(Aminotroponiminato)yttrium Amides as Catalysts in Alkyne Hydroamination

Abstract

The synthesis and characterization of the mono- and bis(N-isopropyl-2-(isopropylamino)troponiminato)yttrium amides [(iPr)2ATI]Y[N(SiMe3)2]2 and [(iPr)2ATI]2Y[N(SiMe3)2], with the corresponding chloro precursors [[(iPr)2ATI]YCl2(THF)2]2 and [(iPr)2ATI]2YCl as starting materials, is reported together with their application as precatalysts for the hydroamination/cyclization of aminoalkynes.

Modular N,O‐Chelating Ligands: Group‐4 Amidate Complexes for Catalytic Hydroamination

“…[36] Figure 5. Bridging amidates forming lantern-type Pt dimers (8) or head-to-head complexes (9). Dirhodium(II) carboxamidates (10) used in metal carbene transformations.…”

“…Moreover, the most active species (Entry 5) is more active then both the corresponding Cp complex, and Ti(NMe 2 ) 4 . As a further comparison to Ti(NMe 2 ) 4 , a more challenging intramolecular substrate was attempted; see Equation (9). (9) In this case our system went to completion within 3 h at 40°C whereas use of Ti(NMe 2 ) 4 only went to 30 % completion in the same time period.…”

“…[1] However, there are several limitations associated with the modification of Cp, leading to extensive research into broadly applicable non-Cp-based ligand sets in which ligand tuning is more easily accomplished. [2,3] Examples of these classes of ligands have included, but are not restricted to, amidinates, [4][5][6][7][8] troponiminates, [9,10] guanidinates, [11][12][13] sulfonamides, [14,15] nitrogen-based ligands [16][17][18] and chelating nitrogen and oxygen ligand sets. [19][20][21] In surveying the literature, it became apparent that while many [ elaborate ligand classes have been studied, a very simple group of N,O-chelating molecules, namely deprotonated organic amides (amidates), has been largely overlooked.…”

Amination of Aromatic Olefins with Anilines: A New Domino Synthesis of Quinolines

“…[5] Lately, this methodology has been used for tandem CÀN and CÀC bondforming processes, and this yields products with pyrrolizidine, indolizidine, pyrrole, and pyrazine skeletons. [6] Our approach to the catalytic amination of olefins [7] was based on the use of cationic rhodium complexes in order to enhance the reactivity of the known rhodium halide catalysts.…”

Transition Metal‐Catalyzed Asymmetric Hydroamination of Alkenes (AHA)

“…[10] The mechanism of the hydroamination/cyclization [11,12] proceeds through a rare earth metal-amido species, which is formed upon protonolysis of a rare earth metal-amido or -alkyl bond in the precatalyst (Scheme 1). The first step of the catalytic cycle involves insertion of the olefin into the rare earth metal-amido bond with a seven-membered chair-like transition state (for n ¼ 1).…”