Insertion chemistry of iron(II) boryl complexes.
Dalton Trans
; 51(40): 15475-15483, 2022 Oct 18.
Article
em En
| MEDLINE
| ID: mdl-36156616
ABSTRACT
Iron(II) boryl complexes of the pyrrole-based pincer ligand, CyPNP (CyPNP = anion of 2,5-bis(dicyclohexylphophinomethyl)pyrrole) have been synthesized and their insertion reactivity interrogated. Compounds of the type [Fe(BE)(CyPNP)] (E = pinacholato or catecholato) can be generated by treatment of the precursors, [Fe(OPh)(py)(CyPNP)] or [FeMe(CyPNP)], with B2E2. The boryl complexes are meta stable, but permit additional reactivity with several unsaturated substrates. Reaction with alkynes, RCîCR', leads to rapid insertion into the Fe-B bond to generate stable vinyl boronate complexes of the type [Fe(C{R}C{R'}BE)(CyPNP)] (R, R' = H, Me, Ph, -CîCPh). Each of the compounds is five-coordinate in the solid state by virtue of coordination of one of the oxygen atoms of the boronate ester. Similar reaction with nitriles, RCîN (R = Ph, Me), results in facile de-cyanation to produce the correpsonding hydrocarbon complexes, [FeR(CyPNP)]. In the case of the bulky nitrile 1-AdCN, the insertion intermediate, [Fe(C{Ad}NBpin)(CyPNP)], has been isolated and structurally characterized. Treatment of the boryl complexes with styrene derivatives results in initial insertion to give an alkylboronate complex followed by either ß-H elimination or protonation to give the products of C-H borylation and hydroboration, respectively.
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Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos