New Intermediates in the Cyclocotrimerization of Thioxophosphorus(V) Cations with Alkynes

Abstract

A thiaphosphametallacyclopropane and a thiaphosphametallacycloheptadiene are important intermediates for understanding the mechanism of the cyclotrimerization of thioxophosphorus(V) cations and alkynes. These species are accessible by use of a bulky substituent R at the phosphorus atom. Compounds 2 are formed from the metallacyclopropane 1 and dimethyl or diethyl acetylenedicarboxylate in hexane. Upon heating in THF, they lose CO and are transformed into the known metallabicycloheptadienes 3. R1 = cyclohexyl; R2 = CO2Me, CO2Et.

An Organometallic Radical Route to Bis(phosphido)- and Hydrido−Phosphido-Bridged Metal−Metal-Bonded Complexes of Cyclopentadienylchromium via Desulfurization of Thiophosphinito Ligands

“…The structure of the molecule of 2a (Figure ) contains a CpCr moiety bonded to two CO ligands and a η 2 -thiophosphinito ligand. This side-on mode of bonding has been structurally established for only a few complexes . The P−S bond distances in 2a , b (see Table ), slightly shorter than those in the literature examples, are intermediate between those of the typical PS (range 1.926(1)−1.966(2) Å) and the P−S (2.122(1) Å) single bond in such ligands …”

Recent advances in organophosphorus–chalcogen and organophosphorus–pincer based macrocyclic compounds and their metal complexes

“…The preceding structural and theoretical investigations have revealed that the negative charge of the species containing [R 2 PvE] − anions (E = O, S, Se, NR, etc.) routinely lies predominantly on E. [126][127][128][129][130] In this regard, Wright and co-workers showed that the oligomerisation of P 2 N 2 units can be achieved by the reaction of the deprotonated P(H)vO group with a P-Cl bond which probably proceeds through a change of the nucleophile center from phosphorus to oxygen, as shown in Scheme 20. 121 The first example of the crown-like phosphazane based macrocycle [{P(μ-N t Bu)} 2 (μ-O)] 4 (50), containing oxo-bridges was synthesized by condensing P 2 N 2 rings possessing P(H)vO and P-Cl moieties.…”