. The catalyst is an ionic liquid (Ionic liquid) and relates to a method for producing 2 -methallyl alcohol. To the present invention, 2 - metaallyl alcohol having high selectivity and high yield can be provided.
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Paragraph 0049-0066
(2021/06/09)
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- METHOD FOR PREPARING 2-METHALLYL ALCOHOL
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2 - Allyl chloride is reacted in the presence of a catalyst in a basic aqueous solution. The catalyst is an ionic liquid (Ionic liquid) and relates to a method for producing 2 -methallyl alcohol. To the present invention, 2 - metaallyl alcohol having high selectivity and high yield can be provided.
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Paragraph 0036-0053
(2021/06/09)
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- METHOD FOR PREPARING 2-METHALLYL ALCOHOL
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The present invention is in the presence of a nonionic surfactant. 2 - A process for the preparation of 2 -methallyl alcohol comprising reacting diallyl chloride with a basic aqueous solution. To the present invention, 2 -methallyl alcohol having a high yield can be produced without using a catalyst while the reaction is simple and raw material costs are low.
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Paragraph 0033-0062
(2021/06/09)
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- METHOD FOR SEPARATING AND PREPARING 2-METHALLYL ALCOHOL
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The reaction of 2 -methallyl chloride with a basic aqueous solution to produce a 1-phase reaction solution (Step 1). 1: The reaction solution 2 is prepared by adding an aqueous alkali metal salt solution or an alkaline earth metal salt aqueous solution to the reaction solution to produce an agent 2. The method 2 according to claim 3, wherein the reaction mixture is separated into a water layer and an oil layer. The 2 -methallyl alcohol according to claim 4, wherein 2 -allyl alcohol is separated from the oil layer. To the present invention, 2 - metaallyl alcohol can be separated and recovered at a high recovery rate.
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Paragraph 0038-0053
(2021/06/09)
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- SYSTEMS AND METHODS FOR REGIOSELECTIVE CARBONYLATION OF 2,2-DISUBSTITUTED EPOXIDES FOR THE PRODUCTION OF ALPHA,ALPHA-DISUBSTITUTED BETA-LACTONES
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Provided are methods of producing carbonyl compounds (e.g., carbonyl containing compounds) and catalysts for producing carbonyl compounds. Also provided are methods of making polymers from carbonyl compounds and polymers formed from carbonyl compounds. A method may produce carbonyl compounds, such as, for example α,α-disubstituted carbonyl compounds (e.g., α,α-disubstituted β-lactones). The polymers may be produced from α,α-disubstituted β-lactones, which may be produced by a method described herein.
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Paragraph 0082
(2021/01/29)
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- Copper-Catalyzed Enantiotopic-Group-Selective Allylation of gem-Diborylalkanes
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We report a copper-catalyzed enatiotopic-group-selective allylation of gem-diborylalkanes with allyl bromides. The combination of copper(I) bromide and H8-BINOL derived phosphoramidite ligand proved to be the most effective catalytic system to provide various enantioenriched homoallylic boronate esters, containing a boron-substituted stereogenic center that is solely derived from gem-diborylalkanes, in good yields with high enantiomeric ratios under mild conditions. Experimental and theoretical studies have been conducted to elucidate the reaction mechanism, revealing how the enatiotopic-group-selective transmetalation of gem-diborylalkanes with chiral copper complex occurs to generate chiral α-borylalkyl-copper species for the first time. Additional synthetic applications to the synthesis of various chiral building blocks are also included.
- Kim, Minjae,Park, Bohyun,Shin, Minkyeong,Kim, Suyeon,Kim, Junghoon,Baik, Mu-Hyun,Cho, Seung Hwan
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supporting information
p. 1069 - 1077
(2021/01/25)
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- Synergistic Relay Reactions To Achieve Redox-Neutral α-Alkylations of Olefinic Alcohols with Ruthenium(II) Catalysis
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Herein, we report a ruthenium-catalyzed redox-neutral α-alkylation of unsaturated alcohols based on a synergistic relay process involving olefin isomerization (chain walking) and umpolung hydrazone addition, which takes advantage of the interaction between the two rather inefficient individual reaction steps to enable an efficient overall process. This transformation shows the compatibility of hydrazone-type “carbanions” and active protons in a one-pot reaction, and at the same time achieves the first Grignard-type nucleophilic addition using olefinic alcohols as latent carbonyl groups, providing a higher yield of the corresponding secondary alcohol than the classical hydrazone addition to aldehydes does. A broad scope of unsaturated alcohols and hydrazones, including some complex structures, can be successfully employed in this reaction, which shows the versatility of this approach and its suitability as an alternative, efficient means for the generation of secondary and tertiary alcohols.
- Kan, Jian,Li, Chao-Jun,Li, Chen-Chen,Li, Jianbin,Lv, Leiyang,Qiu, Zihang
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supporting information
p. 4544 - 4549
(2020/02/04)
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- Nickel-Catalyzed Asymmetric Reductive 1,2-Carboamination of Unactivated Alkenes
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Starting from diverse alkene-tethered aryl iodides and O-benzoyl-hydroxylamines, the enantioselective reductive cross-electrophilic 1,2-carboamination of unactivated alkenes was achieved using a chiral pyrox/nickel complex as the catalyst. This mild, modular, and practical protocol provides rapid access to a variety of β-chiral amines with an enantioenriched aryl-substituted quaternary carbon center in good yields and with excellent enantioselectivities. This process reveals a complementary regioselectivity when compared to Pd and Cu catalysis.
- He, Jun,Xue, Yuhang,Han, Bo,Zhang, Chunzhu,Wang, You,Zhu, Shaolin
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supporting information
p. 2328 - 2332
(2020/01/08)
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- Tailoring Interfacial Lewis Acid-Basic Pair on ZnO/4Mg1ZrOx Allows Dehydrogenative α-Methylenation of Alcohols with Methanol to Allylic Alcohols
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Allylic alcohols are the essential building blocks widely used in diverse streams of organic inventions for pharmaceuticals, fragrances, agrochemicals and polymers. Currently, allylic alcohols are industrially produced from petroleum-based feedstocks via atom uneconomic processes. More sustainable synthesis route for allylic alcohols is limited. Herein, a methodology for the direct and highly selective production of allylic alcohols has been accomplished by controlled dehydrogenative α-methylenation of alcohols with methanol. This transformation is enabled by interfacial Lewis acid-basic pair on tailor-made ZnO/4Mg1ZrOx mixed oxide. High selectivity (83～92%) of allylic alcohols is the consequence of alcohols acceptorless dehydrogenation to liberation of H2 and Meerwein-Ponndorf-Verley type hydrogen transfer onto C = O bonds of unsaturated aldehydes. Furthermore, the prepared ZnO/4Mg1ZrOx mixed oxide shows good stability after 200 h time on stream test. These observations could additionally allow us to design multifunctional solid acid-basic catalysts for the transformations of renewable oxygenates into value-added chemicals.
- Fu, Aixiao,Jiang, Shifeng,Liu, Qiang,Liu, Xiaoran,Liu, Xiuyun,Mu, Xindong,Sun, Mengqing,Wang, Xicheng,Xu, Guoqiang,Zhao, Lingling
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- Method for preparing methallyl alcohol by using in-situ generated Cu (I) catalyst
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The invention relates to a method for preparing methallyl alcohol by using an in-situ generated Cu (I) catalyst, which comprises the following steps: (1) dissolving a bivalent copper salt in water, adding a reducing organic matter, stirring, and dropwisely adding an obtained mixture into a methallyl alcohol preparation system; or (2) in themethallyl alcohol preparation system, adding thebivalent copper salt, then dropwise adding a reduced organic matter aqueous solution, and carrying out a catalytic reaction; or (3) in themethylallyl alcohol preparation system, adding a reduced organic matteraqueous solution, then dropwise adding a bivalent copper salt aqueous solution, and carrying out a catalytic reaction; or (4) mixing asolid bivalent copper salt with asolid reduced organic matter in proportion, adding an obtained mixture into themethallyl alcohol preparation system in batches, and carrying out catalytic reaction. The reaction system has the characteristics of high activity and high selectivity, can significantly improvethe conversion rate and selectivity of methylallyl alcohol, reducethe generation of by-product methylallyl ether, significantly reduces the synthesis cost by replacing monovalent copper with bivalent copper, and improve the market competitiveness.
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Paragraph 0030-0032
(2020/06/16)
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- Catalyst-controlled regioselective carbonylation of isobutylene oxide to pivalolactone
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Poly(pivalolactone) (PPVL) is a crystalline polyester with attractive physical and mechanical properties; however, prohibitively expensive syntheses of pivalolactone have thwarted efforts to produce PPVL on an industrial scale. Therefore, we developed a class of highly regioselective sandwich-type catalysts for the carbonylation of isobutylene oxide. These sterically encumbered complexes install carbon monoxide at the substituted epoxide carbon, generating a high level of contrasteric selectivity (up to >99:1). Further catalyst development improved catalyst solubility and reproducibility while maintaining high regioselectivity. In addition, a dibasic ester solvent extended catalyst lifetimes and suppressed side product formation. This contrasteric carbonylation of isobutylene oxide offers a route to sought-after pivalolactone and, therefore, PPVL.
- Hubbell, Aran K.,Lamb, Jessica R.,Klimovica, Kristine,Mulzer, Michael,Shaffer, Timothy D.,MacMillan, Samantha N.,Coates, Geoffrey W.
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p. 12537 - 12543
(2020/11/10)
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- Asymmetric Reductive and Alkynylative Heck Bicyclization of Enynes to Access Conformationally Restricted Aza[3.1.0]bicycles
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Conformationally restricted azabicycles are becoming increasingly important in medicinal research. Asymmetric Heck bicyclization of enynes proceeds to give medicinally useful aza[3.1.0] and aza[4.1.0] bicycles with excellent enantioselectivity. The key organopalladium species after bicyclization can be trapped by silanes and terminal alkynes.
- Chi, Yonggui Robin,Huang, Xiaolei,Nguyen, Minh Hieu,Pu, Maoping,Wu, Yun-Dong,Zhang, Luoqiang,Zhou, Jianrong Steve
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supporting information
p. 10814 - 10818
(2020/06/09)
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- Enantioselective Synthesis of 4-Allyl Tetrahydroquinolines via Copper(I) Hydride-Catalyzed Hydroallylation of 1,2-Dihydroquinolines
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CuCl/(R,R)-Ph-BPE-catalyzed asymmetric hydroallylation of 1,2-dihydroquinolines, prepared from readily available quinolines, was developed. The optically active tetrahydroquinolines (THQs) bearing an allylic functionality at position 4 were obtained in good yields and excellent enantioselectivity. The introduced allylic groups are amenable to diverse transformations, thus offering chances to rapidly expand the THQ libraries.
- Xu-Xu, Qing-Feng,You, Shu-Li,Zhang, Xiao
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supporting information
p. 1530 - 1534
(2020/03/13)
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- Magnetic Anchored CoPt Bimetallic Nanoparticles as Selective Hydrogenation Catalyst for Cinnamaldehyde
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Selective hydrogenation reaction of cinnamaldehyde is crucial for its appliction in fine chemical industries. The traditional noble metal catalyst for this reaction is expensive and often involving tedious steps. In this work, the magnetic anchored CoPt/Fe3O4 catalyst is prepared by a simple wet-impregnation method and evaluted as catalyst for selective hydrogenation of cinnamaldehyde. Electrons transfer directly from Co to Pt NPs can enhance H2 dissociation capability in the Co NPs interface, thereby strengthen the overall catalytic performance. Under optimum conditions, the conversion of cinnamaldehyde is 95% with 84% selectivity of cinnamyl alcohol. Furthermore, the magnetic interaction between the outer Co NPs and the Fe3O4 support maintains the stability of cinnamyl alcohol selectivity after repeated tests.
- Yuan, Tao,Liu, Derong,Pan, Yue,Pu, Xiaoqin,Xia, Yongde,Wang, Jinbo,Xiong, Wei
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p. 851 - 859
(2018/11/30)
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- A Ba/Pd Catalytic System Enables Dehydrative Cross-Coupling and Excellent E-Selective Wittig Reactions
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A Ba/Pd cooperative catalysis system was developed to enable the dehydrative cross-coupling of allylic alcohols with P-ylides to occur directly and promote a subsequent Wittig reaction in one pot. A variety of multisubstituted 1,4-dienes were isolated in good to excellent yields with broad P-ylides (stabilized by both ester and ketone carbonyl groups) and aldehyde (aliphatic and aromatic) substrates with excellent E selectivity.
- Xie, Peizhong,Fu, Weishan,Cai, Xinying,Sun, Zuolian,Wu, Ying,Li, Shuangshuang,Gao, Cuiqing,Yang, Xiaobo,Loh, Teck-Peng
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supporting information
p. 7055 - 7059
(2019/09/12)
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- Silver-promoted cascade radical cyclization of γ,δ-unsaturated oxime esters with P(O)H compounds: synthesis of phosphorylated pyrrolines
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A cascade radical cyclization was realized for the first silver-promoted imino-phosphorylation of γ,δ-unsaturated oxime esters, which provided a step-economical and redox-neutral route to access a variety of phosphorylated pyrrolines in good to excellent yields. Moreover, a new bulky trivalent phosphine ligand with a pyrroline motif was obtained through a deoxidation process.
- Chen, Chen,Bao, Yinwei,Zhao, Jinghui,Zhu, Bolin
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supporting information
p. 14697 - 14700
(2019/12/11)
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- Importance of the Nature of the Active Acid/Base Pairs of Hydroxyapatite Involved in the Catalytic Transformation of Ethanol to n-Butanol Revealed by Operando DRIFTS
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Operando DRIFTS is used to identify the nature and the role of the surface sites of hydroxyapatites (HAps) involved in the catalytic transformation of ethanol to n-butanol. The surface processes occurring upon a first reaction step followed by a step under He flow greatly influence the reactivity of HAps in a subsequent second reaction step. Ethanol is found to be mostly activated by the basic OH? groups of HAps, as indicated by the concomitant recovery of ethanol conversion and OH? groups under He flow. The drastic changes in selectivity observed during the second reaction step reveal the key role of acidic sites cooperatively acting with basic sites for basic reaction steps. Once the POH groups are poisoned by extensive formation of polymeric carbon species and the Ca2+ sites are available, the production of acetaldehyde is drastically promoted at the expense of that of n-butanol. It is concluded that i) acetaldehyde acts as an intermediate in the formation of n-butanol, and ii) various active sites are involved in the key basic reaction steps such as Ca2+?OH? and POH?OH? acid-base pairs in the dehydrogenation of ethanol to acetaldehyde and the aldol condensation for n-butanol formation, respectively.
- Osman, Manel Ben,Krafft, Jean-Marc,Thomas, Cyril,Yoshioka, Tetsuya,Kubo, Jun,Costentin, Guylène
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p. 1765 - 1778
(2019/02/26)
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- Interconverting Lanthanum Hydride and Borohydride Catalysts for C=O Reduction and C?O Bond Cleavage
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The high catalytic reactivity of homoleptic tris(alkyl) lanthanum La{C(SiHMe2)3}3 is highlighted by C?O bond cleavage in the hydroboration of esters and epoxides at room temperature. The catalytic hydroboration tolerates functionality typically susceptible to insertion, reduction, or cleavage reactions. Turnover numbers (TON) up to 10 000 are observed for aliphatic esters. Lanthanum hydrides, generated by reactions with pinacolborane, are competent for reduction of ketones but are inert toward esters. Instead, catalytic reduction of esters requires activation of the lanthanum hydride by pinacolborane.
- Patnaik, Smita,Sadow, Aaron D.
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supporting information
p. 2505 - 2509
(2019/02/01)
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- Development of a novel secondary phosphine oxide-ruthenium(II) catalyst and its application for carbonyl reduction
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A secondary phosphine oxide-phosphine mixed tridentate ligand and its ruthenium complex have been developed. This complex shows excellent catalytic activity for carbonyl reduction, especially for the reduction of α,β-unsaturated aldehydes. The turnover number and selectivity can reach up to 36500 and 99%, respectively. Control experiments and DFT calculations supported an outer-sphere mechanism during the hydrogenation reaction.
- Tan, Xuefeng,Zeng, Weijun,Zhang, Xiaoyong,Chung, Lung Wa,Zhang, Xumu
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supporting information
p. 535 - 538
(2018/01/19)
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- Rhodium-Catalyzed Synthesis of α,β-Unsaturated Ketones through Sequential C-C Coupling and Redox Isomerization
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A novel Rh(I)-catalyzed sequential C-C coupling and redox isomerization between allylic alcohols and 1,3-dienes has been accomplished. This versatile protocol provides expeditious access to a broad range of polysubstituted α,β-unsaturated ketones with excellent atom economy and regioselectivity.
- Li, Hong-Shuang,Guo, Guili,Zhang, Rui-Ze,Li, Fei
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supporting information
p. 5040 - 5043
(2018/08/24)
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- A 2 - synthesis of allylic alcohol (by machine translation)
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The invention relates to the field of organic synthetic technology, in particular to a 2 - synthesis of allylic alcohol, aimed at improving the product yield, reduce the content of impurity, and shorten the reaction time, so that the synthesis method is easy to industrialization. Its synthesis process mainly comprises the following steps: S1: water, solid alkali, a catalyst and a polymerization inhibitor is added in a reaction vessel, heating to 40 °C; S2: to the S1 obtained solution adds by drops 2 - propyl methallylloxy; S3: the S2 the solution obtained is heated to reflux, and fully reaction; S4: will be S3 resulting solution temperature reduction, layered, shall be organic and aqueous layer; S5: will be S4 obtained in the organic layer rectification, to obtain the target product. The technical proposal through the raw material 2 - propyl chlorine instillment methallylloxy in to the lye, and added to the reaction system in the aroma or [...] as a catalyst to promote 2 - propyl chlorine hydrolisis methallylloxy, greatly shorten the reaction time, and improve the product yield. (by machine translation)
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Paragraph 0034-0099
(2018/09/29)
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- Synthesis method of low-pollution 2-methallyl alcohol
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The invention relates to the technical field of organic synthesis, and particularly relates to a synthesis method of low-pollution 2-methallyl alcohol, aiming to improve the yield of the product, reducing impurities content, and shortening reaction time. The synthesis method is suitable for industrial production. The synthesis method mainly comprises the following steps of first, adding water, solid base, a catalyst and a polymerization inhibitor to a reaction container once, and heating to 45 DEG C; second, dropwise adding 2-methyl allyl chloride to the solution obtained in the first step; third, heating the solution obtained in the second step till the solution returns, and reacting fully; fourth, cooling the solution obtained in the third step, standing and layering to obtain an organiclayer and a water layer; and fifth, performing rectification on the organic layer obtained in the fourth step to obtain the target product. According to the synthesis method, the raw material 2-methyl allyl chloride is added dropwise to the alkali liquor, and acrylonitrile or acetonitrile is added to a reaction system to be used as a catalyst to promote hydrolyzation of 2-methyl allyl chloride, so that the reaction time is shortened greatly, and the yield of the product is increased.
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Paragraph 0034; 0035; 0036-0043; 0064; 0065; 0066-0093; 0099
(2018/10/19)
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- Environment-friendly synthetic method for 2-methylallyl alcohol
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The invention specifically relates to an environment-friendly synthetic method for 2-methylallyl alcohol, belonging to the technical field of organic synthesis. The objective of the invention is to improve product yield, reduce impurity contents, shorten reaction time and allow the synthetic method to be easily industrialized. The synthetic method mainly comprises the following steps: S1, adding water, a solid base, a catalyst and a polymerization inhibitor into a reaction vessel at a time and carrying out heating to 42 DEG C; S2, adding 2-methylallyl chloride into the solution obtained in thestep S1 drop by drop; S3, heating a solution obtained in the step S2 until reflux occurs and carrying out a sufficient reaction; S4, cooling a solution obtained in the step S3, and carrying out standing for layering so as to obtain an organic layer and an aqueous layer; S5, rectifying the organic layer obtained in the step S4 to obtain the target product. According to a technical scheme in the invention, the raw material 2-methylallyl chloride is added into an alkaline solution drop by drop, and acrylonitrile or acetonitrile is added into a reaction system as a catalyst to promote the hydrolysis of 2-methylallyl alcohol, so reaction time is greatly shortened and product yield is increased.
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Paragraph 0034-0040; 0044-0050; 0054-0060; 0064-0070
(2018/12/02)
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- Preparation process for 2-methylallyl alcohol
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The invention specifically relates to a preparation process for 2-methylallyl alcohol, belonging to the technical field of organic synthesis. The objective of the invention is to improve product yield, reduce impurity contents, shorten reaction time and allow the preparation process to be easily industrialized. The preparation process mainly comprises the following steps: S1, adding water, a solidbase, a catalyst and a polymerization inhibitor into a reaction vessel at a time and carrying out heating to 38 DEG C; S2, adding 2-methylallyl chloride into a solution obtained in the step S1 drop by drop; S3, heating a solution obtained in the step S2 until reflux occurs and carrying out a sufficient reaction; S4, cooling a solution obtained in the step S3, and carrying out standing for layering so as to obtain an organic layer and an aqueous layer; S5, rectifying the organic layer obtained in the step S4 to obtain the target product. According to a technical scheme in the invention, the raw material 2-methylallyl chloride is added into an alkaline solution drop by drop, and n-butyronitrile, propionitrile or cyanoacetylene is added into a reaction system as a catalyst to promote the hydrolysis of 2-methylallyl alcohol, so reaction time is greatly shortened and product yield is increased.
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Paragraph 0034-0099
(2018/12/02)
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- Industrialized production method of 2-methallyl alcohol
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The invention relates to the technical field of organic synthesis, in particular to an industrialized production method of 2-methallyl alcohol. The method aims at improving the product yield, reducingthe sundry content and shortening the reaction time, so that the synthesis method can easily realize industrialization. The synthesis process mainly comprises the following steps that S1, water, solid alkali, catalysts and polymerization inhibitors are added into a reaction container in one step; heating is performed to 35 DEG C; S2, 2-methyl allyl chloride is dropwise added into the solution obtained in S1; S3, the solution obtained in the S2 is heated until backflow is realized; full reaction is performed; S4, the solution obtained in S3 is subjected to temperature reduction; still standinglayering is performed; an organic layer and a water layer are obtained; S5, the organic layer obtained in S4 is rectified to obtain a target product. The technical scheme has the advantages that theraw materials of 2-methyl allyl chloride are dropwise added into alkali liquid; phenol or thiophenol is added into a reaction system as catalysts for promoting the hydrolysis of the 2-methyl allyl chloride; the reaction time is greatly shortened; the product yield is improved.
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Paragraph 0034-0097; 0099
(2018/12/13)
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- Stereoselective Synthesis of Pyrans from Epoxyalkenes: Dual Catalysis with Palladium and Br?nsted Acid
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We describe regio- and stereoselective cycloisomerizations of alcohols tethered to epoxyalkenes, to construct alkene-substituted pyrans. These transformations are best catalyzed by Pd(PPh3)4 in the presence of phosphite ligands, and with diphenylphosphinic acid as an essential Br?nsted acid cocatalyst for activation of the epoxyalkene.
- Setterholm, Noah A.,McDonald, Frank E.
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p. 6259 - 6274
(2018/05/29)
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- Preparation method of methylallyl alcohol
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The invention discloses a preparation method of methylallyl alcohol. The method is characterized in that the methylallyl alcohol and a carboxylate compound are obtained by adopting methylallyl chloride and carboxylate as raw materials and alcohol as a solvent. The solvent creatively adopts the alcohol, not an alkali or other solvents, so reaction conditions are mild, and the irritation to the rawmaterials is low; and more importantly, the carboxylate also can be obtained, the content of ether and salt products is low, the yield of the target product is high, so the method in the invention hasadvantages over traditional technologies characterized by adoption of the alkali as a hydrolysis agent, a two-step reaction and high byproduct content.
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Paragraph 0020-0021
(2018/06/04)
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- Method for simultaneously preparing methylallyl alcohol and cyclododecanone
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The invention provides a method for simultaneously preparing methylallyl alcohol and cyclododecanone. According to the method, cyclohexanol is adopted as a reducing agent to supply activity H, methylacrolein is reduced in the presence of a catalyst and a polymerization inhibitor to obtain methylallyl alcohol and cyclododecanone products. The process has the characteristics of high atom economy, high product yield, mild reaction condition and no pollution.
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Paragraph 0041; 0042; 0043; 0044; 0045; 0046; 0047--0055
(2017/08/25)
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- A Strategy for the Simultaneous Synthesis of Methallyl Alcohol and Diethyl Acetal with Sn-Β
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A new strategy was developed to simultaneously produce two important chemicals, namely, methallyl alcohol (Mol) and diethyl acetal (Dal) from methacrolein in ethanol solvent at low temperature with the use of Beta zeolites modified by tin (Sn-β catalysts). All the Sn-β catalysts were prepared by the solid-state ion-exchange method, wherein the calcination step was conducted under different gas atmospheres. The catalyst precalcined in Ar (Sn-β-Ar) had a reduced number of extra-framework Sn species and enabled more Sn species to be exchanged into the framework as isolated tetrahedral SnIV, enhancing the catalytic activity of the Meerwein–Ponndorf–Verley (MPV) reaction. The sodium-exchanged Sn-β-Ar, with a reduced number of weak Br?nsted acid sites, led to an even better selectivity for Mol, owing to the restriction of the side reactions such as acetalization, addition, and etherification. Under optimized catalyst and reaction conditions, the yield of Mol and Dal reached approximately 90 % and 96 %, respectively. The possible reaction pathways, along with a complex network of side products, was proposed after a detailed investigation through the use of different substrates as reactants. The fine-tuning of Sn-β catalysts through different treatments discussed in this work is of great significance toward the understanding and manipulation of complex reactions between α,β-unsaturated aldehydes and primary alcohols.
- Hu, Wenda,Wan, Yan,Zhu, Lili,Cheng, Xiaojie,Wan, Shaolong,Lin, Jingdong,Wang, Yong
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p. 4715 - 4724
(2017/12/15)
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- Method for preparing methallyl alcohol and amide simultaneously
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A method for preparing methallyl alcohol and amide simultaneously is characterized in that methylallyl carboxylate taken as a raw material and an amine compound taken as an ammonolysis agent react under the action of a catalyst to produce methallyl alcohol and an amide compound. The methylallyl carboxylate and the amine compound taken as the ammonolysis agent are firstly adopted, and the methallyl alcohol and the amide compound are obtained under the action of the catalyst. The reaction process is a bulk reaction, no solvents are added, almost no wastewater or salt are produced, and byproduct methyl allyl ether is not produced; the defect that a large number of wastewater is produced through hydrolysis is overcome due to adoption of ammonolysis, the methallyl alcohol and the amide compound are coproduced directly by use of ammonoysis, coupling production is realized, and the cost is reduced.
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Paragraph 0034-0035
(2017/11/29)
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- Preparation process of 2-methylallyl alcohol
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The invention discloses a novel process for preparing 2-methylallyl alcohol. The novel process comprises the following steps: taking 2-methylacrolein and aldehyde without a compound as shown in the specification as raw materials; carrying out crossed Cannizzaro disproportionated reaction under the catalysis effect to generate methylpropenyl carboxylate; and hydrolyzing the methylpropenyl carboxylate in an alkali metal hydroxide solution to generate the 2-methylallyl alcohol as the target product and sodium carboxylate as a co-product. Crossed Cannizzaro disproportionated reaction is carried out, aldol reaction is hardly carried out among molecules, by-products are few, and the generated product is high in conversion perent and good in selectivity; hydrolysis reaction is thorough in an alkaline environment, the yield of 2-methylallyl alcohol product is high, the 2-methylallyl alcohol is easily separated and purified, meanwhile, the carboxylate product is co-produced, and water in a hydrolysis reaction stage is totally recycled; reaction conditions are gentle, energy consumption is low, and atom economy is high; and the preparation process is simple in process, low in cost and environmentally friendly.
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Paragraph 0014
(2017/09/02)
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- A process for the preparation of trifluoromethylation of the
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The invention provides a preparation method of allyl alcohol. The preparation method comprises the steps of reacting acetaldehyde or propaldehyde with formaldehyde under the existence of a heterogeneous catalyst to obtain allyl aldehyde, wherein the allyl aldehyde is allyl aldehyde or methyl allyl aldehyde; reacting allyl aldehyde or methyl allyl aldehyde with hydrogen gas under the existence of a catalyst to obtain the allyl alcohol, wherein the allyl alcohol is allyl alcohol or 2-methyl allyl alcohol. The method has simple process, low cost, few byproducts, good selectivity and high yield.
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Paragraph 0089; 0094
(2017/03/14)
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- A 2-methyl propanol method for the preparation of
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The invention provides a preparation method for 2-methylallyl alcohol. The preparation method for 2-methylallyl alcohol comprises the following steps: oxidizing isobutene into 2-methylacrolein in the presence of a catalyst A, vapour and air; reducing 2-methylacrolein into 2-methylallyl alcohol in the presence of a catalyst B and hydrogen. Because of using isobutene as a starting material, selectively oxidizing isobutene into methylacrolein by a metallic oxide, and then directly performing a hydrogenation reaction to produce 2-methylallyl alcohol, the method is high in yield, low in cost, low in energy consumption, and environment-friendly and clean.
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Paragraph 0058; 0060
(2016/10/07)
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- Multi-scale promoting effects of lead for palladium catalyzed aerobic oxidative coupling of methylacrolein with methanol
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A highly efficient Pd2Pb8/alumina catalyst was prepared, which provided the highest turnover number (TON) of 302 for aerobic oxidative coupling of methylacrolein with methanol. The enhanced catalytic efficiency could be attributed to the multi-scale (micron, nano and atom scales) promoting effects of the pre-loaded Pb species. This journal is
- Han, Junxing,Zhang, Suojiang,Li, Yuchao,Yan, Ruiyi
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p. 2076 - 2080
(2015/04/14)
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- The method of producing alcohol Allylnaphthol (by machine translation)
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PROBLEM TO BE SOLVED: To provide a method which obtains an allyl alcohol compound useful as a raw material for synthesizing functional compounds such as drugs, agricultural chemicals and perfumes with high selectivity without performing complicated operations such as pH adjustment in the reaction system. SOLUTION: The process for producing an allyl alcohol compound comprises hydrolyzing an allyl halide compound in the presence of a basic compound and a monovalent copper compound in the atmosphere of carbon dioxide. COPYRIGHT: (C)2013,JPO&INPIT
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Paragraph 0019; 0020; 0022; 0023
(2016/12/01)
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- Core-shell AgNP@CeO2 nanocomposite catalyst for highly chemoselective reductions of unsaturated aldehydes
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Selective silver: A core-shell AgNP-CeO2 nanocomposite (AgNP@CeO2) acted as an effective catalyst for the chemoselective reductions of unsaturated aldehydes to unsaturated alcohols with H2 (see figure). Maximizing the AgNP-CeO2 interaction successfully induced the heterolytic cleavage of H2, resulting in highly chemoselective reductions. Furthermore, a highly dispersed AgNP@CeO2 system was also developed that exhibited a higher activity than the original AgNP@CeO2. Copyright
- Mitsudome, Takato,Matoba, Motoshi,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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supporting information
p. 5255 - 5258
(2013/05/22)
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- Remarkable effect of bases on core-shell AgNP@CeO2 nanocomposite-catalyzed highly chemoselective reduction of unsaturated aldehydes
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A highly dispersed coreshell silver nanoparticleceria nanocomposite catalyst (AgNP@CeO2-D) was prepared. The addition of bases was found to enhance the catalytic efficiency of AgNP@CeO2-D significantly in the chemoselective reduction of diverse unsaturated aldehydes to the corresponding unsaturated alcohols.
- Mitsudome, Takato,Matoba, Motoshi,Yamamoto, Masaaki,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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p. 660 - 662
(2013/07/05)
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- MONOMER COMPOSITION CONTAINING UNSATURATED POLYALKYLENE GLYCOL ETHER-BASED MONOMER, METHOD FOR PRODUCING COMPOSITION THEREOF, POLYMER OBTAINED USING COMPOSITION THEREOF, AND METHOD FOR PRODUCING POLYMER THEREOF
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To provide a monomer composition containing an unsaturated polyalkylene glycol ether-based monomer and having excellent stability. Provided is a monomer composition containing an unsaturated polyalkylene glycol ether-based monomer represented by the following chemical formula (1): [in-line-formulae]YO(R1O)nR2??(1)[/in-line-formulae] [in the formula, Y represents an alkenyl group having 2 to 7 carbon atoms; R1O represents one or two or more types of oxyalkylene groups having 2 to 18 carbon atoms; n represents an average addition mole number of oxyalkylene groups and is a number of 5 to 500; and R2 represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms], an organic acid, and water, and having a pH of 4 to 13.
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Page/Page column
(2013/07/25)
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- The effect of a unique halide-stabilizing residue on the catalytic properties of haloalkane dehalogenase DatA from Agrobacterium tumefaciens C58
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Haloalkane dehalogenases catalyze the hydrolysis of carbon-halogen bonds in various chlorinated, brominated and iodinated compounds. These enzymes have a conserved pair of halide-stabilizing residues that are important in substrate binding and stabilization of the transition state and the halide ion product via hydrogen bonding. In all previously known haloalkane dehalogenases, these residues are either a pair of tryptophans or a tryptophan-asparagine pair. The newly-isolated haloalkane dehalogenase DatA from Agrobacterium tumefaciens C58 (EC 3.8.1.5) possesses a unique halide-stabilizing tyrosine residue, Y109, in place of the conventional tryptophan. A variant of DatA with the Y109W mutation was created and the effects of this mutation on the structure and catalytic properties of the enzyme were studied using spectroscopy and pre-steady-state kinetic experiments. Quantum mechanical and molecular dynamics calculations were used to obtain a detailed analysis of the hydrogen-bonding patterns within the active sites of the wild-type and the mutant, as well as of the stabilization of the ligands as the reaction proceeds. Fluorescence quenching experiments suggested that replacing the tyrosine with tryptophan improves halide binding by 3.7-fold, presumably as a result of the introduction of an additional hydrogen bond. Kinetic analysis revealed that the mutation affected the substrate specificity of the enzyme and reduced its K0.5 for selected halogenated substrates by a factor of 2-4, without impacting the rate-determining hydrolytic step. We conclude that DatA is the first natural haloalkane dehalogenase that stabilizes its substrate in the active site using only a single hydrogen bond, which is a new paradigm in catalysis by this enzyme family. The newly-isolated haloalkane dehalogenase DatA from Agrobacterium tumefaciens C58 possesses a unique halide-stabilising tyrosine residue, Y109, in place of the conventional tryptophan. This is the first natural haloalkane dehalogenase that stabilises its substrate in the active site using only a single hydrogen bond, which is a new paradigm in catalysis by this enzyme family.
- Hasan, Khomaini,Gora, Artur,Brezovsky, Jan,Chaloupkova, Radka,Moskalikova, Hana,Fortova, Andrea,Nagata, Yuji,Damborsky, Jiri,Prokop, Zbynek
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p. 3149 - 3159
(2013/07/26)
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- An efficient synthesis of the fully elaborated isoindolinone unit of muironolide A
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An efficient stereocontrolled construction of the fully substituted isoindolone subunit of muironolide A is described. The approach is centered on the intramolecular Diels-Alder reaction between the enol form of the β-keto amide and an α,β,γ,δ-unsaturated ester, followed by the installation of the cyclohexene double bond.
- Xiao, Qing,Young, Kyle,Zakarian, Armen
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supporting information
p. 3314 - 3317
(2013/07/26)
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- Asymmetric syntheses of 8-oxabicyclo[3,2,1]octanes: A cationic cascade cyclization
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High octane: A novel and practical syntheses of 8-oxabicyclo[3.2.1]octanes using a cationic cascade cyclization reaction has been developed (see scheme; TIPS=triisopropylsilyl). The diastereomer of the cyclization product isolated depends upon whether the acetal or aldehyde substrate is used. Copyright
- Li, Bin,Zhao, Yu-Jun,Lai, Yin-Chang,Loh, Teck-Peng
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supporting information; experimental part
p. 8041 - 8045
(2012/09/05)
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- Studies on the biodegradation of fosfomycin: Synthesis of 13C-labeled intermediates, feeding experiments with rhizobium huakuii PMY1, and Isolation of Labeled Amino Acids from Cell Mass by HPLC
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Racemic (1R*,2R*)-1,2-dihydroxy-[1-13C 1]propylphosphonic acid and 1-hydroxy-[1-13C 1]acetone were synthesized and fed to R. huakuii PMY1. Alanine and a mixture of valine and methionine were isolated as their N-acetyl derivatives from the cell hydrolysate by reversed-phase HPLC and analyzed by NMR spectroscopy. It was found that the carbon atoms of the respective carboxyl groups were highly 13C-labeled (up to 65 %). Hydroxyacetone is therefore considered an obligatory intermediate of the biodegradation of fosfomycin by R. huakuii PMY1.
- McGrath, John W.,Hammerschmidt, Friedrich,Kaehlig, Hanspeter,Wuggenig, Frank,Lamprecht, Guenther,Quinn, John P.
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experimental part
p. 13341 - 13348
(2012/03/22)
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- Atomically precise Au25(SR)18 nanoparticles as catalysts for the selective hydrogenation of α,β-unsaturated ketones and aldehydes
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(Chemical equation presented) A golden opportunity: A mechanism has been proposed to account for the chemoselective hydrogenation of α,β- unsaturated ketones (or aldehydes) to unsaturated alcohols catalyzed by monodisperse Au25(SR)18 particles (see picture). Now that the structure of these nanoparticles is known, structure-activity correlations can be drawn.
- Zhu, Yan,Qian, Huifeng,Drake, Bethany A.,Jin, Rongchao
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supporting information; experimental part
p. 1295 - 1298
(2010/05/02)
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- SELECTIVE PREPARATION OF SOME 2-ALKOXY-ETHANOL DERIVATIVES
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A method for producing certain 2-alkoxy-ethanol derivatives by depolymerising oligomeric or polymeric polyglycol derivatives in the presence of alcoholate or 1,3-diketonate derivatives of zirconium, titanium, aluminium or molybdenum.
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Page/Page column 2; 3
(2010/08/08)
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- Facile photochemical transformation of alkyl aryl selenides to the corresponding carbonyl compounds by molecular oxygen: Use of selenides as masked carbonyl groups
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(Chemical Equation Presented) Alkyl aryl selenides with and without functional groups on the alkyl group were transformed efficiently into the corresponding carbonyl compounds, particulary primary alkyl aryl selenides in good yields, by a simple photolysis in the presence of air or oxygen. This transformation can be conducted without protection of functional groups. The yield of carbonyl compounds was much affected by the solvent viscosity, reaction temperature, concentration of dissolved oxygen in the solvents, wavelength of light, and structure of the aryl substituents. The present study indicates that aryl selenides can be considered as a masked carbonyl group that can be easily converted to a carbonyl group by very mild reaction conditions even in the presence of various unprotected functional groups. Therefore, this functional group transformation can be used as an important tool in organic synthesis due to its simplicity and mild reaction condition.
- Hyugano, Takeshi,Liu, Suyou,Ouchi, Akihiko
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supporting information; scheme or table
p. 8861 - 8866
(2009/04/05)
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- Selective pyrolysis of bifunctional compounds: gas-phase elimination of carbonate-ester functionalities
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Compounds containing both carbonate and ester functionalities were synthesized and then subjected to online-GC gas-phase pyrolysis. The carbonate groups were cleaved selectively in all elimination reactions. The end products of the reaction were found to be affected by the nature of the substrate. The presence of hydrogen and carbonyl substituents on the carbon β to the carbonate group resulted in further product decomposition through a concerted six-membered transition state. Results from flash vacuum pyrolysis (FVP) and analysis of the GC data indicate that the cleavage of the carbonate group is fast, and that the slower secondary decomposition reactions are independent of the presence of the carbonate group. Spectroscopic analyses of the products are reported.
- Al-Azemi, Talal F.,Dib, Hicham H.,Al-Awadi, Nouria A.,El-Dusouqui, Osman M.E.
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p. 4126 - 4134
(2008/09/20)
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- Mild and convenient method for reduction of carbonyl compounds with the NaBH4/charcoal system in wet THF
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The NaBH4/C (charcoal) system reduces a variety of carbonyl compounds such as aldehydes, ketones, acyloins and α-diketones to their corresponding alcohols in high to excellent yields. Reduction reactions were carried out in wet THF at r.t. In addition, regioselective 1,2-reduction of α,β-unsaturated aldehydes and ketones was achieved perfectly with this reducing system. By decreasing the amount of aprotic solvent, all reductions took place fast and efficiently under solid-gel condition.
- Setamdideh, Davood,Zeynizadeh, Behzad
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p. 1275 - 1281
(2008/09/18)
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