Methylidynetrisphosphonates: Promising C1 building block for the design of phosphate mimetics

In(III)-Catalyzed 1,2-Hydrophosphorylation of 3-Alkynyl-3-hydroxyisoindolinones to 3,3-Disubstituted Isoindolinones Featuring Both Phosphoryl and Alkynyl Groups at the C3-Position

We report a highly regioselective 1,2-addition of P(O)-H compounds to the in situ generated β,γ-alkynyl-α-ketimine derived from 3-alkynyl-3-hydroxyisoindolinones, which provided a general protocol for the preparation of 3,3-disubstituted isoindolinones featuring both phosphoryl and alkynyl groups at a quaternary carbon center. The use of only 2-5 mol % of an inexpensive catalyst (In(ClO4)3·8H2O or Bi(OTf)3) allowed the smooth output of the desired products under mild conditions (25 °C, 0.5-24 h) with a broad substrate scope (35 examples) in up to >99% yield. The obtained products could be further elaborated based on the alkyne moiety. The initial asymmetric trial indicated that the use of BINOL-derived CPA could enable an enantioselective induction in up to a 46% yield with 77% ee.

Theoretical study of the chemical reactivity of a class of trivalent phosphorus derivatives towards polyhaloalkanes: DFT study

In the current work, the chemical reactivity of some trivalent phosphorus derivatives R₂PR^' towards polyhaloalkanes CCl₃POR ' '₂ was studied by the quantum method DFT/B3LYP/6-311G(d,p). The introduction of substituents for the trivalent phosphorus derivative and polyhaloalkane allowed us to have more information on these reactions. On the one hand, the calculation of reactivity indices derived from the DFT/B3LYP/6-311G(d,p) method and the gap_{LUMO - HOMO} show that trivalent organophosphorus derivatives behave as nucleophiles, while polyhaloalkanes act as electrophiles. On the other hand, the calculation of the activation barrier and the determination of the free enthalpy variation prove that the kinetic and thermodynamic products of these reactions result from the nucleophilic attack of the phosphorus atom on the chlorine halogen. All these theoretical predictions are in very good agreement with the experimental results.

Catalytic Direct Regioselective Synthesis of Phosphonylated Tetrazoles from Aryl Diazonium Salts and Seyferth-Gilbert Reagent

Here we report a Ag-catalyzed [3 + 2] cycloaddition reaction between aryl diazonium salts and Seyferth-Gilbert reagent in a regioselective manner. This operationally simple transformation proceeds in an atom-economical way under mild reaction conditions, providing facile access to a broad set of phosphonylated tetrazoles. The synthetic utility of this method is further showcased by a straightforward procedure from upstream aromatic amines, denitrogenation transformations, and preparation of a phosphonylated drug scaffold.

Pd(0)-Catalyzed Cyclizative Phosphorylation of (Z)-1-Iodo-1,6-diene: Synthesis of Alkylphosphonate and Alkylthionophosphonate

A palladium-catalyzed cyclizative phosphorylation reaction of (Z)-1-iodo-1,6-diene with diethyl H-phosphonate is developed, which provides facile access to unsaturated six-membered heterocycles bearing an alkylphosphonate group. The key step of this process is the efficient capture of the involved alkyl-Pd(II) species by H-phosphonate with the help of CsF, followed by reductive elimination of alkyl-Pd(II)-P(O)(OEt)₂. Moreover, this reaction is successfully extended to H-thionophosphonate.

Palladium-Catalyzed Benzylic Phosphorylation of Diarylmethyl Carbonates

A palladium-catalyzed benzylic substitution of tert-butyl diarylmethyl carbonates with a pinacol-derived H-phosphonate proceeds to deliver the corresponding benzylic phosphorylated products in good yields. Moreover, the asymmetric synthesis is possible via a Pd/( R_p, R'_p)-( S)-Mandyphos-catalyzed kinetic resolution-DYKAT (dynamic kinetic asymmetric transformation) sequence, and optically active α-chiral diarylmethylphosphonates are obtained with synthetically useful yields and enantiomeric ratios (up to 50% and 92:8 er).

A highly efficient nucleophilic substitution reaction between R2P(O)H and triarylmethanols to synthesize phosphorus-substituted triarylmethanes

A highly efficient nucleophilic substitution reaction between R₂P(O)H and triarylmethanols was reported, which provides phosphorus-substituted triarylmethanes in rich diversity with 40–96% yields.

First DMAP-mediated direct conversion of Morita-Baylis-Hillman alcohols into γ-ketoallylphosphonates: Synthesis of γ-aminoallylphosphonates

An efficient synthesis of a series of γ-ketoallylphosphonates through a direct conversion of both primary and secondary Morita–Baylis–Hillman (MBH) alcohols by trialkyl phosphites with or without DMAP, used as additive, and under solvent-free conditions, is described herein for the first time. Subsequently, a highly regioselective Luche reduction of the primary phosphonate 2a (R = H) gave the corresponding γ-hydroxyallylphosphonate 5 that further reacted with tosylamines in the presence of diiodine (15 mol %) as a catalyst, affording the corresponding S_N2-type products 6a–d in 63 to 70% isolated yields. Alternatively, the alcohol 5 produced the corresponding acetate 7 which, mediated by Ce(III), was successfully converted into the corresponding γ-aminoallylphosphonates 8a–d.

Synthetic Procedures Leading towards Aminobisphosphonates

Growing interest in the biological activity of aminobisphosphonates has stimulated the development of methods for their synthesis. Although several general procedures were previously elaborated to reach this goal, aminobisphosphonate chemistry is still developing quite substantially. Thus, innovative modifications of the existing commonly used reactions, as well as development of new procedures, are presented in this review, concentrating on recent achievements. Additionally, selected examples of aminobisphosphonate derivatization illustrate their usefulness for obtaining new diagnostic and therapeutic agents.

Exceptional effect of nitro substituent on the phosphonation of imines: the first report on phosphonation of imines to α-iminophosphonates and α-(N-phosphorylamino)phosphonates

A novel chemoselective method for the simple phosphonation of imines withH-phosphonate diethyl ester and study of the electronic and orientation effects of the substituents on phosphorylation reaction.

Palladium-catalyzed α-arylation of benzylic phosphonates

A new synthetic route to access diarylmethyl phosphonates is presented. The transformation enables the introduction of aromatic groups on benzylic phosphonates via a deprotonative cross-coupling process (DCCP). The Pd(OAc)2/CataCXium A-based catalyst afforded a reaction between benzyl diisopropyl phosphonate derivatives and aryl bromides in good to excellent isolated yields (64-92%).