Aldehydes In Excellent Yields Research Articles

One-Pot, Catalyst-Free Synthesis of Nitriles from Aldehydes Using Aminating Reagent MsONH3OTf

AbstractAn eco-friendly protocol to synthesize nitriles from their corresponding aromatic and aliphatic aldehydes in excellent yields has been developed. This is a catalyst-free protocol which employs an aminating reagent (MsONH3OTf) under mild conditions. The hydroxylamine triflic acid salts (MsONH3OTf) acted as the N source for this protocol. Our protocol proved to be easy to perform and presented good functional group tolerance.

Anchored Ni‐dimethylglyoxime complex on Fe3O4@SiO2 core/shell nanoparticles for the clean catalytical synthesis of dicoumarols

Ni‐Dimethylglyoxime complex immobilized on functionalized Fe3O4 was synthesized by a post‐grafting way and utilized as a novel, thermally stable, recoverable, and efficient for green synthesis of dicoumarols through reaction of 4‐hydroxycoumarin with various aldehydes in excellent yields and higher rate. Fe3O4@SiO2‐silylcyclopropyl‐dimethylglyoxime‐Ni superparamagnetic nanoparticles (MNPs) were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X‐ray spectroscopy, X‐ray diffraction, vibrating sample magnetometer, and Brunauer–Emmett–Teller technique. This nanocatalyst could be conveniently recovered via the use of an external magnetic field and reused for subsequent reactions for at least 7 times without any remarkable change and decrease in catalytic activity.

Dicoumarol derivatives: Green synthesis and molecular modelling studies of their anti-LOX activity

Dicoumarol derivatives were synthesized in the InCl3 catalyzed pseudo three-component reactions of 4-hydroxycoumarin with aromatic aldehydes in excellent yields. The reactions were performed in water under microwave irradiation. All synthesized compounds were characterized using NMR, IR, and UV–Vis spectroscopy, as well as with TD-DFT. Obtained dicoumarols were subjected to evaluation of their in vitro lipid peroxidation and soybean lipoxygenase inhibition activities. It was shown that five of ten examined compounds (3e, 3h, 3b, 3d, 3f) possess significant potential of antilipid peroxidation (84–97%), and that compounds 3b, 3e, 3h provided the highest soybean lipoxygenase (LOX-Ib) inhibition (IC50 = 52.5 µM) and 3i somewhat lower activity (IC50 = 55.5 µM). The bioactive conformations of the best LOX-Ib inhibitors were obtained by means of molecular docking and molecular dynamics. It was shown that, within the bioactive conformations interior to LOX-Ib active site, the most active compounds form the pyramidal structure made of two 4-hydroxycoumarin cores and a central phenyl substituent. This form serves as a spatial barrier which prevents LOX-Ib Fe2+/Fe3+ ion activity to generate the coordinative bond with the C13 hydroxyl group of the α-linoleate. It is worth pointing out that the most active compounds 3b, 3e, 3h and 3i can be candidates for further examination of their in vitro and in vivo anti-inflammatory activity and that molecular modeling study results provide possibility to screen bioactive conformations and elucidate the mechanism of dicoumarols anti-LOX activity.

Copper diisobutyl-t-butoxyaluminum hydride: A novel reagent for chemoselective reduction of tertiary amides over esters

We demonstrate that copper diisobutyl-t-butoxyaluminum hydride, readily prepared from lithium diisobutyl-t-butoxyaluminum hydride and CuI, effectively and chemoselectively reduces tertiary amides over esters at ambient temperature, affording the corresponding aldehydes in excellent yields.

Stereoselective synthesis of indenone-fused heterocyclic compounds via a one-pot four-component reaction

A one-pot multi-component synthesis of indenone-fused heterocyclic derivatives from readily available starting materials including diamines, 1,1-bis(methylthio)-2-nitroethene, 1,3-indandione and aromatic aldehydes in excellent yields is described. The sequence of cascade reactions include Knoevenagel condensation, enamine formation, Michael addition, imine-enamine tautomerization and cyclization. The diastereoselective synthesis of cis-indenohydropyridine have been definitively proven by X-ray crystallography.

Dual Catalysis for the Aerobic Oxidation of Benzyl Alcohols – Nitric Acid and Fluorinated Alcohol

Benzyl alcohols were oxidized with oxygen to aldehydes in excellent yields with high selectivities at room temperature. Dual catalysis was operative with HNO3 as the oxidant and precursor of the nitrogen oxides and with the use of 1,1,1,3,3,3‐hexafluoro‐2‐propanol as a template catalyst and solvent. Fluorinated alcohols also increased the selectivity by inhibiting further oxidation to benzoic acids. Activation of nitric acid catalyzed aerobic oxidation by the fluorinated solvent made the use of 2,2,6,6‐tetramethylpiperidin‐1‐oxyl (TEMPO) or a metal catalyst superfluous.

Fe+3-Montmorillonite K10, as effective, eco-friendly, and reusable catalyst for the synthesis of bis(1H-indol-3-yl)methanes under grinding condition

Bis(indoyl)methanes have been synthesized via electrophilic reaction of indole and aldehydes in excellent yields under mild reaction conditions in the presence of Fe+3-montmorillonite K10 as catalyst. The catalyst can be recovered and recycled in subsequent reactions without any apparent loss of activity.

Base-free direct formylation of aromatic iodides using CO2 as C1 source catalyzed by palladium nanoparticles grafted onto amino-functionalized nanostarch

Highly dispersed Pd-nanoparticles grafted onto amino-functionalized nanostarch were found to be excellent heterogeneous catalysts for the direct formylation of various aromatic iodides to their corresponding aldehydes in excellent yields without using any base. The developed catalyst could easily be recovered and recycled for several runs without any significant loss in activity and importantly, no metal leaching was occurred during the reaction.

Efficient and mild cyclization procedures for the synthesis of novel 2-amino-4H-pyran derivatives with potential antitumor activity

Abstract A series of novel 2-amino-4 H -pyran derivatives have been synthesized via a three-component reaction of α , β -unsaturated ketone derivatives, malononitrile, aldehydes in excellent yields, using DBU as a catalyst and ethanol as a cheap, safe, and environmentally benign solvent under mild conditions. Their antitumor activity was evaluated in three human tumor cell lines, including human colon cancer (HCT116), human cervical cancer (Hela), and non-small cell lung cancer (H1975).

ChemInform Abstract: Cu‐NHC‐TEMPO Catalyzed Aerobic Oxidation of Primary Alcohols to Aldehydes.

Imidazolium salts bearing TEMPO groups react with commercially available copper powder affording Cu-NHC complexes. The in situ generated Cu-NHC-TEMPO complexes are quite efficient catalysts for aerobic oxidation of primary alcohols into aldehydes. The catalyst is easily available, and various primary alcohols were selectively converted to aldehydes in excellent yields.

ChemInform Abstract: Solvent‐Controlled Copper‐Catalyzed Oxidation of Benzylic Alcohols to Aldehydes and Esters.

A procedure for the copper-catalyzed selective oxidation of primary alcohols to esters and aldehydes was developed. Under solvent-free conditions, self-oxidative esterification and cross-esterification of benzyl alcohols with various aliphatic alcohols proceed smoothly to give the corresponding esters in good yields. If DMF was used as a solvent, the benzyl alcohols were selectively converted into the corresponding aldehydes in excellent yields.

A Novel Organocatalytic Asymmetric Transfer Hydrogenation of α,β‐Unsaturated Aldehydes

Abstractα,β‐Unsaturated aldehydes reacted with diimide (diazene) in the presence of optically active ammonium salt 1 as a catalyst to give the corresponding saturated aldehydes in excellent yields and up to 98 : 2 er. Attractive features of the asymmetric transfer hydrogenation are its high yields, and chemo‐, and enantioselectivities.

ChemInform Abstract: Molecular Assembly of an Achiral Phosphine and a Chiral Primary Amine: A Highly Efficient Supramolecular Catalyst for the Enantioselective Michael Reaction of Aldehydes with Maleimides.

A combined catalyst system of a cinchonidine-derived primary amine and triphenylphosphine (CDNH 2 /PPh 3 ) exhibited high catalytic performance in the Michael reaction of aldehydes with maleimides, thereby affording the corresponding functionalized aldehydes in excellent yields (up to 99%) and enantioselectivities (>99% ee). More interestingly, the significance of the phosphine in enhancing the enantioselectivities in the chiral-primary-amine-catalyzed Michael reaction was revealed. Furthermore, we explored the origin of the reaction mechanism in the Michael addition promoted by the dual organocatalytic system. On the basis of experimental results and spectroscopic analysis, such as UV/Vis, fluorescence emission (FL), NMR, and circular dichroism (CD) spectroscopy, as well as ESI-MS, we found that the molecular assembly of phosphine and primary amine played a crucial role in this enantioselective reaction, in which a possible supramolecular complex was formed as an effective chiral catalyst through noncovalent molecular interactions of a cinchona alkaloid-derived primary amine with triphenylphosphine.

Oxidation of Primary Alcohols to Aldehydes with N-Halamine-Containing Polymers

Polymeric N-halamines have been previously employed for organic reactions such as sulfide oxidation. In the present study, we employed polymeric N-halamines to oxidize primary alcohols selectively to the corresponding aldehydes in excellent yields. After reaction, the polymers can be recycled and then reused for the next reaction process.

Cu-NHC-TEMPO Catalyzed Aerobic Oxidation of Primary Alcohols to Aldehydes

Imidazolium salts bearing TEMPO groups react with commercially available copper powder affording Cu-NHC complexes. The in situ generated Cu-NHC-TEMPO complexes are quite efficient catalysts for aerobic oxidation of primary alcohols into aldehydes. The catalyst is easily available, and various primary alcohols were selectively converted to aldehydes in excellent yields.

Highly efficient synthesis of aryl and heteroaryl trifluoromethyl ketones via o-iodobenzoic acid (IBX)

A two-step process for the synthesis of aryl and heteroaryl trifluoromethyl ketones from the corresponding aldehydes is described. Trifluoromethyl alcohols were prepared from aryl and heteroaryl aldehydes in excellent yields using catalytic amount of K2CO3. The trifluoromethyl alcohols were then oxidized conveniently and efficiently by o-iodoxybenzoic acid (IBX) under mild conditions to get the desired functionalized aryl and heteroaryl trifluoromethyl ketones.

Solvent‐Controlled Copper‐Catalyzed Oxidation of Benzylic Alcohols to Aldehydes and Esters

AbstractA procedure for the copper‐catalyzed selective oxidation of primary alcohols to esters and aldehydes was developed. Under solvent‐free conditions, self‐oxidative esterification and cross‐esterification of benzyl alcohols with various aliphatic alcohols proceed smoothly to give the corresponding esters in good yields. If DMF was used as a solvent, the benzyl alcohols were selectively converted into the corresponding aldehydes in excellent yields.

Molecular Assembly of an Achiral Phosphine and a Chiral Primary Amine: A Highly Efficient Supramolecular Catalyst for the EnantioselectiveMichael Reaction of Aldehydes with Maleimides

A combined catalyst system of a cinchonidine-derived primary amine and triphenylphosphine (CD-NH2 /PPh3 ) exhibited high catalytic performance in the Michael reaction of aldehydes with maleimides, thereby affording the corresponding functionalized aldehydes in excellent yields (up to 99 %) and enantioselectivities (>99 % ee). More interestingly, the significance of the phosphine in enhancing the enantioselectivities in the chiral-primary-amine-catalyzed Michael reaction was revealed. Furthermore, we explored the origin of the reaction mechanism in the Michael addition promoted by the dual organocatalytic system. On the basis of experimental results and spectroscopic analysis, such as UV/Vis, fluorescence emission (FL), NMR, and circular dichroism (CD) spectroscopy, as well as ESI-MS, we found that the molecular assembly of phosphine and primary amine played a crucial role in this enantioselective reaction, in which a possible supramolecular complex was formed as an effective chiral catalyst through noncovalent molecular interactions of a cinchona alkaloid-derived primary amine with triphenylphosphine.

A highly asymmetric direct aldol reaction catalyzed by chiral proline amide – thiourea bifunctional catalysts

A series of chiral proline amide – thiourea bifunctional catalysts derived from l-proline and chiral diamine were prepared and successfully applied to highly enantioselective direct aldol reactions of cyclohexanone with various aldehydes in excellent yields (85%–97%), diastereoselectivities (anti/syn > 20:1) and enantioselectivities (up to 91% ee).

Unexpected lactonization accompanying addition of ethyl acetoacetate to chalcones derived from 3-acetylthiophene

Chalcone derivatives containing thiophene ring were prepared by the condensation of 3-acetylthiophene with aromatic aldehydes in excellent yields. The addition of ethyl acetoacetate to chalcone derivatives 3a–3h in the presence of solid NaOH in CH2Cl2 resulted in the formation of the mixture of bicyclic lactone derivatives 5a–5h and 6-(ethoxycarbonyl)cyclohexenone derivatives 6a–6h.