Transformations of alkene and alkyne substrates relevant to π-Lewis acid catalysis have been performed using low-valent Ga(I) species for the first time. [Ga(I)(PhF)₂]⁺[Al(OR^F)₄]⁻ and gallium dichloride (i. e. [Ga(I)]⁺[GaCl₄]⁻) proved to be efficient catalysts for cycloisomerizations, Friedel-Crafts reactions, transfer hydrogenations, and reductive hydroarylations. Their activity is compared to more common Ga(III) complexes. This study shows that even the readily available and yet overlooked gallium dichloride salt can be a more active π-Lewis acid catalyst than gallium trichloride or other Ga(III) species.

中文翻译：

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低价阳离子镓（I）配合物作为π酸的催化用途

首次使用低价Ga（I）物种进行了与π-路易斯酸催化有关的烯烃和炔烃底物的转化。[Ga（I）（PhF）₂ ] ⁺ [Al（OR ^F）₄ ] ^-和二氯化镓（即[Ga（I）] ⁺ [GaCl ₄ ] ^-）被证明是有效的环异构化催化剂，Friedel-Crafts反应，转移氢化和还原性氢芳基化。将它们的活性与更常见的Ga（III）配合物进行比较。这项研究表明，即使容易获得但仍被忽视的二氯化镓盐也可能比三氯化镓或其他Ga（III）物种具有更高的活性π-路易斯酸催化剂。