058ChemInform Abstract In solution the dimeric thiophosphinito-Mn complexes (I) are in equilibrium with the appropriate monomeric species (II), which are kinetically stabilized in the case of (IIc) and (IId). In THF the complexes (II) react with activated alkynes such as (IV) to give (III) or (V), dependent on the conditions used. The course of reaction of (IIc) and (IId) with alkynes is strongly dependent on the polarity of the solvent. In THF also the five-membered metallacycles (VI) are formed, whereas in hexane seven-membered compounds (VIII) are obtained. (VIb) crystallizes in P21/n with Z=4. At elevated temp. (VIII) eliminates CO with formation of bicyclic compounds such as (IX). (IX), (XI) (which was prepared previously similarly to (V) via type (III) with two different alkynes) and (Vd) are starting compounds for easy access to different substituted thiophenes such as (X) and (XII), furanes such as (XIII), and the phosphole complex (XIV).

254ChemInform Abstract The title compounds (III) and (V) are obtained from BrMn(CO)5 (I) and sec. phosphine sulfides (II) and (IV) in dependence on the phosphine substituent. The Mn-S bond in the monomer (IIIa) is easily and reversibly cleaved under CO pressure resulting in the formation of the pentacarbonyl (VII).

The η2(P‐S)‐Mn complex (III) obtained as shown reacts with the acetylenedicarboxylates (IV) in hexane to give the P‐isomeric manganacycloheptadiene compounds (V) as the main‐products.