In:
Chemistry – A European Journal, Wiley, Vol. 9, No. 11 ( 2003-06-06), p. 2516-2530
Abstract:
The ethene derivatives [(η 5 ‐C 5 R 5 )RuX(C 2 H 4 )(PPh 3 )] with R=H and Me, which have been prepared from the η 3 ‐allylic compounds [(η 5 ‐C 5 R 5 )Ru(η 3 ‐2‐MeC 3 H 4 )(PPh 3 )] ( 1, 2 ) and acids HX under an ethene atmosphere, are excellent starting materials for the synthesis of a series of new halfsandwich‐type ruthenium( II ) complexes. The olefinic ligand is replaced not only by CO and pyridine, but also by internal and terminal alkynes to give (for X=Cl) alkyne, vinylidene, and allene compounds of the general composition [(η 5 ‐C 5 R 5 )RuCl(L)(PPh 3 )] with L=C 2 (CO 2 Me) 2 , Me 3 SiC 2 CO 2 Et, CCHCO 2 R, and C 3 H 4 . The allenylidene complex [(η 5 ‐C 5 H 5 )RuCl(CCCPh 2 )(PPh 3 )] is directly accessible from 1 (R=H) in two steps with the propargylic alcohol HCCC(OH)Ph 2 as the precursor. The reactions of the ethene derivatives [(η 5 ‐C 5 H 5 )RuX(C 2 H 4 )(PPh 3 )] (X=Cl, CF 3 CO 2 ) with diazo compounds RR′CN 2 yield the corresponding carbene complexes [(η 5 ‐C 5 R 5 )RuX(CRR′)(PPh 3 )], while with ethyl diazoacetate (for X=Cl) the diethyl maleate compound [(η 5 ‐C 5 H 5 )RuCl{η 2 ‐ Z ‐C 2 H 2 (CO 2 Et) 2 }(PPh 3 )] is obtained. Halfsandwich‐type ruthenium( II ) complexes [(η 5 ‐C 5 R 5 )RuCl(CHR′)(PPh 3 )] with secondary carbenes as ligands, as well as cationic species [(η 5 ‐C 5 H 5 )Ru(CPh 2 )(L)(PPh 3 )]X with L=CO and CN t Bu and X=AlCl 4 and PF 6 , have also been prepared. The neutral compounds [(η 5 ‐C 5 H 5 )RuCl(CRR′)(PPh 3 )] react with phenyllithium, methyllithium, and the vinyl Grignard reagent CH 2 CHMgBr by displacement of the chloride and subsequent CC coupling to generate halfsandwich‐type ruthenium( II ) complexes with η 3 ‐benzyl, η 3 ‐allyl, and substituted olefins as ligands. Protolytic cleavage of the metal–allylic bond in [(η 5 ‐C 5 H 5 )Ru(η 3 ‐CH 2 CHCR 2 )(PPh 3 )] with acetic acid affords the corresponding olefins R 2 CCHCH 3 . The by‐product of this process is the acetato derivative [(η 5 ‐C 5 H 5 )Ru( κ 2 ‐O 2 CCH 3 )(PPh 3 )], which can be reconverted to the carbene complexes [(η 5 ‐C 5 H 5 )RuCl(CR 2 )(PPh 3 )] in a one‐pot reaction with R 2 CN 2 and Et 3 NHCl.
Type of Medium:
Online Resource
ISSN:
0947-6539
,
1521-3765
DOI:
10.1002/chem.200304740
Language:
English
Publisher:
Wiley
Publication Date:
2003
detail.hit.zdb_id:
1478547-X
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