Metal Nitrosyl Reactivity: Acetonitrile-Promoted Insertion of an Alkylidene into a Nitrosyl Ligand with Fission of the NO Bond

✍ Scribed by C. M. Frech; O. Blacque; H. W. Schmalle; H. Berke

• Book ID: 102793549
• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 932 KB
• Volume: 12
• Category: Article
• ISSN: 0947-6539
• DOI: 10.1002/chem.200600286

✦ Synopsis

Abstract

Treatment of the complexes [Re(NO)~2~(PR~3~)~2~][BAr^F^~4~] (R = Cy, 1 a; R = i__Pr, 1 b) with phenyldiazomethane gave the cationic benzylidene species [Re{CH(C~6~H~5~)}(NO)~2~(PR~3~)~2~][BAr^F^~4~] (2 a and 2 b) in good yields. Upon reaction of 2 a and 2 b with acetonitrile, the consecutive formation of [Re(NCCH~3~)(NCPh)(NO)(OC(CH~3~)NH)(PR~3~)][BAr^F^~4~] (3 a and 3 b) and [Re(NCCH~3~)(OC{CH~3~}NH{C~6~H~5~})(NO)(PR~3~)~2~][BAr^F^~4~] (4 a and 4 b) was observed. The proposed reaction sequence involves the coupling of coordinated NO, carbene and acetonitrile molecules to yield the (1__Z)‐N‐[imino(phenyl)methyl]ethanimidate ligand. The coupling of the nitrosyl and the benzylidene is anticipated to occur first, forming an oximate species. The subsequent acetonitrile addition can be envisaged as a heteroene reaction of the oximate and the acetonitrile ligand yielding 3 a and 3 b, which in turn can cyclise and undergo a prototropic shift initiated by an internal attack of the ethaneimidate ligand on the benzonitrile moiety to afford 4 a and 4 b.