摘要/Abstract
以双齿P，N-配体8-（二苯基膦基）喹啉（DPPQ）为支撑配体的钌亚丙二烯基配合物[RuCl（=C=C=CR2）（DPPQ）2]-[BPh4]（3a：R=苯基；3b：CR2=FN=亚芴基）可由双核钌配合物[Ru（μ-Cl）（DPPQ）2]2[BPh4]2（1）分别与过量的1，1-二苯基炔丙醇（2a）或9-乙炔-9-芴醇（2b）反应得到.配合物3易与肼在室温下反应生成丙烯腈的钌配合物[RuCl（N≡C-CH=CR2）（DPPQ）2][BPh4]（4a：R=苯基；4b：CR2=FN=亚芴基），该反应涉及肼对亚丙二烯基配体α-碳原子的分子间亲核进攻，是首例肼对金属亚丙二烯基加成生成丙烯腈的反应.配合物4与过量的丙炔醇2反应可释放出3，3-二苯基丙烯腈（5a）或3-芴基丙烯腈（5b），并再生亚丙二烯基配合物3.此外，初步考察了配合物1对端基炔丙醇与肼反应生成丙烯腈的催化活性，结果表明该催化反应的确可以进行，但是得到的丙烯腈产物的产率不高.尽管结果不是很理想，但是这些研究表明可望发展端基炔丙醇与肼经由过渡金属亚丙二烯基中间体转化为丙烯腈的新催化反应.
关键词: 钌, 亚丙二烯基, 炔烃, 肼, 腈
The cationic ruthenium allenylidene complexes[RuCl(=C=C=CR2)(DPPQ)2] [BPh4] (3a:R=Ph; 3b:CR2=FN=9H-fluoren-9-ylidene) supported by the heterobidentate P,N-donor ligand 8-(diphenylphosphanyl)quinoline (DPPQ) have been synthesized from the reactions of the dimeric complex[Ru(μ-Cl)(DPPQ)2]2[BPh4]2 (1) with excess 1,1-diphenylprop-2-yn-1-ol (2a) or 9-ethynyl-9H-fluoren-9-ol (2b), respectively. Addition of hydrazines to the ruthenium-allenylidenes 3 led to the facile formation of ruthenium-bound acrylonitrile complexes[RuCl(N≡C-CH=CR2)(DPPQ)2] [BPh4] (4a:R=Ph; 4b:CR2=FN) at room temperature. This reaction involves the intermolecular nucleophilic attack of hydrazines at the Cα atom of the allenylidene ligand, which represents the first examples of addition of hydrazines to metal-allenylidenes affording acrylonitrile derivatives. Reaction of acrylonitrile complex 4 with an excess of propargyl alcohols 2a or 2b (4 equiv.) could release the organic acrylonitriles 3,3-diphenylacrylonitrile (5a) or 2-(9H-fluoren-9-ylidene)-acetonitrile (5b) along with regeneration of allenylidene complex 3. In addition, the catalytic activity of 1 for the transformation of terminal propargyl alcohols and hydrazines into acrylonitriles has been investigated preliminarily. The results showed that the catalytic reaction did proceed to give the desired acrylonitrile products, albeit the yield not good. Nevertheless, our results of the catalytic reactions demonstrated that it is very promised to develop new catalytic reactions for the transformation of terminal propargylic alcohols and hydrazines into acrylonitriles via allenylidene intermediates.
Key words: ruthenium, allenylidene, alkyne, hydrazine, nitrile
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