Synthesis and structures of [S(H)P(μ-NR)]₂, potential building blocks for inorganic phosphorus–sulfur macrocycles

Abstract

The reactions of the chloro-phosph(iii)azane dimers [ClP(μ-NR)]2 with LiSH give the dimers [S[double bond, length as m-dash](H)P(μ-NR)]2 (), which are potential new building blocks for inorganic macrocycles of the type [{P(μ-NR)}2(μ-S)]n. NMR spectroscopic studies and DFT calculations show that the preference for the cis or trans isomers of is largely influenced by the steric demands of the R-group, with cis isomers being preferred for bulky substituents. This is an important factor in regard to applications in macrocycle synthesis since the cis arrangement is pre-organized for cyclisation.

A Modular Approach to Inorganic Phosphazane Macrocycles

“…Here we show that [S=(H)P(μ‐NR)] 2 ( 1 ) (the sulfur analogues of C , Scheme ) can be employed in a simple set of versatile, one‐pot reactions to obtain both hexameric P III /P V and all‐P V macrocyles related to D , and trimeric macrocycles related to E (Scheme ) . Significantly, our new method improves the yields of this type of macrocycle dramatically from approximately 10–45 % using the previous Wurtz‐type approach to over 80 % for the related macrocyles.…”

A Modular Approach to Inorganic Phosphazane Macrocycles

“…[36,37] Significantly, our new method improves the yields of this type of macrocycle dramatically from approximately 10-45 % using the previous Wurtz-type approach [29,30] to over 80 % for the related macrocyles. This approach also allows a large range of achiral and chiral R-groups to be introduced into these arrangements (apart from t Bu alone, as in all previous examples), as well as all P V derivatives (which are air stable).…”

Designing the Macrocyclic Dimension in Main Group Chemistry

“…A range of nucleophilic precursors [(S=)(H)P(μ‐NR)] 2 (11H 2 ) (R= t Bu, Dipp, Mes, CHPh 2 ) can be readily accessed by reactions of the corresponding dichloride dimers [ClP(μ‐NR)] 2 with LiSH at −78 °C in thf (Scheme ) . The preference for the cis ‐ or trans ‐isomer is dependent on the steric bulk of the R‐group ( t Bu>Dipp>Mes>CHPh 2 ), with the cis ‐isomer being preferred for more sterically demanding groups under normal conditions.…”