Zinc–zinc bonded decamethyldizincocene Zn2(η5-C5Me5)2 as catalyst for the inter- and intramolecular hydroamination reaction

Abstract

The Zn-Zn bonded compound [(η(5)-Cp*)(2)Zn(2)] was investigated as catalyst for the inter- and intramolecular hydroamination reaction. High reaction rates under mild conditions were observed. This is the first application of a Zn-Zn bonded compound as catalyst.

Ethyl‐Zinc(II)‐Cation Equivalents: Synthesis and Hydroamination Catalysis

“…Recently,s omeo fu sr eported an intermolecularh ydroamination reactionc atalyzed by [(h 5 -Cp*) 2 Zn 2 ], [Cp* 2 Zn],a nd ZnEt 2 , 1.943(6)114.6(6) Et-Zn-Et [25] (exp./calc. MP2/def2-QZVPP)1 .948 (5) 11 Cl 11 ] À ·(C 6 H 6 ) [3] 1.964 (6) [29,30] All compounds showed high reactionr ates under mild conditions and ag ood functional group tolerance for the addition of aniline derivatives to primary alkynes. As catalytic species for these and othera lkyl zinc catalyzed reactions, ac ationic species [RZn] + is anticipated.…”

“…Intermolecular hydroamination of anilines and alkynes catalyzed by 4 (values in italic are given fort he catalyst system ZnEt 2 /[PhNMe 2 H][B(C 6 F 5 ) 4 ]f or comparison). [a],[30] …”

A multicentre-bonded [ZnI]8 cluster with cubic aromaticity

“…Among the various bonding types, metal-metal (M-M) bonding has been one of the most important themes in inorganic chemistry since Cotton et al 3 [11][12][13][14][15][16][17][18][19][20][21][22][23] . However, these studies focus on the [Zn I 2 ] 2 þ dimeric species that are not sufficiently stable in air 11 .…”

Cationic Zinc Organyls as Precatalysts for Hydroamination Reactions

“…In addition, the triple‐decker complex 2 was used as a precatalyst in intermolecular hydroamination reactions of phenylacetylenes with aniline derivatives (see below, Table 2). The hydroamination of phenylacetylene with 2,4,6‐trimethylaniline was chosen as a test reaction because this reaction also proceeds at room temperature using the zinc organyls [ZnCp* 2 ] ( 1 ), [Zn 2 Cp* 2 ], or ZnEt 2 as precatalysts 7a,b. On applying 2.5 mol % of complex 2 and 40 equivalents each of 2,4,6‐trimethylaniline and phenylacetylene, a quantitative conversion of phenylacetylene was achieved after a reaction time of two days in an NMR‐scale experiment at room temperature.…”

“… Precatalysts for zinc‐catalyzed hydroamination reactions: a) aminotroponiminato zinc complex; b) β‐diketiminato zinc complex; c) zinc complex with phenalenyl‐based N,N donor ligand; d) zincocene [ZnCp* 2 ] ( 1 ); e) dizincocene [Zn 2 Cp* 2 ] 4b. 5a, 6a, 7a,b …”