Multigram Synthesis of Difluoromethylene Phosphonic and Phosphinic Amides and Phosphine Oxides via Formal [2,3]-Sigmatropic Allyl Phosphite – Allylphosphonate Rearrangement

Synthesis ◽  
2021 ◽  
Author(s):  
Mykhailo Shevchuk ◽  
Gerd-Volker Röschenthaler
Keyword(s):  
Phosphine Oxide ◽  
Carbonyl Compounds ◽  
Building Blocks ◽  
Phosphoryl Group ◽  
Phosphine Oxides ◽  
One Pot ◽  
Wittig Rearrangement ◽  
Material Chemistry ◽  
Derivatives Of

We describe a method for the preparation of CF2-P(V) building blocks and monomers for biological and material chemistry applications in multigram quantities based on a formal [2,3]-sigmatropic phospha-Wittig rearrangement of readily available fluoroallyl bis(amido)phosphites, amido(aryl)phosphonites and diarylphosphinites. The proposed intramolecular phosphorylation approach complements the currently prevailing phosphoryldifluoromethylation methods by providing a straightforward access to difluoromethylene phosphonate analogues bearing dialkylamino and/or aryl substituents at the phosphoryl group. An important advantage of the developed method is that it does not rely on ozone-depleting HCF2Cl and CF2Br2 necessary for the preparation of phosphoryldifluoromethylating reagents. 2,3,3-Trifluoroallyloxy P(III) derivatives substituted with two dialkylamino and/or aryl groups underwent a facile [2,3]-phospha-Wittig rearrangement to give difluoromethylene phosphonic, phosphinic and phosphine oxides on up to a 0.15 mol (30 g) scale. The reaction was extended to P(III) derivatives of 1-substituted 2,3,3-trifluoro- and 3,3-difluoroallylic alcohols readily available from carbonyl compounds and, respectively, 1,1,1,2-tetrafluoroethane and O-protected 2,2,2-trifluoroethanols. Products derived from O-(2-tetrahydropyranyl)-2,2,2-trifluoroethanol were synthesized and deprotected in a one-pot multistep protocol to give phosphonic, phosphinic and phosphine oxide analogues of α,α-difluoro-β-ketophosphonates on a multigram scale.

Three-component 3-(phosphoryl)methylindole synthesis from indoles, H-phosphine oxides and carbonyl compounds under metal-free conditions

2019 ◽  
Vol 21 (4) ◽  
pp. 792-797 ◽  
Author(s):  
Jiaoting Pan ◽  
Runmin Zhao ◽  
Jiami Guo ◽  
Dumei Ma ◽  
Ying Xia ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Indole Derivatives ◽  
Phosphine Oxides ◽  
One Pot ◽  
Metal Free ◽  
Three Component Reaction ◽  
Acid Catalyzed

The first facile and efficient acid-catalyzed three-component reaction of indoles, H-phosphine oxides and carbonyl compounds has been developed, providing a general, one-pot approach to structurally diverse C3-alkylated indole derivatives.

Recent Progress on Synthesis and Bio-activities of Tetrahydropyrimidine-2-one derivatives

2021 ◽  
pp. 221-228
Author(s):  
Mayur S. Bhosale ◽  
K. Sarvanan ◽  
N. S. Dighe
Keyword(s):  
Biginelli Reaction ◽  
Building Blocks ◽  
Liquid Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
National Library ◽  
Pharmacological Activities ◽  
One Pot ◽  
Nmr Spectrometry ◽  
Derivatives Of

This review covers up synthesis, characterization and Pharmacological activities of various derivatives of 1,2,3,4-Tetrahydropyrimidine-2-one, including recent mechanistic advances, new building blocks and new pharmacological disclosures. Tetrahydropyrimidines (THPs) are one of the most important systems among the heterocycles. These compounds reported to have less toxicity to human and animals. Various synthesis strategies have been reported for different derivatives of Tetrahydropyrimidines, mainly these involves Biginelli reaction (condensation) consisting of one pot synthesis of 1,2,3,4-Tetrahydropyrimidine derivatives using urea, β-keto ester and aldehyde. These derivatives also forms important part as intermediate in the manufacture of various Pharmaceuticals. Techniques such as infrared spectroscopy, liquid chromatography-mass spectrometry, 1H NMR and 13C NMR spectrometry along with single crystal X-ray diffraction has been reported for structural characterization of these derivatives. U.S. National Library of Medicines, NIH and European PMC have reported many these derivatives. Some of derivatives have reported to have promising anti-bacterial, cytotoxic, antifungal, anti-inflammatory activities. Recently Ultrasound and Microwave promoted synthesis has shown promising results in synthesis of these derivatives. Many exciting prospects await for its exploitation in this fields.

Structural analysis of 3-C-phosphonates, -phosphinates, and -phosphine oxides of branched-chain sugars

1983 ◽  
Vol 61 (9) ◽  
pp. 2112-2120 ◽  
Author(s):  
Jean-Richard Neeser ◽  
Jean M. J. Tronchet ◽  
Etienne J. Charollais
Keyword(s):  
Structural Analysis ◽  
Chemical Shift ◽  
Phosphine Oxide ◽  
Phosphorus Atom ◽  
Phosphine Oxides ◽  
Coupling Constant ◽  
Nmr Study ◽  
Branched Chain ◽  
Derivatives Of

A complete nmr study (1H, 13C, 31P) of twelve 3-C-phosphonates, -phosphinates, and -phosphine oxide derivatives of 3-C-branched-chain pento- and hexo-furanoses is reported. For all compounds the configuration at C3 is determined and, for oxaphospholanes 9 to 12, the configuration at the asymmetric phosphorus atom. The 3T2 conformation of the furanose ring of acyclic derivatives 1 to 8 and the conformationally rigid cis-fused oxaphospholane-furanose bicyclic systems of 9 to 12 have been used to study the 3JPCCH vs. θP.H and 3JPCCC vs. θP.C relationships which are specific to this series of compounds. The use of the ν P=O ir stretching frequency, δ 31P chemical shift, and 1JP.C coupling constant values in structural analysis of C-phosphorus-bearing sugars is also reported and discussed.

Carbamoyl and Thiocarbamoyl Derivatives of 3-Aminopropyl-dimethyl-phosphine Oxide

2004 ◽  
Vol 59 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Victoria Lachkova ◽  
Helmut Keck ◽  
Rosario Scopelliti ◽  
Wolfgang Kläui ◽  
Sabi Varbanov ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Phosphine Oxide ◽  
Elemental Analysis ◽  
Phosphine Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Derivatives Of

A series of fourteen new 3-[N-substituted carbamoyl (or thiocarbamoyl)]-aminopropyl-dimethyl-phosphine oxides have been synthesized and characterized. The compounds were prepared via reaction of the 3-aminopropyl-dimethyl-phosphine oxide with the corresponding isocyanates or isothiocyanates. The composition of the compounds was proved by elemental analysis and the structures were confirmed by IR, 1H, 31P, 31P{1H} NMR spectroscopy and by mass spectrometry. The structures of 3[(N-phenyl-thiocarbamoyl)amino]propyl-dimethyl-phosphine oxide (5), 3[(N-4- chlorophenyl-thiocarbamoyl)amino]propyl-dimethyl-phosphine oxide (6), and 3[(N-benzyl-thiocarbamoyl) amino]propyl-dimethyl-phosphine oxide (9) have been confirmed by X-ray diffraction.

scholarly journals On the Search of a Silver Bullet for the Preparation of Bioinspired Molecular Electrets with Propensity to Transfer Holes at High Potentials

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 429
Author(s):  
James Bennett Derr ◽  
Katarzyna Rybicka-Jasińska ◽  
Eli Misael Espinoza ◽  
Maryann Morales ◽  
Mimi Karen Billones ◽  
...  
Keyword(s):  
Free Acid ◽  
Building Blocks ◽  
Butyl Ether ◽  
One Pot ◽  
Nitrobenzoic Acid ◽  
Wide Range ◽  
High Potentials ◽  
Scalable Synthesis ◽  
High Yields ◽  
Derivatives Of

Biological structure-function relationships offer incomparable paradigms for charge-transfer (CT) science and its implementation in solar-energy engineering, organic electronics, and photonics. Electrets are systems with co-directionally oriented electric dopes with immense importance for CT science, and bioinspired molecular electrets are polyamides of anthranilic-acid derivatives with designs originating from natural biomolecular motifs. This publication focuses on the synthesis of molecular electrets with ether substituents. As important as ether electret residues are for transferring holes under relatively high potentials, the synthesis of their precursors presents formidable challenges. Each residue in the molecular electrets is introduced as its 2-nitrobenzoic acid (NBA) derivative. Hence, robust and scalable synthesis of ether derivatives of NBA is essential for making such hole-transfer molecular electrets. Purdie-Irvine alkylation, using silver oxide, produces with 90% yield the esters of the NBA building block for iso-butyl ether electrets. It warrants additional ester hydrolysis for obtaining the desired NBA precursor. Conversely, Williamson etherification selectively produces the same free-acid ether derivative in one-pot reaction, but a 40% yield. The high yields of Purdie-Irvine alkylation and the selectivity of the Williamson etherification provide important guidelines for synthesizing building blocks for bioinspired molecular electrets and a wide range of other complex ether conjugates.

The Coarse Scale Velocity

2017 ◽  
Author(s):  
Philip Isett
Keyword(s):  
Velocity Field ◽  
Building Blocks ◽  
Coarse Scale ◽  
Divergence Equation ◽  
Higher Derivatives ◽  
Order Of Magnitude ◽  
Derivatives Of

This chapter deals with the coarse scale velocity. It begins the proof of Lemma (10.1) by choosing a double mollification for the velocity field. Here ∈ᵥ is taken to be as large as possible so that higher derivatives of velement are less costly, and each vsubscript Element has frequency smaller than λ‎ so elementv⁻¹ must be smaller than λ‎ in order of magnitude. Each derivative of vsubscript Element up to order L costs a factor of Ξ‎. The chapter proceeds by describing the basic building blocks of the construction, the choice of elementv and the parametrix expansion for the divergence equation.

Directed, Palladium(II)-Catalyzed Enantioselective anti-Carboboration of Alkenyl Carbonyl Compounds

2019 ◽  
Author(s):  
Zhen Liu ◽  
Xiaohan Li ◽  
Tian Zeng ◽  
Keary Engle
Keyword(s):  
Carbonyl Compounds ◽  
Building Blocks ◽  
New Method ◽  
Carbon Based

A substrate-directed enantioselective <i>anti</i>-carboboration reaction of alkenes has been developed, wherein a carbon based nucleophile and a boron moiety are installed across the C=C bond through a 5- or 6-membered palladacycle intermediate. The reaction is promoted by a palladium(II) catalyst and a mondentate oxzazoline ligand. A range of enantioenriched secondary alkylboronate products were obtained with moderate to high enantioselectivity that could be further upgraded by recrystallization. This work represents a new method to synthesize versatile and valuable alkylboronate building blocks. Building on an earlier mechanistic proposal by Peng, He, and Chen, a revised model is proposed to account for the stereoconvergent nature of this transformation.

Synthesis of Nitrile-Bearing Quaternary Centers via an Equilibrium-Driven Transnitrilation and Anion-Relay Strategy

2019 ◽  
Author(s):  
Sebastien Alazet ◽  
Michael West ◽  
Purvish Patel ◽  
Sophie Rousseaux
Keyword(s):  
Building Blocks ◽  
One Pot ◽  
Quaternary Centers ◽  
Synthetic Intermediates

The efficient preparation of nitrile-containing building blocks is of interest due to their utility as synthetic intermediates and their prevalence in pharmaceuticals. As a result, significant efforts have been made to develop methods to access these motifs which rely on safer and non-toxic sources of CN. Herein, we report that 2-methyl-2-phenylpropanenitrile is an efficient, non-toxic, electrophilic CN source for the synthesis of nitrile-bearing quaternary centers via a thermodynamic transnitrilation and anion-relay strategy. This one-pot process leads to nitrile products resulting from the gem-difunctionalization of alkyl lithium reagents.<br>

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