Bis(allyl)gallium Cation, Tris(allyl)gallium, and Tetrakis(allyl)gallate: Synthesis, Characterization, and Reactivity
摘要:
A series of cationic, neutral, and anionic allylgallium complexes has been isolated and fully characterized. It includes neutral [Ga(eta(1)-C3H5)(3)(L)] (1, L = THF; 2, L = OPPh3), cationic [Ga(eta(1)-C3H5)(2)(THF)(2)](+)[A](-) (3, [A](-) = [B(C6F5)(4)]; 4, [A]- = [B(C6H3Cl2)(4)](-)), as well as anionic [Cat](+)[Ga(eta(1)-C3H5)(4)](-) (5, [Cat](+) = K+; 6, [Cat](+) = [K(dibenzo-18-c-6](+); 7, [Cat](+) = [PPh4](+)). Binding modes of the allyl ligand in solution and in the solid state have been studied comparatively. Single crystal X-ray analyses revealed a fourcoordinate neutral gallium center in 2, a five-coordinate cationic gallium center in 4 and [4.THF], and a four-coordinate anionic gallium center with a bridging mu(2)-eta(1):eta(2) coordination mode of the allyl ligand in 6. The reactivity of this series of allylgallium complexes toward benzophenone and N-heteroaromatics has been investigated. Counterion effects have also been studied. Reactions of 1 and 5 with isoquinoline revealed the first examples of organogallium complexes reacting under 1,2-insertion with pyridine derivatives.
The Bis(allyl)bismuth Cation: A Reagent for Direct Allyl Transfer by Lewis Acid Activation and Controlled Radical Polymerization
作者:Crispin Lichtenberg、Fangfang Pan、Thomas P. Spaniol、Ulli Englert、Jun Okuda
DOI:10.1002/anie.201206782
日期:2012.12.21
A positive effect: The bis(allyl)bismuth cation (see picture) in [Bi(C3H5)2(thf)2][B(C6H3Cl2)4] is superior to neutral tris(allyl)bismuth in the additive‐free allylation of unsaturated C‐heteroatom functionalities and the controlled living radical polymerization of activated olefins.
积极作用:[Bi(C 3 H 5)2(thf)2 ] [B(C 6 H 3 Cl 2)4 ]中的双(烯丙基)铋阳离子(见图)优于中性三(烯丙基)铋参与不饱和C杂原子官能团的无添加剂烯丙基化反应和活性烯烃的受控活性自由基聚合。