507-70-0Relevant articles and documents
A New, Highly Stereoselective Reducing Agent, Potassium 9-(2,3-Dimethyl-2-butoxy)-9-boratabicyclononane
Brown, Herbert C.,Cha, Jin Soon,Nazer, Behrooz
, p. 2073 - 2074 (1984)
A new reagent, potassium 9-(2,3-dimethyl-2-butoxy)-9-boratabicyclononane (K9-OThx-9-BBNH), achieves highly stereoselective reductions of cyclic ketones with very simple recovery of the product.
Ruthenium complexes of phosphine-amide based ligands as efficient catalysts for transfer hydrogenation reactions
Yadav, Samanta,Vijayan, Paranthaman,Yadav, Sunil,Gupta, Rajeev
, p. 3269 - 3279 (2021/03/16)
This work presents three mononuclear Ru(ii) complexes of tridentate phosphine-carboxamide based ligands providing a NNP coordination environment. The octahedral Ru(ii) ion shows additional coordination with co-ligands; CO, Cl and CH3OH. All three Ru(ii) complexes were thoroughly characterized including their crystal structures. These Ru(ii) complexes were utilized as catalysts for the transfer hydrogenation of assorted carbonyl compounds, including some challenging biologically relevant substrates, using isopropanol as the hydrogen source. The binding studies illustrated the coordination of the isopropoxide ion by replacing a Ru-ligated chloride ion followed by the generation of the Ru-H intermediate that was isolated and characterized and was found to be involved in the catalysis.
Poisoning effect of N-containing compounds on performance of Raney nickel in transfer hydrogenation
Martyanov, Oleg N.,Philippov, Alexey A.
, (2021/10/19)
The effect of amines, imines and heterocycle compounds on conversion has been studied in transfer hydrogenation of camphor and 2-PrOH catalyzed by Raney nickel. Small amount (5 mol% to nickel) of N-containing compound significantly decreases catalyst activity. It has been shown that the poisoning effect mostly depends on molecular size of amines and heterocyclic compounds. For aniline and cyclohexylamine the dependence of camphor conversion on poison/nickel ratio was obtained. Additionally, benzaldehyde, cinnamaldehyde demonstrated higher reactivity compared corresponding imines under transfer hydrogenation conditions. Obtained data explain low activity of nickel-based catalysts when N-containing compounds are presented in reaction mixture.
Simple Plug-In Synthetic Step for the Synthesis of (?)-Camphor from Renewable Starting Materials
Calderini, Elia,Drienovská, Ivana,Myrtollari, Kamela,Pressnig, Michaela,Sieber, Volker,Schwab, Helmut,Hofer, Michael,Kourist, Robert
, p. 2951 - 2956 (2021/06/18)
Racemic camphor and isoborneol are readily available as industrial side products, whereas (1R)-camphor is available from natural sources. Optically pure (1S)-camphor, however, is much more difficult to obtain. The synthesis of racemic camphor from α-pinene proceeds via an intermediary racemic isobornyl ester, which is then hydrolyzed and oxidized to give camphor. We reasoned that enantioselective hydrolysis of isobornyl esters would give facile access to optically pure isoborneol and camphor isomers, respectively. While screening of a set of commercial lipases and esterases in the kinetic resolution of racemic monoterpenols did not lead to the identification of any enantioselective enzymes, the cephalosporin Esterase B from Burkholderia gladioli (EstB) and Esterase C (EstC) from Rhodococcus rhodochrous showed outstanding enantioselectivity (E>100) towards the butyryl esters of isoborneol, borneol and fenchol. The enantioselectivity was higher with increasing chain length of the acyl moiety of the substrate. The kinetic resolution of isobornyl butyrate can be easily integrated into the production of camphor from α-pinene and thus allows the facile synthesis of optically pure monoterpenols from a renewable side-product.
Enantioselective Construction of Modular and Asymmetric Baskets
Badji?, Jovica D.,Finnegan, Tyler J.,Gunther, Michael J.,Pavlovi?, Radoslav Z.,Wang, Xiuze
supporting information, p. 25075 - 25081 (2021/10/25)
The precise positioning of functional groups about the inner space of abiotic hosts is a challenging task and of interest for developing more effective receptors and catalysts akin to those found in nature. To address it, we herein report a synthetic methodology for preparing basket-like cavitands comprised of three different aromatics as side arms with orthogonal esters at the rim for further functionalization. First, enantioenriched A (borochloronorbornene), B (iodobromonorbornene), and C (boronorbornene) building blocks were obtained by stereoselective syntheses. Second, consecutive A-to-B and then AB-to-C Suzuki–Miyaura (SM) couplings were optimized to give enantioenriched ABC cavitand as the principal product. The robust synthetic protocol allowed us to prepare (a) an enantioenriched basket with three benzene sides and each holding either tBu, Et, or Me esters, (b) both enantiomers of a so-called “spiral staircase” basket with benzene, naphthalene, and anthracene groups surrounding the inner space, and (c) a photo-responsive basket bearing one anthracene and two benzene arms.
Efficient catalytic transfer hydrogenation reactions of carbonyl compounds by Ni(II)-diphosphine complexes
Venkatesh, Sadhana,Panicker, Rakesh R.,Lenin Kumar, Verdhi,Pavankumar,Viswanath, Nukala,Singh, Shangrila,Desikan, Rajagopal,Sivaramakrishna, Akella
, p. 2963 - 2977 (2020/11/03)
The catalytic transfer hydrogenation reactions of a series of aromatic and aliphatic carbonyl compounds were investigated using divalent Ni(II)-diphosphine complexes, [L2NiCl2] (where L2 = 1,1-bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,1-bis(diphenylphosphino)ferrocene (dppf), and N-butyl-N-(diphenylphosphino)-1,1-diphenylphosphinamine (dppba)). This is a single-step reaction in the presence of potassium hydroxide and isopropyl alcohol to afford the corresponding alcohols. This protocol tolerates other sensitive functional groups like olefinic double bonds and also achieves high chemoselectivity. All the reactions were monitored by GC and GC–MS. The plausible mechanism is also discussed. The method reported in the present article is simple, cost-effective, and provides excellent conversions. Nickel-diphosphine complexes appear as a potential alternative to expensive transition metal complexes.
Molecular cloning and functional characterization of a two highly stereoselective borneol dehydrogenases from Salvia officinalis L
Drienovská, Ivana,Kolanovi?, Dajana,Chánique, Andrea,Sieber, Volker,Hofer, Michael,Kourist, Robert
, (2020/01/11)
Enzymes for selective terpene functionalization are of particular importance for industrial applications. Pure enantiomers of borneol and isoborneol are fragrant constituents of several essential oils and find frequent application in cosmetics and therapy. Racemic borneol can be easily obtained from racemic camphor, which in turn is readily available from industrial side-streams. Enantioselective biocatalysts for the selective conversion of borneol and isoborneol stereoisomers would be therefore highly desirable for their catalytic separation under mild reaction conditions. Although several borneol dehydrogenases from plants and bacteria have been reported, none show sufficient stereoselectivity. Despite Croteau et al. describing sage leaves to specifically oxidize one borneol enantiomer in the late 70s, no specific enzymes have been characterized. We expected that one or several alcohol dehydrogenases encoded in the recently elucidated genome of Salvia officinalis L. would, therefore, be stereoselective. This study thus reports the recombinant expression in E. coli and characterization of two enantiospecific enzymes from the Salvia officinalis L. genome, SoBDH1 and SoBDH2, and their comparison to other known ADHs. Both enzymes produce preferentially (+)-camphor from racemic borneol, but (?)-camphor from racemic isoborneol.
Monoterpenoid-based inhibitors of filoviruses targeting the glycoprotein-mediated entry process
Baev, Dmitriy S.,Maksyutov, Rinat A.,Mordvinova, Ekaterina D.,Pyankov, Oleg V.,Salakhutdinov, Nariman F.,Shcherbakov, Dmitriy N.,Shcherbakova, Nadezhda S.,Sokolova, Anastasiya S.,Tolstikova, Tatyana G.,Yarovaya, Olga I.,Zaykovskaya, Anna V.,Zybkina, Anastasiya V.
, (2020/09/09)
In this study, we screened a large library of (+)-camphor and (?)-borneol derivatives to assess their filovirus entry inhibition activities using pseudotype systems. Structure-activity relationship studies revealed several compounds exhibiting submicromolar IC50 values. These compounds were evaluated for their effect against natural Ebola virus (EBOV) and Marburg virus. Compound 3b (As-358) exhibited the good antiviral potency (IC50 = 3.7 μM, SI = 118) against Marburg virus, while the hydrochloride salt of this compound 3b·HCl had a strong inhibitory effect against Ebola virus (IC50 = 9.1 μM, SI = 31) and good in vivo safety (LD50 > 1000 mg/kg). The results of molecular docking and in vitro mutagenesis analyses suggest that the synthesized compounds bind to the active binding site of EBOV glycoprotein similar to the known inhibitor toremifene.
Method for synthesizing (+)-borneol by using imidazole acidic ionic liquid
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Paragraph 0008-0011, (2020/11/22)
The invention discloses a method for synthesizing (+)-borneol by using imidazole acidic ionic liquid, which comprises the following steps: synthesizing an intermediate from N-butyl imidazole and 1,4-butane sultone by using toluene as a solvent, washing with ethyl acetate, drying, and reacting the dried product with concentrated sulfuric acid to obtain the imidazole acidic ionic liquid catalyst that is 1-sulfobutyl-3-butyl imidazole bisulfate; applying the catalyst to alpha-pinene esterification saponification reaction to obtain (+)-borneol with high selectivity. According to the imidazole acidic ionic liquid, the selectivity of (+)-borneol can be improved without introducing other types of cocatalysts, the catalytic effect is stable, the preparation method of the ionic liquid as a catalystis simple, the period is short, the separation of the catalyst and a product can be realized by standing, and the catalyst is convenient to recycle.
Application of acidic ionic liquid in high-selectivity synthesis of n-borneol (by machine translation)
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Paragraph 0011-0014, (2020/11/22)
The invention discloses an application of acidic ionic liquid in high-selectivity synthesis of n-borneol, which takes toluene as a solvent and N - methylimidazole, 1,4 - butenolide synthesis intermediate and reacts with ethyl ether to react with concentrated sulfuric acid to prepare the acidic ionic liquid catalyst 1 - sulfobutyl -3 - methylimidazolium bisulfate [HSO]. 3 (CH)2 )4 - Mimim] [HSO4 The method changes the current situation that the selectivity of borneol is improved by introducing chloroacetic acid or the like as a co-catalyst, and ionic liquid is used as a catalyst to improve the selectivity of the borneol. (by machine translation)
