New synthesis of S(Se)-alkyl phosphorothio(seleno)lates from the corresponding phosphoroanilidates. Stereospecific cleavage of the phosphorus-nitrogen bond in chiral phosphoroanilidates

Exploring reactivity of a bis-sulfonium zirconocene-ate dimer: Synthesis of various zwitterionic phosphonium anionic zirconocene complexes

“…The Cp 2 Zr fragment demonstrates typical features for bent metallocenes (Cp-Zr = 2.246(4), 2.223(4) Å and Cp(1)-Zr-Cp(2) = 127.1°). The molecular structure of 4 shows the structural characteristics of anionic five-coordinate Cp 2 Zr(IV) complexes previously reported [6][7][8][9][10]: (i) the large S(1)-Zr-S(2) angle value of 144.4(1)°due to the necessity of achieving a good orbital overlap for bonding the fifth ligand as well as the resolving of the steric requirements of the ligands [4][5][6][7][8][9][10] and consequently (ii) the three long Zr-X (X = C, S) bond lengths in the equatorial plane that bisects the Cp groups (Zr-C(13) 2.392(4), Zr-S(1) 2.6336 (12), Zr-S(2) 2.7670(13) Å ). The two S-C(14) bond lengths coming from the CS 2 reagent (S(2)-C(14) 1.687 (5) and S(3)-C(14) 1.659(5) Å ) are intermediate between single-bond and double-bond distances revealing a delocalized p-bonding scheme for this fragment (Chart 1) [9].…”

Synthesis and characterization of the new ambidentate O-cholesteryl-O-phenyl phosphorothioate ligand and its organoarsenic derivatives of phenoxarsin-10-yl and phenothiarsin-10-yl phosphorothioate

“…The sodium salt of O-cholesteryl-O-phenyl phosphorothioate (2: Na[S(O)PRRЈ]) was obtained from (1) [17] according to known procedures for this type of reaction [20].…”

The Stereochemistry of P-N Bond Cleavage in the Staudinger -Wittig-type Reaction of 2-Anilido-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine-2-thiones

“…In the course of our studies on the application of phosphoranilidates in the synthesis of nucleotides and nucleoside phosphorothioates [2,3] we have found that dialkyl(aryl)phosphoranilidates can be conveniently converted into corresponding phosphates and phosphorothioates upon treatment with sodium hydride followed by carbon dioxide or carbon disulphide, respectively. We were also able to prove that in the case of chiral acyclic molecules as well as in 4-methyl-l,3,2-dioxaphosphorinane derivatives this process is fully stereospecific and proceeds with retention of configuration at phosphorus [4]. Taking into account that stereochemistry of several reactions at phosphorus depends on the nature of substituents surrounding the reaction centre and on the reaction conditions [5] we decided to investigate the stereoselectivity of the conversion in question in a case, when the phosphorus atom is incorporated into a five-membered ring.…”