3446-90-0Relevant articles and documents
Base-Catalysed Hydrogenation of Sulphur-Containing Aldehydes
Vu, Thi-Thu-Ha,Kumbhar, Pramod S.,Figueras, Francois
, p. 493 - 496 (2003)
The present work reports the first selective catalytic hydrogenation of bifunctional compounds containing a carbonyl and sulphur moieties, using hydrogen transfer from alcohols and a basic catalyst. The reaction was performed in batch at 371 K at atmospheric pressure with 3- mercaptopropionaldehyde, thiophene-2-carboxaldehyde, 5-bromothiophene-2- carboxaldehyde and 4-methylthiobenzaldehyde. The only product of reaction was the alcohol, formed with yields > 80%, except with 3-mercaptopropionaldehyde which did not give the alcohol but rather afforded unidentified heavy products. 5-Bromothiophenemethanol was obtained with 100% yield in 3 h. The reaction obeys a mechanism of competitive adsorption of the reactants, and the reaction rates are higher than those reported for supported rhodium catalysts.
Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
supporting information, p. 3723 - 3728 (2021/04/07)
We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
Reduction over Condensation of Carbonyl Compounds through a Transient Hemiaminal Intermediate Using Hydrazine
Vilches-Herrera, Marcelo,Gallardo-Fuentes, Sebastián,Aravena-Opitz, Mauricio,Yá?ez-Sánchez, Mauricio,Jiao, Haijun,Holz, Jens,B?rner, Armin,Lühr, Susan
, p. 9213 - 9218 (2020/08/14)
Reduction of carbonyl moieties to the corresponding alcohol using simply hydrazine hydrate has been considerably unfeasible until now due to the well-known condensation reaction. However, herein, we report that using an excess of 20-fold equivalents, the reduction proceeds in excellent yields. 1H NMR study of the reaction and density functional theory (DFT) calculations indicate that the final fate of the hemiaminal intermediate is crucial to obtain the alcohol or the hydrazone.
Synthetic Strategy for Tetraphenyl-Substituted All-E-Carotenoids with Improved Molecular Properties
Chung, Wook-Jin,Jung, Hyunuk,Koo, Sangho,Lim, Boram,Park, Myeongnam,Yang, Huijeong,Yoo, Hyebin
supporting information, (2020/03/13)
The synthetic method of tetraphenyl-substituted all-E-carotenes 1 with improved properties of antioxidant and molecular electronic conductance was developed through the formation of tetraphenyl-substituted all-E-apocarotenedial 4. The synthesis highlighted the preparation of novel subunits containing phenyl substituent(s) with E-configuration starting from the key (E)-4-chloro-2-phenylbut-2-enal (10), utilizing conjugation effect with formyl group or easy recrystallization of sulfone compounds. Sulfone-mediated coupling methods of Julia and modified Julia–Kocienski olefinations utilizing the subunits were demonstrated to produce tetraphenyl-substituted apocarotenedials 4. The major all-E-forms (73–85 % selectivity) were easily purified by SiO2 chromatography and trituration with Et2O due to the presence of the polar formyl groups. The olefination of all-E-apocarotenedials 4 and Wittig salt 5 provided all-E-9,9',13,13'-tetraphenylcarotenes 1.
BORON CONTAINING COMPOUNDS AND THEIR USES
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Paragraph 0314; 0315, (2020/03/29)
The present disclosure contemplates novel boron-containing compounds and their uses as active agents that exhibit pesticidal activity such as antimicrobial, insecticidal, arachnicidal, and/or anti parasitic activity. An agrochemical composition containing such a compound and its use in, animal health, agriculture, or horticulture is also contemplated. A method for promoting plant performance and/or controlling, reducing, preventing, ameliorating, or inhibiting microbes, insects, arachnids, and/or parasites on or in an animal, a plant, a plant part, plant propagation material, and/or harvested fruits or vegetables is also contemplated.
Regio- A nd chemoselective deprotection of primary acetates by zirconium hydrides
Gavel, Marine,Courant, Thibaut,Joosten, Antoine Yvan Philippe,Lecourt, Thomas
supporting information, p. 1948 - 1952 (2019/04/10)
A combination of DIBAL-H and Cp2ZrCl2 is shown to promote the regioselective cleavage of primary acetates on a broad scope of substrates, ranging from carbohydrates to terpene derivatives, with a high tolerance toward protecting groups and numerous functionalities found in natural products and bioactive compounds. Apart from providing highly valuable building blocks in only two steps from biosourced raw materials, this selective de-O-acetylation should also be strongly helpful to solve selectivity issues in organic synthesis.
Polypyridyl iridium(III) based catalysts for highly chemoselective hydrogenation of aldehydes
Pandrala, Mallesh,Resendez, Angel,Malhotra, Sanjay V.
, p. 283 - 288 (2019/09/30)
Iridium-catalyzed transfer hydrogenation (TH) of carbonyl compounds using HCOOR (R = H, Na, NH4) as a hydrogen source is a pivotal process as it provides the clean process and is easy to execute. However, the existing highly efficient iridium catalysts work at a narrow pH; thus, does not apply to a wide variety of substrates. Therefore, the development of a new catalyst which works at a broad pH range is essential as it can gain a broader scope of utilization. Here we report highly efficient polypyridyl iridium(III) catalysts, [Ir(tpy)(L)Cl](PF6)2 {where tpy = 2,2′:6′,2′'-Terpyridine, L = phen (1,10-Phenanthroline), Me2phen (4,7-Dimethyl-1,10-phenanthroline), Me4phen (3,4,7,8-Tetramethyl-1,10-phenanthroline), Me2bpy (4,4′-Dimethyl-2–2′-dipyridyl)} for the chemoselective reduction of aldehydes to alcohols in aqueous ethanol and sodium formate as the hydride source. The reaction can be carried out efficiently in broad pH ranges, from pH 6 to 11. These catalysts are air stable, easy to prepare using commercially available starting materials, and are highly applicable for a wide range of substrates, such as electron-rich or deficient (hetero)arenes, halogens, phenols, alkoxy, ketones, esters, carboxylic acids, cyano, and nitro groups. Particularly, acid and hydroxy groups containing aldehydes were reduced successfully in basic and acidic reaction conditions, demonstrating the efficiency of the catalyst in a broad pH range with high conversion rates under microwave irradiation.
General and Phosphine-Free Cobalt-Catalyzed Hydrogenation of Esters to Alcohols
Shao, Zhihui,Zhong, Rui,Ferraccioli, Raffaella,Li, Yibiao,Liu, Qiang
supporting information, p. 1125 - 1130 (2019/10/22)
Catalytic hydrogenation of esters is essential for the sustainable production of alcohols in organic synthesis and chemical industry. Herein, we describe the first non-noble metal catalytic system that enables an efficient hydrogenation of non-activated esters to alcohols in the absence of phosphine ligands (with a maximum turnover number of 2391). The general applicability of this protocol was demonstrated by the high-yielding hydrogenation of 39 ester substrates including aromatic/aliphatic esters, lactones, polyesters and various pharmaceutical molecules.
Ruthenium-Catalyzed Deaminative Hydrogenation of Aliphatic and Aromatic Nitriles to Primary Alcohols
Molnár, István Gábor,Calleja, Pilar,Ernst, Martin,Hashmi, A. Stephen K.,Schaub, Thomas
, p. 4175 - 4178 (2017/10/09)
The deaminative hydrogenation of nitriles towards alcohols is a useful reaction to transform nitriles into alcohols with NH3 as the sole byproduct. Using the simple and robust RuHCl(CO)(PPh3)3 complex as a catalyst, at low H2 pressures a series of aliphatic and aromatic nitriles could be transformed into the corresponding alcohols. Suitable solvent systems for these reactions were 1,4-dioxane/water and EtOH/water mixtures. In most cases, the selectivity for the alcohols was excellent, and the corresponding amines were formed only in trace amounts.
Cyclopentadienyl-ruthenium(II) complexes as efficient catalysts for the reduction of carbonyl compounds
Cabrita, Ivania R.,Florindo, Pedro R.,Fernandes, Ana C.
, p. 1511 - 1516 (2017/02/18)
This work reports the reduction of a large variety of aldehydes and ketones with the system PhSiH3/[CpRu(PPh3)2Cl] in good to excellent yields and high chemoselectivity. The catalyst [CpRu(PPh3)2Cl] can be used in at least 12 catalytic cycles with excellent catalytic activity and several substrates were reduced under solvent free conditions.
