Darstellung und Eigenschaften von und Reaktionen mit metallhaltigen Heterocyclen, XLIV. Einfluß der Ligandensphäre am Mangan auf die Stabilität der fünfgliedrigen Heterocyclen

Preparation and Properties of, and Reactions with, Metal‐Containing Heterocycles, XLIV. Influence of the Ligand Sphere at Manganese on the Stability of the Five‐membered Heterocycles The five‐membered heterocycle ( 3b ) is obtained by reductive cyclization of the bifunctionalized complex (OC) 3 (Ph 3 P)(Br)MnPPh 2 OCH 2 CH 2 Cl ( 2 b ) with sodium amalgam at −5°C in ether. A meridional arrangement of the CO groups and the trans ‐position of the two P atoms in 2b, 3b can be deduced from the IR and 31 P{ 1 H} NMR spectra. Compared to 3a the phosphane ligand causes a destabilization of 3b .