Antoine Simonneau

Tracking gold acetylides in gold(I)-catalyzed cycloisomerization reactions of enynes

The intermediacy of gold acetylides in the gold(I)-catalyzed cycloisomerization of enynes was questioned. While dinuclear gold complexes are observed under electrospray ionization conditions, the solution reactivity of gold acetylides also leads to the conclusion of their high affinity for the second coordination of a gold moiety, leading to dinuclear gold complexes. However, the involvement of gold acetylides and the corresponding diaurated species in the elementary steps of cycloisomerization mechanisms of enynes appears unlikely.

Combination of gold catalysis and Selectfluor for the synthesis of fluorinated nitrogen heterocycles

Summary We herein report the synthesis of 3-fluoro-2-methylene-pyrrolidine (3a) and -piperidine (3b) from 1,5- and 1,6-aminoalkynes, respectively, using a combination of a gold-catalyzed hydroamination reaction followed by electrophilic trapping of an intermediate cyclic enamine by Selectfluor. Careful attention was paid to the elucidation of the mechanism and Selectfluor was suggested to play the double role of promoting the oxidation of gold(I) to a gold(III) active species and also the electrophilic fluorination of the enamine intermediates.

Group 6 Transition-Metal/Boron Frustrated Lewis Pair Templates Activate N2 and Allow its Facile Borylation and Silylation.

The reaction of trans-[M(N2 )2 (dppe)2 ] (M=Mo, 1Mo , M=W, 1W ) with B(C6 F5 )3 (2) provides the adducts [(dppe)2 M=N=N-B(C6 F5 )3 ] (3) which can be regarded as M/B transition-metal frustrated Lewis pair (TMFLP) templates activating dinitrogen. Easy borylation and silylation of the activated dinitrogen ligands in complexes 3 with a hydroborane and hydrosilane occur by splitting of the B-H and Si-H bonds between the N2 moiety and the perfluoroaryl borane. This reactivity of 3 is reminiscent of conventional frustrated Lewis pair chemistry and constitutes an unprecedented approach for the functionalization of dinitrogen.

Enhanced Activation of Coordinated Dinitrogen with p-Block Lewis Acids

This Concept article highlights recent research on Lewis acid adducts of dinitrogen complexes, including our contributions. After a reminder of the early works, it is demonstrated that such kind of species offers a new platform for dinitrogen functionalization as well as valuable models for the understanding of elementary steps of (bio)catalytic cycles. When possible, parallels regarding this mode of activation from the orbital point of view are drawn between the different systems discussed herein.