Nano ceria catalyzed synthesis of α-aminophosphonates under ultrasonication

A simple, efficient and general method has been developed for the one-pot three component syntheses of α-aminophosphonates. The condensation of aldehyde, amine and triethyl phosphite by employing CeO₂ nanoparticles as catalyst gave α-aminophosphonates. The catalyst showed good recyclability. Nano CeO₂ has been found to be an excellent catalyst for the green synthesis of α-aminophosphonates under ultrasound irradiation and solvent-free condition. The α-aminophosphonates are obtained in good to excellent yield. This catalyst provides cleaner conversion, short reaction time and high selectivity which makes the protocol feasible and economical attractive.     

A facile synthesis of α-aminophosphonates catalyzed by ytterbium perfluorooctanoate under solvent-free conditions

Three-component reactions of aldehydes, amines and diethyl phosphite are efficiently catalyzed by ytterbium perfluorooctanoate [Yb(PFO)₃] under solvent-free conditions, giving the corresponding α-aminophosphonates in good to excellent yields. The catalyst can be recovered and reused for several times without any significant loss of activity. Furthermore, a possible mechanism for this transformation is also presented.     

One-pot three-component Kabachnik-Fields synthesis of α-aminophosphonates using H-beta zeolite catalyst

One-pot three-component Kabachnik-Fields synthesis of α-aminophosphonates with high yields from the reaction between carbonyl compound, primary amine, and substituted phosphite can be carried out in a short period, using H-beta zeolite as a reusable catalyst.     

One-pot three-component synthesis of α-amino nitriles catalyzed by nano powder TiO_2 P 25

A simple and efficient method has been developed for the synthesis ofα-amino nitriles from aldehydes,amines and trimethylsilyl cyanide（Me₃SiCN） in the presence of a catalytic amount of cyanuric acid at room temperature.     

Aluminium nitride catalyzed solvent-free synthesis of some novel biologically active α-aminophosphonates

A green and atom-efficient one-pot protocol for the synthesis of some novel α-aminophosphonates using micron-particulate AlN/Al as a new reusable heterogeneous catalyst by the Kabachnik–Fields reaction under solvent-free conditions has been developed. The synthesized α-aminophosphonates were screened for several biological activities. They all were investigated to exhibit moderate to promising antioxidant, anti-inflammatory and cytotoxic properties.     

Organocatalytic synthesis of α-hydroxy and α-aminophosphonates

A new and highly flexible procedure is described for the synthesis of α-amino- and α-hydroxy phosphonates. In the presence of a catalytic amount of oxalic acid (10 mol %), trimethyl phosphite reacts with aldehydes or imines (generated in situ from an aldehyde and an amine) to yield the corresponding coupled products in good yield.     

BINOL-based azacrown ether catalyzed enantioselective Michael addition: asymmetric synthesis of α-aminophosphonates

Several novel 1,1′-bi-2-naphthyl-appended azacrown ethers with donor side-arms were synthesized and applied for the first time as chiral catalysts in the asymmetric Michael addition of an N-protected aminomethylenephosphonate onto acrylonitriles, resulting in high diastereoselectivity and enantioselectivity. The absolute configuration of the adduct was determined from its experimental and calculated CD spectra.     

Efficient one-pot synthesis of α-aminophosphonates from aldehydes and ketones catalyzed by ytterbium(III) triflate

An efficient three component one-pot synthesis of N-silylated α-aminophosphonates and α,α-disubstituted α-aminophosphonates was developed using Yb(OTf)₃ as a catalyst at room temperature under mild conditions.     

Asymmetric synthesis of α-alkyl α-selenocarbonyl compounds catalyzed by bifunctional organocatalysts

A new organocatalytic approach for the synthesis of a variety of α-alkyl, α-phenylselenyl ketones as well as their corresponding esters and amides, by the addition of α-selenocarbonyl derivatives to nitroalkenes catalyzed by thiourea or squaramide cinchona catalysts, is presented. This catalytic system allows the preparation in high yields of enantiomerically enriched selenocarbonyl derivatives bearing two chiral centers with excellent ee's and dr's by using catalytic loadings of 3 mol%.     

Nano Gd2O3 catalyzed synthesis and anti-oxidant activity of new α-aminophosphonates

A one pot three-component nano Gd₂O₃ catalyzed neat reaction of 2-morpholinoethanamine and dimethylphosphite with various salicylaldehydes under microwave irradiation afforded a series of new α-aminophosphonates in high yields. The synthesized compounds were characterized by FT-IR, (¹H, ¹³C, ³¹P)-NMR, and mass spectral methods. The antioxidant activity of these compounds was evaluated against DPPH, NO, and H₂O₂ methods and found that the compound Dimethyl (2-hydroxy-5-nitrophenyl) (2-morpholinoethylamino) methylphosphonate (4h) has higher antioxidant activity than the corresponding standards.     

Convenient synthesis of α-diarylmethylphosphonates by HOTf catalyzed Friedel-Crafts arylation of α-aryl α-hydroxyphosphonates

We report a convenient catalytic Friedel-Crafts arylation of α-aryl α-hydroxyphosphonates with various (hetero)aromatic compounds. HOTf (trifluoromethanesulfonic acid) is identified to be the best Brønsted acid catalyst, and the desired α-diarylmethylphosphonates were obtained in up to 41–95% yield.     

A catalyst-free synthesis of α-aminophosphonates in glycerol

A simple and efficient method is described using glycerol as a solvent in the catalyst-free synthesis of α-aminophosphonates in high purity. Products are prepared by the Kabachnik–Fields reaction from amines, phosphites, and carbonyl compounds. The method does not require a toxic catalyst.     

Neat synthesis and antioxidant activity of α-aminophosphonates

A simple, efficient, and environmentally benign method for a three-component reaction of an amine, an aldehyde and diethyl phosphite catalyzed by Amberlyst-15 has been developed to afford α-amino phosphonates in high yields and short reaction times under solvent-free reaction conditions using microwave irradiation. The major advantages of the present method are inexpensive, ecofriendly and reusable catalyst and also studied their antioxidant activity of synthesized compounds.     

Mandelic acid catalyzed one-pot three-component synthesis of α-aminonitriles and α-aminophosphonates under solvent-free conditions at room temperature

Abstract

A simple, mild, straightforward, efficient and eco-friendly protocol has been developed for the synthesis of a series of α-aminonitriles via the one-pot three-component Strecker reactions between various aldehydes, amines and trimethylsilyl cyanide using a catalytic amount of mandelic acid as a naturally occurring, low-cost, efficient organo-catalyst under solvent-free conditions at room temperature. Under the same optimized conditions synthesis of α-aminophosphonates were also achieved via the one-pot three-component Kabachnik-Fields reactions of aldehydes, amines and triethyl phosphate.     

Microwave-assisted synthesis of α-aminophosphonates with sterically demanding α-aryl substituents

Abstract

A series of N-benzhydryl protected α-aminophosphonates with α-phenyl, α-(1-naphtyl), α-(9-anthryl) or α-(1-pyrenyl) substituents was synthesized by the Kabachnik–Fields condensation of diphenylmethylamine (benzhydrylamine), the corresponding aryl aldehyde and a dialkyl phosphite under MW irradiation. X-ray studies performed at low temperatures for a few of these α-aminophosphonates confirmed the presence of unusually short intramolecular C_α–H^δ+ ··· ^δ+H–C_peri contacts.     

One-pot synthesis of 1-amidoalkyl-2-naphthols catalyzed by nano-BF3·SiO2

1-Amidoalkyl-2-naphthols were prepared via one-pot multi-component reaction of 2-naphthol, aldehydes, and amides in the presence of nano-silica supported boron trifluoride (nano-BF₃·SiO₂) in ethyl acetate at 80 °C. Short reaction times, high yields, scaleup and easy work-up are the advantages of this protocol.     

Convenient synthesis of fluoroalkyl α- and β-aminophosphonates

Addition of both alkyl phosphites and phosphonate α-carbanions to N-substituted aldimines derived from fluoroalkyl aldehydes presents a convenient method for synthesis of fluoroalkyl α- and β-aminophosphonates in good yield (55-86%) under mild conditions.     

Palladium acetate-catalysed one-pot green synthesis of bis α-aminophosphonates

Research on Chemical Intermediates - A simple and effective green method has been developed for the synthesis of a series of novel bis α-aminophosphonate derivatives (4a–j) by the...     

One-pot asymmetric synthesis of α-trifluoromethylated amines from α-trifluoromethyl ketones

Diastereoselective reduction of (Rs)-N-tert-butanesulfinyl α-trifluoromethyl ketimines formed in situ from the corresponding α-trifluoromethyl ketones and N-tert-butanesulfinamide has been achieved, and either diastereomer of N-tert-butanesulfinyl α-trifluoromethyl amines was obtained in good yields with excellent diastereoselectivities (up to 99:1 dr) using NaBH₄ and L-Selectride as the reductants, respectively.