Non-decarbonylative photochemical versus thermal activation of Bu₄N[Fe(CO)₃(NO)] – the Fe-catalyzed Cloke–Wilson rearrangement of vinyl and arylcyclopropanes

Abstract

TBA[Fe] catalyzes the rearrangement of vinyl and arylcyclopropanes under thermal or photochemical conditions.

The Evolution of Fe‐catalyzed Nucleophilic Activation of Acceptor‐substituted Vinyl‐ and Arylcyclopropanes

“…Within the optimization of this side reaction, we realized that the addition of essentially any basic ligand slowed down this interesting conversion . Under optimized conditions, only 2.5 mol% of TBA[Fe] in methylene chloride as a solvent at 40 °C proved necessary to obtain good to excellent yields of the rearrangement products.…”

“…In sharp contrast, irradiation of the reaction mixture under otherwise identical conditions allowed this transformation at room temperature at prolonged reaction times. A selection of examples are shown in Figure …”

“…During the optimization of the photochemical Fe‐catalyzed Cloke‐Wilson rearrangement, we realized that the conversion reached a maximum using light of 415 nm wavelength, a wavelength at which a shoulder is observed in the UV‐Vis spectra of the catalyst . With the help of the quantum chemical tools developed and applied before, we set out to analyze the nature of the activated Fe catalyst (Figure ).…”

“… Schematic energy level diagram, along with CASSCF/def2‐TZVPP equilibrium structures of [Fe(CO) 3 (NO)] …”

The Chemistry of 1‐Acylphosphirane Complexes: A Phosphorus Analogue of the Cloke–Wilson Rearrangement

“…The phosphorus-carbon analogy is mainly based on the similar reactivity of P=Ca nd C=Cd ouble bonds [1] but it is also possible to conceivethe phosphorus analogues of the numerousrearrangements that characterize organic chemistry.O ne of the classical rearrangements driven by the strain of the cyclopropane ring involves the transformation of cyclopropylketones into dihydrofurans, the so-called Cloke-Wilson rearrangement. [2] We wanted to investigate the chemistry of acylphosphinidenec omplexes [RC(O)CÀW(CO) 5 ]a nd, in so doing, to expand the already richf ield of phosphinidenec hemistry. [3] This led us to investigate the thermolysis of 1-acylphosphiranes.…”