Lanthanide Amides [(Me3Si)2N]3Ln(μ-Cl)Li(THF)3 Catalyzed Hydrophosphonylation of Aryl Aldehydes

Rare Earth Amide-Catalyzed Direct Thioesterification of Aldehydes with Thiols under Mild Conditions

Direct thioesterification of aldehydes with thiols catalyzed by readily accessible rare earth/lithium amide RE[N(SiMe3)2]3(μ-Cl)Li(THF)3 is developed, which enables the preparation of a range of thioesters (31 examples) under room temperature and solvent-free conditions, without using any additive or external oxidant. This method provides a straightforward and atom-efficient approach for the thioester synthesis.

Sequential In Situ-Formed Kukhtin-Ramirez Adduct and P(NMe2)3-Catalyzed O-Phosphination of α-Dicarbonyls with P(O)-H

O-Phosphination of α-dicarbonyls via sequential in situ formation of a Kukhtin-Ramirez adduct and a P(NMe2)3-catalyzed process has been exploited for the synthesis of α-phosphoryloxy carbonyls. A range of P(O)-H derivatives, including diarylphosphine oxides, arylphosphinates, and phosphinates, are competent candidates to be introduced into the α-dicarbonyls in this transformation, and various α-phosphoryloxy carbonyls are obtained. This approach possesses advantages of mild conditions, simple operations, atom economy, high efficiency, and gram-scale synthesis, which make it promising in the synthesis toolbox.

Tunable vicinal, geminal diphosphorylation and C-N bond phosphorylation of enaminones toward divergent phosphorylated ketone derivatives

This paper reports the trifunctionalization reactions of tertiary enaminones in the fashion of selective gem- and vicinal diphosphorylation, leading to the tunable synthesis of α,α- and α,β-diphosphoryl ketones. In addition, the C-N bond phosphorylation with improved substrate tolerance has been achieved.

Lewis acid-catalyzed Pudovik reaction-phospha-Brook rearrangement sequence to access phosphoric esters

Herein, we report a Lewis acid-catalyzed Pudovik reaction-phospha-Brook rearrangement sequence between diarylphosphonates or -phosphinates and α-pyridinealdehydes to access valuable phosphoric ester compounds. This transformation provides an extended substrate scope that is complementary to similar previously reported base-catalyzed transformations.

Enzyme Inhibition Properties and Molecular Docking Studies of 4-Sulfonate Containing Aryl α-Hydroxyphosphonates Based Hybrid Molecules

In this study, a series of new hybrid molecules containing two important functional groups on the same skeleton were designed. 4-Hydroxybenzaldehyde and its two different derivatives were converted into their respective sulphonates by interacting with tosylchloride and methanesulfonyl chloride. Then, the desired molecules were synthesized by adding diethoxyphosphonate to the aldehyde group. Also, novel synthesis of hybrid compounds (4a-c and 5a-c) were tested toward some metabolic enzymes like carbonic anhydrase I and II isoenzymes (hCA I and hCA II) and acetylcholinesterase (AChE) enzyme. The synthesis of hybrid compounds (4a-c and 5a-c) showed K_i values of in range of 25.084±4.73-69.853±15.19 nM against hCA I, 32.325±1.67-82.761±22.73 nM against hCA II and 1.699±0.25 and 3.500±0.91 nM against AChE. For these compounds, compound 4c showed maximum inhibition effect against hCA I and hCA II isoenzymes and compound 5b showed maximum inhibition effect against AChE enzyme. By performing docking studies of the most active compounds for their binding modes and interactions were determined.

Recent advances in the carbon-phosphorus (C-P) bond formation from unsaturated compounds by s- and p-block metals

Researchers around the globe have witnessed several breakthroughs in s- and p-block metal chemistry. Over the past few years, several applications in catalysis associated with these main group metals have been established, and owing to their abundance and low cost and they have proved to be essential alternatives to transition metal catalysts. In this review, we present a detailed discussion on the catalytic addition of P-H bonds from various phosphine reagents to multiple bonds of unsaturated substrates for the synthesis of organophosphorus compounds with C-P bonds promoted by various s- and p-block metal catalysts, as published in the last decade.

Lanthanide Silylamide-Catalyzed Synthesis of Pyrano[2,3-b]indol-2-ones

A lanthanide silylamide-catalyzed tandem reaction of isatins, diethyl phosphite, and 2,3-diarylcyclopropenones has been developed. A series of pyrano[2,3-b]indol-2-ones were synthesized in high yields. The cooperation of the Lewis acidity of the lanthanide center and the Bronsted basicity of the N(SiMe₃)₂ anion may be the key factor affecting the catalytic activity of lanthanide amides.

Trivalent Rare-Earth Metal Amide Complexes as Catalysts for the Hydrosilylation of Benzophenone Derivatives with HN(SiHMe2 )2 by Amine-Exchange Reaction

The rare-earth metal complexes Ln(L1 )[N(SiHMe2 )2 ](thf) (Ln=La, Ce, Y; L1 =N,N''-bis(pentafluorophenyl)diethylenetriamine dianion) were synthesized by treating Ln[N(SiHMe2 )2 ]3 (thf)2 with L1 H2 . The lanthanum and cerium derivatives are active catalysts for the hydrosilylation of benzophenone derivatives with HN(SiHMe2 )2 . An amine-exchange reaction was revealed as a key step of the catalytic cycle, in which Ln-Si-H β-agostic interactions are proposed to promote insertion of the carbonyl moiety into the Si-H bond.

Ultrasound for Drug Synthesis: A Green Approach

This last century, the development of new medicinal molecules represents a real breakthrough in terms of humans and animal life expectancy and quality of life. However, this success is tainted by negative environmental consequences. Indeed, the synthesis of drug candidates requires the use of many chemicals, solvents, and processes that are very hazardous, toxic, energy consuming, expensive, and generates a large amount of waste. Many large pharmaceutical companies have thus moved to using green chemistry practices for drug discovery, development, and manufacturing. One of them is the use of energy-efficient activation techniques, such as ultrasound. This review summarizes the latest most representative works published on the use of ultrasound for sustainable bioactive molecules synthesis.

Catalyst-free synthesis of α1-oxindole-α-hydroxyphosphonates via phospha-aldol reaction of isatins employing N-heterocyclic phosphine (NHP)-thiourea

A catalyst-free phospha-aldol reaction of isatins with NHP-thiourea has been developed and the critical role of the Brønsted acid in this transformation is unveiled.

2-Oxo promoted hydrophosphonylation & aerobic intramolecular nucleophilic displacement reaction

Highly efficient catalyst free methods for the synthesis of α-hydroxy-β-oxo phosphonates (HOP) and α-oxoesters (OE) have been described for the first time. The existence of a 2-oxo group in α-oxoaldehydes (OA) was a key factor in promoting the reaction of the tervalent phosphite form towards activated aldehydes (OA) in the synthesis of HOP.

Amido rare-earth complexes supported by an ansa bis(amidinate) ligand with a rigid 1,8-naphthalene linker: synthesis, structures and catalytic activity in rac-lactide polymerization and hydrophosphonylation of carbonyl compounds

We report the synthesis of rare-earth amides and their catalytic activity in ROP of lactide.

Stereogenic phosphorus-induced diastereoselective formation of chiral carbon during nucleophilic addition of chiral H-P species to aldehydes or ketones

P,C-stereogenic α-hydroxyl phosphinates or phosphine oxides were prepared from the additions of (RP)-phosphinate to ketones or (RP)-phosphine oxide to aldehydes, respectively, catalyzed by bases at room temperature in up to >99:1 diasteromeric ratio (d.r.P/d.r.C) and 99 % yields. The diastereoselectivity was induced by reversible equilibrium and different stabilities between two diastereomers of adduct, which was caused by the spatial interaction between menthoxyl or menthyl to alkyl groups of aldehydes or ketones.

Addition of optically pure H-phosphinate to ketones: selectivity, stereochemistry and mechanism

A stability-controlled diastereoselective addition of a chiral P–H species to ketones afforded P,C-stereogenic α-hydroxyphosphinates in excellent yields and dr.