om970031b_si_001.pdf (501.04 kB)
Manganese Thiophene Tricarbonyl Complexes: Nucleophilic Addition to Sulfur and Synthesis of Thiophenium Salts
journal contribution
posted on 1997-04-15, 00:00 authored by Su Seong Lee, Tae-Young Lee, Dae Seung Choi, Jun Sik Lee, Young Keun Chung, Soon W. Lee, Myoung Soo LahNew thiophene manganese derivatives,
[(2-R1-C4H3S)Mn(CO)3]+
1(sil) (R1 =
Si(OCH2CH2)3N) and 1(Mn) (R1 =
(C6H6)Mn(CO)3), have been
synthesized and their reaction with
nucleophiles studied. Except for the Grignard reagent,
nucleophiles (Nu- = H-,
-CN,
-P(O)(OR)2 (R = Me, Ph)) usually
attack the C5 position. Grignard reagents attack the
sulfur atom to yield manganese S-R-thiophene carbonyls
3. To compare the reactivities of
1(sil) and 1(Mn) with that of
(thiophene)Mn(CO)3+ with respect to
Grignard reagent addition,
the known compounds
[(thiophene)Mn(CO)3]+ (thiophene
= thiophene, 2-methylthiophene,
2,5-dimethylthiophene) have been synthesized and their reaction with
Grignard reagents
studied. In all cases, S-R-thiophene manganese
carbonyls 3 were obtained as a sole product.
Refluxing 3 (R = Ph, p-tolyl, 2-thienyl)
with Me3NO in benzene yielded diaryl
sulfide.
Treatment of 3 with NOBF4 in
CH2Cl2 led to S-R-thiophenium−manganese
dicarbonyl
nitrosyl cations 4. Photolysis of 4 in
acetone gave rise to S-R-thiophenium 5 in high
yields.
The molecular structures of
[{2-exo-P(O)(OMe)2-η4-C4H3S}Mn(CO)3]
(2(sil,P(O)(OMe)2)),
[S-Ph-η4-2-{(η5-C6H6)Mn(CO)3}SC4H3]Mn(CO)3
(3(Mn,Ph)), and
[p-CH3C6H5-S-2-CH3C4H3]
(5(Me,p-tolyl)) have been determined by X-ray
studies.