Hydroamination of alkynes with aromatic amines catalyzed by digallane (dpp-bian)Ga—Ga(dpp-bian)

Gallium “Shears” for C=N and C=O Bonds of Isocyanates

“…(8): Ga(1)ÀGa(1')2 .4270(4),G a(1)ÀN(1) 1.8867 (15), Ga(1)ÀN(2) 2.1497 (15), Ga(1)ÀN(3) 1.9688 (16),O (1)ÀC(37) 1.224(2), N(1)ÀC(1) 1.475(2), N(2)ÀC(2) 1.288(2), N(3)ÀC(37) 1.353(2), C(1)ÀC(2) 1.535(3), C(1)ÀC(37) 1.577(3);N(1)-Ga(1)-Ga(1')132.84 (5), N(1)-Ga(1)-N(2)8 4.06 (6), N(1)-Ga(1)-N(3) 88.32 (7), N(2)-Ga(1)-Ga(1')1 27.55(4), N(3)-Ga(1)-Ga(1')121.75 (5), N(2)-Ga(1)-N(3) 88.50 (7), C(1)-N(1)-Ga(1) 96.98 (11), C(2)-N(2)-Ga(1) 102.14(13), C(37)-N(3)-Ga(1)1 07.76(12). (8): Ga(1)ÀGa(2) 2.4262 (7), Ga(1)ÀN(1)1.893(2),Ga(1)ÀN(2) 2.157(2), Ga(1)ÀN(3) 2.016(2), O(1)ÀC(37) 1.213(3), N(1)ÀC(1) 1.477(3), N(3)À C(37) 1.382(3), N(2)ÀC(2) 1.283(3), C(1)ÀC(2) 1.544(3),C (1)ÀC(37) 1.575(3); N(1)-Ga(1)-Ga(2) 140.25 (7), N(1)-Ga(1)-N(2) 83.48 (8), N(1)-Ga(1)-N(3) 86.32 (9), N(3)-Ga(1)-Ga(2) 116.08 (6), N(2)-Ga(1)-N(3) 85.91 (9), N(2)-Ga(1)-Ga(2) 127.88(5), C(1)-N(1)-Ga(1) 99.05 (14), C(37)-N(3)-Ga(1) 109.33 (16), C(37)-N(3)-S(1) 122.65 (17), C(2)-N(2)-Ga(1) 102.82 (16), C(1)-C(2)-N(2) 117.4(2). pared to those in 3 (N(1)ÀC(1) 1.475(2) )a nd 4 (N(2)ÀC(2) 1.477(3) )may indicatesome ring strain in the former.…”

“…Surprisingly, the acenaphthene‐1,2‐diimine‐based digallane shows reversibility of the addition processes. This feature may enable it to catalyze hydroaminations and hydroarylations of alkynes . On the contrary, substrates amenable to cycloaddition, such as benzylideneacetone, azobenzene, quinones, and SO 2 , do not afford cycloaddition products with 1 .…”

Element‐Ligand Cooperativity with p‐Block Elements

“…The transiently formed enamines underwent tautomerization to the respective imines as final products, which could be obtained in excellent yields; for example, the reaction of 4‐chloroaniline with phenylacetylene within 6 h in refluxing toluene resulted in a quantitative yield (Figure a). Internal alkynes did not undergo this reaction in the presence of 62 . When the scope of the reaction was extended to 1‐aminonaphthalene, a nearly 1:1 mixture of the desired imine and the hydroarylation product of phenylacetylene with the 2‐position C–H bond of 1‐aminonaphthalene was obtained (Figure c).…”

“…Fedushkin, Abakumov and others suggested a GaLC mechanism for these addition reactions, featuring nucleophilic attack at the alkyne GaLC addition products, followed by proton transfer and product elimination (Figure b). [73b] Moskalev et al provided a kinetic study of the hydroamination, in which they identified degradation products of the interaction of 62 with phenylacetylene and aniline and proved them to be catalytically inactive . Dinuclear 64 and mononuclear 66 were also tested for their ability to catalyze hydroaminations and were found active but inferior to 62 .…”

Touches to the Portrait of Academician G.A. Abakumov

“…А.А. Скатова [16], защитившая диссертацию под руководством И.Л. Федюшкина, возглавляет сейчас лабораторию лиганд-промотируемых реакций.…”