N-Heterocyclic silylene/germylene ligands in Au(i) catalysis

Abstract

<p>N-Heterocyclic carbene, silylene and germylene ligand-based cationic Au(<sc>i</sc>)–arene complexes were prepared and employed as catalysts in the glycosidation reaction.</p>

Triflic Imide‐Catalyzed Glycosylation of Disarmed Glycosyl ortho‐Isopropenylphenylacetates and ortho‐Isopropenylbenzyl Thioglycosides

“…The data are identical with those in the literature. [45] Methyl 4-O-(2,3,4,6-tetra-O-benzoyl-β-D-mannopyranosyl)-2,3-di-O-benzoyl-6-benzyl-α-D-glucopyranoside (7 b)…”

Coinage Metal Complexes of Germylene and Stannylene

“…Recently, we have isolated [PhC(N t Bu) 2 GeN(TMS) 2 ]-stabilized cationic gold(I) complexes, where benzene ( 51 ) and toluene ( 52 ) are present in η 2 binding fashion. 23 Complexes 51 and 52 were further used as efficient catalysts for glycosidation reaction. Moreover, 52 was found to be equally efficient like a silylene counterpart for the disaccharide formation.…”

Cyclometallation of Heavier Tetrylenes: Reported Complexes and Applications in Catalysis

“…[17a] The iron(II) complex 28, which features two coordination variants of ligand E, is an efficient catalyst for the hydroboration of carbonyl compounds at room temperature. [19] Table 4 shows the catalytic results for the hydroboration of ketones (entries 1-16) and aldehydes (entries [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] with HBpin in THF (other solvents were found to be less efficient). [19] Complex 28 was able to hydroborate a plethora of para-and meta-substituted acetophenones (entries 1-12), rendering conversions close to or higher than 90 %, except for substrates featuring strong electron donating groups (entries 5 and 12).…”

“…[7,8] On the other hand, heavier tetrylenes (HTs) have been used as ligands in transition metal chemistry [9,10] since the 1970s. [9i-k,11] Recently, new generations of HTs, particularly those donorstabilized by amidinato and other chelating moieties, have been recognized as versatile ligands in homogeneous catalysis, [10] capable to promote processes such as (a) Suzuki, [12a] Heck, [12a] Kumada, [12b,c,e] Neghishi [12c] and Sonogashira [12d] couplings, (b) alkene hydrosilylations, [13] (c) ketone hydrosilylations, [14] (d) alkyne-azide "click" cycloadditions, [15] (e) olefin metathesis, [16] (f) ketone hydrogenations, [17] (g) arene and heterocycle borylations, [18] (h) H/D exchange reactions, [17a,18a] (i) ketone hydroborations, [19] (j) N 2 silylation, [20] (k) amide reductions, [21] (l) carbonyl cyanosilylations, [22] (m) [2 + 2 + 2] cycloadditions, [23] (n) alkene hydroformylations, [24] (o) Buchwald-Hartwig aminations, [25] (p) alkene [26a,b] and alkyne [26c] hydrogenations, (q) CÀ H functionalization of arylpyridines, [12e,27] (r) glycosidation reactions, [28] (s) lactide [29a] and lactone [29b] polymerizations, (t) cyclodimerization of alkynes, [30] etc. Noteworthy, some of these donor-stabilized HTs have demonstrated to be very strong electron-donating ligands, [31,32] even stronger than alkyl phosphanes and many NHCs, [32] a property that is crucial to develop effective and stable catalysts.…”