om6b00743_si_002.pdf (1.73 MB)
Reactivity Studies of [(thf)2Mg{μ-C(CH3)2C2H4C(CH3)2}]2: Scrambling Reactions and Diverse Reactions with Dichlorophenylphosphane
journal contribution
posted on 2016-11-04, 13:28 authored by Reinald Fischer, Helmar Görls, Matthias WesterhausenIn
THF solution [{(thf)2Mg{μ-C(CH3)2C2H4(CH3)2C}}2] (1) exchanges the alkanediide ligand with [{(thf)2Mg{μ-CH2)5}}2] in an
equilibrium leading to the formation of [{(thf)2Mg}2{μ-C(CH3)2C2H4C(CH3)2}{μ-(CH2)5}] (2). Depending on the crystallization temperature,
homoleptic 1 or heteroleptic 2 crystallizes
from THF solutions, verifying a temperature-dependent Schlenk equilibrium.
Irradiation of a solution of 1 in [D8]THF
with UV light yields magnesium hydride and alkene via a β-hydride
elimination reaction. In a metathetical approach dichlorophenylphosphane reacts with 1 in THF to give the intermediate “PhP(Cl){C(CH3)2C2H4(CH3)2CMgCl” (3-MgCl), which forms three subsequent
products. In order to ease handling and characterization of these
compounds, hydrolysis and oxidation with sulfur has been performed.
This product mixture was separated by column chromatography, yielding
the chlorophosphane sulfide [Ph(S)P(Cl){C(CH3)2C2H4(CH3)2CH)}] (3-S), the cyclic phosphane sulfide [Ph(S)P{C(CH3)2C2H4(CH3)2C)}] (4-S), and the cyclic 1,1-diphosphane disulfide
[{(Ph(S)P}2{μ-C(CH3)2C2H4(CH3)2C}] (6-S2). Furthermore, traces of the acyclic 1,1-diphosphane
disulfides [{PhP(S)(C(CH3)2C2H4CH(CH3)2)}{PhP(S)(C(CH3)2C2H4C(CH3)(CH2)}] (8-S2) and meso-[{Ph(S)P(C(CH3)2C2H4(CH3)2CH)}2] (7-S2) have also
been isolated. Compounds 6–8 represent
the phosphorus-containing products of indirect Grignard reductions.
