In:
New Journal of Chemistry, Royal Society of Chemistry (RSC), Vol. 46, No. 16 ( 2022), p. 7512-7521
Abstract:
Four aryl cobalt and iron complexes, [(F 4 C 5 N)Co(Cl)(PMe 3 ) 3 ] (1), [(F 4 C 5 N)Fe(PMe 3 ) 4 ] (2), [(F 5 C 6 )Co(Cl)(PMe 3 ) 3 ] (3) and [(F 5 C 6 )Fe(Cl)(PMe 3 ) 3 ] (4), were synthesized from the reactions of 3-chloro-2,4,5,6-tetrafluoro-pyridine and chloropentafluorobenzene with Co(PMe 3 ) 4 and Fe(PMe 3 ) 4 , respectively. Under similar reaction conditions, the reaction of 3-chloropyridine with Co(PMe 3 ) 4 afforded CoCl(PMe 3 ) 3 as a single-electron oxidative addition product. Complexes 1–4 were used as catalysts for alkene hydrosilylation. It was found that cobalt( ii ) complex 1 is the best catalyst for hydrosilylation of alkenes with Markovnikov selectivity for aryl alkenes and anti-Markovnikov selectivity for aliphatic alkenes. Using HCOONa or NaBHEt 3 as an additive, the catalytic reaction could be promoted. In particular, with NaBHEt 3 , the catalytic reaction could be carried out under mild conditions (40 °C) with high conversion and good selectivity for most substrates selected. Using 1 mol% 1 as a catalyst, the gram-scale reaction of styrene with Ph 2 SiH 2 gave rise to the product in 93% yield with excellent selectivity (b/l = 97 : 3). Complexes 1 and 3 reacted with phenylethynyl lithium to afford alkynyl cobalt complexes 6 and 7, respectively. Complex 2 was stable in CH 3 I. Complexes 1, 2, 4, 6 and 7 are new complexes and the molecular structures of them were determined by single crystal X-ray diffraction analysis.
Type of Medium:
Online Resource
ISSN:
1144-0546
,
1369-9261
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2022
detail.hit.zdb_id:
1472933-7
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