Directed <i>Ortho</i>-Lithiation of Aminophosphazenes: An Efficient Route to the Stereoselective Synthesis of <i>P</i>‑Chiral Compounds

<i>Ortho</i>-directed lithiation of <i>P</i>,<i>P</i>-diphenylaminophosphazenes followed by electrophilic quench is described as an efficient process for synthesizing <i>P</i>-chiral <i>ortho</i>-functionalized derivatives in high yields and diastereoselectivities. The method allows the tunable preparation of structurally diverse enantiopure <i>P</i>-chiral compounds including phosphinic and phosphinothioic amides, phosphinic esters, phosphine oxides, and <i>o</i>-aminophosphines

Phyllanthus emblica

The experimentally observed stereomutation of spiro-1,2-oxaphosphetanes is shown by DFT calculations to proceed through successive M_B2 or M_B4 and M_B3 mechanisms involving two, four, and three Berry pseudorotations at phosphorus, respectively. Oxaphosphetane decomposition takes place in a single step via a polar transition state. The calculated activation parameters for this reaction are in good agreement with those determined experimentally

Cycloaurated Phosphinothioic Amide Complex as a Precursor of Gold(I) Nanoparticles: Efficient Catalysts for A³ Synthesis of Propargylamines under Solvent-Free Conditions

A C,S-cycloaurated complex based on an ortho-substituted phosphinothioic amide framework has been synthesized in high yield through tin­(IV)–Au­(III) transmetalation from the corresponding chlorodimethylstannyl derivative. The latter was prepared in a two-step process involving directed ortho lithiation/quenching with Me₃SnCl followed by Me/Cl exchange. The tin­(IV) and gold­(III) complexes have been characterized in solution and in the solid state. In both complexes, the phosphinothioic amide moiety acts as a C–C–P–S pincer ligand with formation of five-membered-ring metalacycles. The use of the gold­(III) complex in the amine–aldehyde–alkyne (A³) three-component coupling synthesis of propargylamines showed that the compound is transformed into the Sonogashira-type <i>o</i>-alkynylphosphinothioic amide with generation of Au­(I) nanoparticles with an average size of around 7 nm. These nanoparticles proved to be excellent catalysts in A³ coupling processes, providing propargylamines in high yields under solvent-free conditions with loadings as low as 0.1 mol % and without the use of additives