Synthetic and reaction chemistry of heteroatom stabilized boryl and cationic borylene complexes.
The synthesis, spectroscopic and structural characterization of the aryloxy and amino functionalized chloroboryl complexes (eta(5)-C(5)R(5))Fe(CO)(2)B(OMes)Cl (R = H, 2a ; R = Me, 3a) and (eta(5)-C(5)H(5))Fe(CO)(2)B(N(i)Pr(2))Cl (7a) are reported. Compound 2ais shown to be a versatile substrate for further boron-centred substitution chemistry leading to the asymmetric boryl complexes (eta(5)-C(5)H(5))Fe(CO)(2)B(OMes)ER(n) [ER(n) = OC(6)H(4)(t)Bu-4, 2c; ER(n) = SPh, 2d] with retention of the metal-boron bond. The reactivities of 2a, 3a and 7a towards the halide abstraction agent Na[BAr(f)(4)] have also been examined, in order to investigate the potential for the generation of cationic heteroatom-stabilized terminal borylene complexes. The application of this methodology to the mesityloxy derivatives and gives rise to B-F containing products, presumably via fluoride abstraction from the [BAr(f)(4)](-) counter-ion. By contrast, amino-functionalized complex 7a is more amenable to this approach, and the thermally robust terminal aminoborylene complex [(eta(5)-C(5)H(5))Fe(CO)(2)B(N(i)Pr(2))][BAr(f)(4)] (9) can be isolated in ca. 50% yield. The reactivity of 9towards a range of nucleophilic and/or unsaturated reagents has been examined, with examples of addition, protonolysis and metathesis chemistries having been established.
Kays Née Coombs
Deborah L
DL
Centre for Fundamental and Applied Main Group Chemistry, School of Chemistry, Cardiff University, UK.
Rossin
Andrea
A
Day
Joanne K
JK
Ooi
Li-Ling
LL
Aldridge
Simon
S