Kurzmitteilung/Short Communication Darstellung und Eigenschaften von und Reaktionen mit metallhaltigen Heterocyclen, LXXV Synthese eines Diphosphamolybdacyclopentens durch Alkin‐Insertion in die P—P‐Bindung eines Diphosphamolybdacyclopropans

Metal‐Containing Heterocycles: Preparation, Properties, Reactions, LXXV 1) . — Synthesis of a Diphosphamolybdacyclopentene by Alkyne Insertion into the P ‐ P Bond of a Diphosphamolybdacyclopropane Insertion of the alkyne RCCR (R = CO 2 Me) into the P ‐ P bond of the diphosphamolybdacyclopropane ( 5 ‐C 5 H 5 )‐(OC) 2 Mo‐PPh 2 ‐PAr ( 2 ) [Ar = 2,4,6‐( t Bu) 3 C 6 H 2 ] results in the formation of the thermally and kinetically stable diphosphamolybdacyclopentene (η 5 ‐C 5 H 5 )(OC) 2 Mo‐PPh 2 ‐RC = CR‐PAr ( 3 ), which is characterized on the basis of mass, IR, 31 P{ 1 H}‐, 1 H‐, and 13 C{ 1 H}‐NMR spectra.