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Mono‐ and Bicyclic Organometallic Ring Systems with Exocyclic CC and CS Bonds
Author(s) -
Werner Helmut,
Xiaolan Liu,
Peters Karl,
von Schnering Hans Georg
Publication year - 1997
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19971300710
Subject(s) - chemistry , protonation , bicyclic molecule , double bond , substituent , ring (chemistry) , alkyne , stereochemistry , delocalized electron , medicinal chemistry , metallacycle , ligand (biochemistry) , x ray crystallography , organic chemistry , physics , diffraction , optics , ion , biochemistry , receptor , catalysis
The cobaltaheterocycles [C 5 H 5 Co{κ 2 (C,S)‐C(=CH 2 )‐N(R)C(=S)S](PMe 2 Ph)] ( 5‐7 ), which contain both an exocyclic CC and CS bond, were prepared from the iminoacylcobalt compounds [C 5 H 5 Co(C(CH 3 )=NCH} (PMe 2 Ph)]I ( 2‐4 ) on treatment with either CS 2 /NaOCH 3 or K[S 2 CNMe 2 ], respectively. While protonation of 5 (R = CH 3 ) and 7 (R = CH 2 Ph) with HBF 4 occurs at the exocyclic CCH 2 bond to give cations containing a CoC(CH 3 )N(R)C(=S)S ring, the methylation of 5 and 7 with [OMe 3 ]BF 4 takes place at the exocyclic CS bond and generates five‐membered heterocycles heterocycles with an SCH 4 substituent. The reaction of 5‐7 with S 8 leads to the elimination of the phosphane ligand and affords the bicyclic dithiolenecobalt complexes 14 ‐ 16 in moderate to good yields. On treatment of 5 ‐ 7 with C 2 (CO 2 R′)2 (R′ = Me,Et), an insertion of the alkyne into the CCH 2 bond occurs and five‐membered ring systems 19 ‐ 22 with an unsaturated exocyclic =C(CO 2 R′)‐C(CO 2 R′)=CH 2 group are formed. As in the case of 5 and 7 , protonation and methylation reactions of 19 also take place at different sites leading to cations with either a delocalized CoCN or NCS unit.