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Formal coupling of two alkylidyne ligands on a metal center
Author(s) -
Mayr Andreas,
Bastos Cecilia M.,
Daubenspeck Nancy,
McDermott Gregory A.
Publication year - 1992
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.19921250712
Subject(s) - chemistry , alkyne , methyllithium , carbyne , stereochemistry , carbene , medicinal chemistry , metal , catalysis , organic chemistry
Abstract Reaction of the alkylidyne complexes [W(CR)Br(CO) 3 L] [ 2b (L = CO; R = C 6 H 4 ‐OMe‐4), 2c (L = CO, R = C 6 H 4 ‐NMe 2 ‐4), 3a (L = PPh 3 ; R = Ph), and 3c (L = PPh 3 ; R = C 6 H 4 ‐NMe 2 ‐4)] with methyllithium in THF at ‐78°C affords the alkylidyne acyl tungsten complexes Li[W(CR)(COMe)Br(CO) 3 L] [ 4b (L = CO; R = C 6 H 4 ‐OMe‐4), 4c (L = CO, R = C 6 H 4 ‐NMe 2 ‐4), 5a (L = PPh 3 ; R = Ph), and 5c (L = PPh 3 ; R = C 6 H 4 ‐NMe 2 ‐4)]. Reaction of complexes 4 and 5 with C 2 O 2 Br 2 at ‐78°C‐0°C in CH 2 Cl 2 followed by addition of PPh 3 gives the alkyne complexes [WBr 2 (CO)(CH 3 C = CR)(PPh 3 ) 2 ] ( 6 ). The formation of the alkyne ligands in complexes 6 may be considered as the result of formal coupling of two alkylidyne ligands.