Synthesis and Reactivity of Mn–CF3 Complexes

Abstract

The synthesis, characterization and reactivity of several bi- and tridentate, N-ligated manganese carbonyl trifluoromethyl complexes are presented. These complexes exhibit elongated Mn–CCF3 bonds (versus Mn(CF3)(CO)5), suggesting a lability that could be utilized for the transfer or insertion of the CF3 functional group into organic substrates. Unlike their Mn–X congeners (X = Cl, Br), these Mn–CF3 complexes exhibit a preference for hard donor ancillary ligands, thus enabling the synthesis of 4 N-ligated Mn–CF3 complexes including a mixed-donor tridentate complex using an NNS Schiff base ([2-(methylthio)-N-(1-(pyridin-2-yl)ethylidene)aniline]). Although we have not yet identified efficient CF3 transfer reactions, fluoride abstraction from the Mn–CF3 complexes using trimethylsilyl triflate affords the first stable Mn fluorocarbenes as evidenced by 19F NMR spectroscopy.

Synthesis, Characterization, and X-ray Crystallography, of the First Cyclohexadienyl Trifluoromethyl Metal Complex (η5-C6H7)Fe(CO)2CF3

“…In the analyzed structure and in line with what it has been reported before for structures of metal coordinated cyclohexadienyl organic rings [ 25 ], the six carbons are highly nonplanar, with one of them, the one and only saturated carbon being out of the plane that the remaining five carbon atoms form. Specifically, the methylene carbon lies ~0.63 Å above the unsaturated ring, and the Fe atom is 1.60 Å away from the plane of this ring, analogously to the corresponding values (~0.65 and 1.66 Å) reported by Shirin, et al for a Ru-coordinated cyclohexadienyl ring [ 25 ]. The dihedral angle between the plane of the five carbons and the second plane of the three carbons that contains the saturated carbon is 45°, which is slightly larger but analogous to the 40° recorded for the (2-methoxycyclohexadienyl)Fe(CO) 3 + species [ 26 ].…”

Syntheses and Characterization of the First Cycloheptatrienyl Transition-Metal Complexes with a M-CF3 Bond

“…Even though routes to LnMCH3 complexes are well-established, utilizing highly efficient, commercially available reagents, such as CH3Li and CH3MgBr, for the synthesis [16], analogous routes to of LnMCF3 derivatives are not straightforward as it is not similarly…”

“…Even though routes to L n MCH 3 complexes are well-established, utilizing highly efficient, commercially available reagents, such as CH 3 Li and CH 3 MgBr, for the synthesis [16], analogous routes to of L n MCF 3 derivatives are not straightforward as it is not similarly efficient and easy to access trifluoromethylating reagents. This results in relatively small L n MCF 3 complexes compared with L n MCH 3 ones [16].…”

High-Throughput Reactivity Exploration for Extended Databases of Transition Metal Catalysts

“…80 Such compounds, on the other hand, receive increasing attention for their utility for the field of fluoro-organic synthesis. 81,82 For example, [Cu]-RF compounds are utilized as the stoichiometric reagents for perfluoroalkyl transfer to organic substrates. [83][84][85][86] Recently, there is much attention to transition-metal-catalyzed (with such metals as Cu, Ni, Pd) C-RF (where RF is usually CF 3 ) bond-forming reactions 87,88 providing a route to various valuable fluorinated pharmaceuticals and agrochemicals.…”

“…[83][84][85][86] Recently, there is much attention to transition-metal-catalyzed (with such metals as Cu, Ni, Pd) C-RF (where RF is usually CF 3 ) bond-forming reactions 87,88 providing a route to various valuable fluorinated pharmaceuticals and agrochemicals. 81,82,89 Daniels et al discussed the synthesis, characterization and reactivity of several bi-and tridentate, N-ligated manganese carbonyl trifluoromethyl complexes. 80 All these complexes feature elongated Mn-CCF 3 bonds suggesting the lability of the moiety, which could potentially be exploited for the transfer or insertion of the CF 3 group into organic substrates.…”