10385-30-5Relevant academic research and scientific papers
In situ generation of o-lodoxybenzoic acid (IBX) and the catalytic use of it in oxidation reactions in the presence of oxone as a co-oxidant
Thottumkara, Arun P.,Bowsher, Michael S.,Vinod, Thottumkara K.
, p. 2933 - 2936 (2005)
(Chemical Equation Presented) Catalytic use of o-iodoxybenzoic acid (IBX) in the presence of Oxone as a co-oxidant is demonstrated for the oxidation of primary and secondary alcohols in user- and eco-friendly solvent mixtures. Also demonstrated is the in situ (re)oxidation of 2-iodosobenzoic acid (IBA) and even commercially available 2-iodobenzoic acid (2IBAcid) by Oxone to IBX allowing one to use these less hazardous reagents, in place of potentially explosive IBX, as catalytic oxidants.
(P(C6H5)3)CpRu+-catalyzed deprotection of allyl carboxylic esters
Kitamura, Masato,Tanaka, Shinji,Yoshimura, Masahiro
, p. 4975 - 4977 (2002)
A new and efficient catalytic method for deprotection of allyl carboxylic esters using a transition metal complex is reported. The reaction proceeds with a high substrate/catalyst ratio and without use of additional nucleophiles, giving the deprotected carboxylic acid in a quantitative yield. A variety of substrates, including the multifunctional amino acids and peptides, are also usable. The new method is more efficient, safe, and operationally simple in comparison to the conventional palladium-catalyzed method.
Electrostatic complexation and photoinduced electron transfer between Zn-Cytochrome c and polyanionic fullerene dendrimers
Braun, Martin,Atalick, Stefan,Guldi, Dirk M.,Lanig, Harald,Brettreich, Michael,Burghardt, Stephan,Hatzimarinaki, Maria,Ravanelli, Elena,Prato, Maurizio,Van Eldik, Rudi,Hirsch, Andreas
, p. 3867 - 3875 (2003)
Two dendritic fullerene (DF) monoadducts, 2 and 3, which can carry up to 9 and 18 negative charges, respectively, were examined with respect to electrostatic complexation with Cytochrome c (Cytc). To facilitate comprehensive photophysical investigations,
An expedient strategy towards an advanced pyrrolidine intermediate for the synthesis of pyrrolizidine alkaloids
Bera, Smritilekha,Mondal, Dhananjoy,Chatterjee, Bhaskar
, p. 1260 - 1262 (2015)
The asymmetric synthesis of a new pyrrolidine intermediate and a preceding amino triol derivative was accomplished using Crimmins' modified Evans aldol reaction as the key step. The synthetically useful pyrrolidine intermediate is expected to serve as the immediate precursor of biologically important pyrrolizidine alkaloids (-)-isoretronecanol and (-)-cremastrine. In addition, the amino triol subunit acts as a useful intermediate for the synthesis of oxocane heterocycles.
A Novel Synthesis of Sex Pheromone from the Longicorn Beetle (Psacothea hilaris)
He, Guo-Guo,Rao, Bao-Qi,Zhang, Tao,Zhang, Hong-Li,Bai, Hongjin,Du, Zhen-Ting
, p. 455 - 461 (2021/04/13)
Abstract: An asymmetric synthesis of (8Z,21R)-21-methylpentatriacont-8-ene, the sex pheromoneof the yellow-spotted longicorn beetle Psacotheahilaris, has been achieved using Evan’s induction as the keystep. Based on the asymmetric methylation product of chiral (R)-4-benzyl-1,3-oxazolidin-2-one, the carbon chainof the target molecule was assembled through aC5+C12+C11+C8sequence. (2R)-4-(Benzyloxy)-2-methylbutan-1-ol, which can be obtained fromγ-lactone following Evan’s protocol, was connected to aC12 alkyl group. The chiral methyl group remained thekey moiety (97% ee). After another Wittigreaction and catalytic hydrogenation step, the designed key intermediate(13R)-13-methylheptacosan-1-ol wasobtained. Finally, after oxidation and Wittig reaction, the synthesis of thetarget molecule was completed in 10 linear steps with an ultra-high overallyield of 36.2%.
Suppressing carboxylate nucleophilicity with inorganic salts enables selective electrocarboxylation without sacrificial anodes
Corbin, Nathan,Lazouski, Nikifar,Manthiram, Karthish,Steinberg, Katherine,Yang, Deng-Tao
, p. 12365 - 12376 (2021/10/08)
Although electrocarboxylation reactions use CO2as a renewable synthon and can incorporate renewable electricity as a driving force, the overall sustainability and practicality of this process is limited by the use of sacrificial anodes such as magnesium and aluminum. Replacing these anodes for the carboxylation of organic halides is not trivial because the cations produced from their oxidation inhibit a variety of undesired nucleophilic reactions that form esters, carbonates, and alcohols. Herein, a strategy to maintain selectivity without a sacrificial anode is developed by adding a salt with an inorganic cation that blocks nucleophilic reactions. Using anhydrous MgBr2as a low-cost, soluble source of Mg2+cations, carboxylation of a variety of aliphatic, benzylic, and aromatic halides was achieved with moderate to good (34-78%) yields without a sacrificial anode. Moreover, the yields from the sacrificial-anode-free process were often comparable or better than those from a traditional sacrificial-anode process. Examining a wide variety of substrates shows a correlation between known nucleophilic susceptibilities of carbon-halide bonds and selectivity loss in the absence of a Mg2+source. The carboxylate anion product was also discovered to mitigate cathodic passivation by insoluble carbonates produced as byproducts from concomitant CO2reduction to CO, although this protection can eventually become insufficient when sacrificial anodes are used. These results are a key step toward sustainable and practical carboxylation by providing an electrolyte design guideline to obviate the need for sacrificial anodes.
Synthesis method of sex pheromone (S)-14-methyl-1-octadecene of lepidoptera pest peach leaf miners
-
Paragraph 0047; 0049-0050, (2020/08/02)
The invention discloses a synthesis method of a sex pheromone (S)-14-methyl-1-octadecene of peach leaf miners, which comprises the following steps: carrying out ring opening on gamma-butyrolactone asa raw material, reacting the gamma-butyrolactone with benzyl chloride to generate 4-benzyloxybutyric acid, and reacting the 4-benzyloxybutyric acid with (S)-4-benzyl-2-oxazolidinone; performing reaction with methyl iodide under the action of organic base to induce chiral methyl; reducing the chiral methyl into alcohol under the action of lithium aluminum hydride, oxidizing the alcohol into aldehyde, and carrying out wittig reaction with triphenylpropylphosphonium bromide; after the Wittig reaction, using a Pt/C as a catalyst for catalytic hydrogenation to remove double bonds, removing benzyl with Pd/C as a catalyst to form alcohol, and oxidizing the alcohol into aldehyde; carrying out monobromination on 1, 10-decanediol, carrying out single protection by using TBSCl, and performing reaction with triphenylphosphine to obtain quaternary phosphonium salt; carrying out Wittig reaction on the aldehyde and the quaternary phosphonium salt, and using Pt/C as a catalyst for catalytic hydrogenation to eliminate double bonds; removing TBS single protection to form alcohol, and then oxidizing the alcohol into aldehyde; and reacting the aldehyde with methyltriphenylphosphonium bromide wittig toobtain the pheromone (S)-14-methyl-1-octadecene. According to the method, the reaction conditions are mild, chiral methyl is kept in the reaction process, and racemization is avoided.
Asymmetric total synthesis method of sex pheromone (R, Z)-21-methyl-8-tripentadecene of psacothea hilaris
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Paragraph 0048; 0059, (2020/12/30)
The invention discloses an asymmetric total synthesis method of sex pheromone (R, Z) 21-methyl-8-tripentadecene of psacothea hilaris, the method comprises the following steps: by using a compound 14 as an initial raw material, assembling a molecular carbon chain according to the sequence of C5+C12+C11+C8; firstly carrying out Wittig reaction with C12 quaternary phosphonium salt, and then carryingout another Wittig reaction and catalytic hydrogenation to obtain the key intermediate (R)-13-methylheptanoic acid-1-alcohol. Finally, after primary oxidation and Wittig reaction, obtaining the sex pheromone of the psacothea hilaris, wherein the total yield is 36.2%. According to the invention, the problems of lengthy synthesis steps, difficult resolution and low yield of non-chiral raw materialsin chiral pheromone synthesis are solved, and the asymmetric total synthesis of the sex pheromone (R,Z)21-methyl-8-tripentadecene of psacothea hilaris is completed. The method has the advantages of high yield, simple and convenient chemical operation and competitiveness in the aspect of cost control.
Oxidation of Alkynyl Boronates to Carboxylic Acids, Esters, and Amides
Li, Chenchen,Li, Ruoling,Zhang, Bing,Zhao, Pei,Zhao, Wanxiang
supporting information, p. 10913 - 10917 (2020/05/25)
A general efficient protocol was developed for the synthesis of carboxylic acids, esters, and amides through oxidation of alkynyl boronates, generated directly from terminal alkynes. This protocol represents the first example of C(sp)?B bond oxidation. This approach displays a broad substrate scope, including aryl and alkyl alkynes, and exhibits excellent functional group tolerance. Water, primary and secondary alcohols, and amines are suitable nucleophiles for this transformation. Notably, amino acids and peptides can be used as nucleophiles, providing an efficient method for the synthesis and modification of peptides. The practicability of this methodology was further highlighted by the preparation of pharmaceutical molecules.
Stereoselective synthesis of the Paulownia bagworm sex pheromone
Sun, Zhi-Feng,Zhou, Lu-Nan,Zhang, Tao,Du, Zhen-Ting
, p. 558 - 562 (2017/06/19)
According to our retrosynthesis, the main chain of the target molecule could be constructed using a C5?+?C7?+?C5 strategy. The key induction reaction afforded chiral methyl group moieties using different Evans templates with different configurations. Li2CuCl4 was effectively employed in the Csp3[sbnd]Csp3 coupling protocol. The target molecular was obtained in a 12.6% overall yield with nine steps in the longest linear route.
