Synthesis and reactivity of 2-azametallacyclobutanes

Abstract

2-Azametallacyclobutanes have been reported for a number of metals. This Perspective provides a brief overview of 2-azametallacyclobutanes, focusing on complexes in which the ring nitrogen is anionic (amido).

Paramagnetic DOSY: An Accurate Tool for the Analysis of the Supramolecular Interactions between Lanthanide Complexes and Proteins

“…To the best of our knowledge,n os ystematic investigation has been reportedt od ate to address the potential of these complexes as suitable probesf or diffusion NMR.I ndeed, amongt he rare casesr eported in this field, most of the time diamagneticL ao r Lu systems were studied, [13] although DOSY on Nd, Sm, and Eu complexes have also been described. To the best of our knowledge,n os ystematic investigation has been reportedt od ate to address the potential of these complexes as suitable probesf or diffusion NMR.I ndeed, amongt he rare casesr eported in this field, most of the time diamagneticL ao r Lu systems were studied, [13] although DOSY on Nd, Sm, and Eu complexes have also been described.…”

“…To that end, we report herein the implementationo fd iffusion-ordered NMR spectroscopy (DOSY) to probe av arietyo f dynamics ystems involving lanthanide complexes. To the best of our knowledge,n os ystematic investigation has been reportedt od ate to address the potential of these complexes as suitable probesf or diffusion NMR.I ndeed, amongt he rare casesr eported in this field, most of the time diamagneticL ao r Lu systems were studied, [13] although DOSY on Nd, Sm, and Eu complexes have also been described. [14] The approach that is [ presented takes benefito fi )the strongp seudo-contact shift effect resulting in ad isplacemento ft he 1 HNMR signals of paramagnetic lanthanide complexes,l eadingt oaclear separation of these signals andt hose of the protein, and ii)the large differenceo fm olecular weightb etween the complexa nd its adduct with aprotein, which is expected to induceasignificant variation of the observed diffusion rate upon association.…”

The Dawn of Functional Organoarsenic Chemistry

“…However, investigations of “arsoles” from the viewpoint of materials science remain to be performed, although some arsole derivatives were synthesized up to the 1960s . If studies on pnictogen‐type heteroles are performed by experimental means, pyrrole, phosphole, stibole, and bismole derivatives are prepared, but their arsenic analogues tend to be excluded. Nevertheless, computational studies have constantly predicted the intrinsic natures of arsoles: frontier orbitals, inversion energies, and aromaticity .…”

“…However,i nvestigations of "arsoles" from the viewpoint of materials science remaint ob ep erformed, although some arsole derivatives were synthesized up to the 1960s. [4][5][6][7][8] If studies on pnictogen-type heteroles are performed by experimental means, pyrrole, [9][10][11][12][13] phosphole, [14][15][16][17] stibole, [18,19] and bismole [20][21][22] derivatives are prepared, but their arsenic analoguest end to be excluded.N evertheless, computational studies have constantly predicted the intrinsic natures of arsoles: frontier orbitals, inversion energies, and aromaticity. [23][24][25][26][27][28][29][30] Ta king into consideration growingi nterest in heavy-element-containing molecules, [31] studies on functional organoarsenic chemistry is attractive thanks to the air-stable trivalent state [3] and possibility of the heavy-atom effect.…”

Formation of Substituted Oxa‐ and Azarhodacyclobutanes

“…Oxa-and azametallacyclobutanes are frequently proposed as intermediates in chemical reactions. [4][5][6] For example, oxametallacyclobutanes-commonly referred to as metallaoxetanes-have been invoked as early as 1900 in the oxymercuration of olefins. [7] But it was not before the 1970s that significant attention was drawn to their possible role as reaction intermediates.…”