Allyl, amidinium and cyclopropenyl cations from the reactions of primary and secondary amines with pentachlorocyclopropane

Abstract

The action of secondary amines on c-C3HC15 is a simple new route t o aminocyclopropenyl ions, whereas primary amines cause ring opening t o an ally1 cation, e.g. [(Bu~HN)~CCHC(NHBU~)~]+ identified crystallographically, which is reversibly protonated at the central carbon to become a bis(amidinium) dication.

Divalent Carbon(0) Chemistry, Part 2: Protonation and Complexes with Main Group and Transition Metal Lewis Acids

“…no compound preferentially takes place at a carbon atom formally having two double bonds in the neutral form and not at the nitrogen atom. [34] The theoretical finding is supported by the X-ray analyses of 8-H + [32] and 8-(H + ) 2 .…”

“…[26] Experimental values have also been reported for the protonated compounds 3-H + , [27] 9-H + [28] and for the diprotonated species 2-(H + ) 2 [29] and 3-(H + ) 2 , [30] as well as for substituted analogues of 7-H + , [31] 8-H + [32] and 8-(H + ) 2 .…”

“…[4] The experimental observations and our theoretical investigations of divalent carbon(0) compounds [1,5] indicate that the donor-acceptor chemistry of 1-8 may lead to surprising new discoveries which should be studied with experimental and theoretical methods.…”

“…The data for the other compounds are not shown because they do not significantly contribute to the bonding analysis. We also show the EDA results for the metal-CO bonds of W(CO) 6 and Ni(CO) 4 for comparison. [53] The calculated energy terms suggest that the N-W(CO) 5 bonds have more pronounced electrostatic than covalent character.…”

Carbodiylides C(ECp*)2 (E=B–Tl): Another Class of Theoretically Predicted Divalent Carbon(0) Compounds

“…Doubly protonated TAAs are stable species that have been structurally characterized by X-ray analysis. [16] The very strong nucleophilicity of the central carbon atom of the TAAs also comes to the fore by the observation that they easily react with CO 2 , yielding stable donor-acceptor complexes, which feature a [(R 2 N) 2 C] 2 C!CO 2 donor-acceptor bond. [17] It was suggested that the (quasi)linear TAAs should be considered as "hidden" divalent carbon(0) compounds because of their aptitude to serve as double Lewis base in chemical reactions.…”