Synthesis, crystal structure and theoretical studies of the first endo∶endo-2,4-diphosphabicyclo[1.1.0]butane Electronic supplementary information (ESI) available: calculation data and atomic coordinates for compounds 4–6. See http://www.rsc.org/suppdata/cc/b1/b100993l/

Abstract

The reaction of PbCl₂ with Z-[CyPC(Bu^t)MgCl(OEt₂)] (Cy = cyclohexyl) affords the first example of an endo∶endo-2,4-diphosphabicyclo[1.1.0]butane, Cy₂P₂C₂Bu^t₂, which displays unusual spectroscopic and geometric properties, the origins of which have been explored by theoretical calculations.