一种水溶性氢氧根钌配合物的合成及其对乙腈的催化水化作用

Synthesis of a Water-Soluble Ruthenium Hydroxide Complex and Its Role in Catalytic Hydration of Acetonitrile

以RuCl3·3H2O为原料合成了水溶性钌配合物[(bipy)2Ru(H2O)2](OTf)2(bipy=2,2'-bipyridine,Otf-=triflate),利用DBU(1,8-Diazabicyclo[5.4.0]undec-7-ene)脱质子化合成了水溶性氢氧根配合物[(bipy)2Ru(H2O)(OH)](OTf).研究了[(bipy)2Ru(H2O)(OH)](OTf)催化水化乙腈生成乙酰胺的反应.机理研究表明,催化循环的关键中间体为氧配位的酰亚胺配合物[(bipy)2Ru(CH3CN)(OCMe=NH)]+,经过生成[(bipy)2Ru(κ2-N,O-NH=CMeN=CMeO)]+、水亲核进攻开环生成{(bipy)2Ru[NH=C(OH)Me](OCMe=NH)}+、乙腈取代其NH=C(OH)Me配体产生乙酰胺,同时再生成[(bipy)2Ru-(CH3CN)(OCMe=NH)]+完成催化循环.

In the presence of DBU（1,8-Diazabicycloundec-7-ene）,a novel water-soluble hydroxide ruthenium complex [（bipy）2Ru（H2O）（OH）]（OTf） was synthesized by deprotonation of [（bipy）2Ru（H2O）2]-（OTf）2（bipy=2,2＇-bipyridine,Otf-=triflate）,which was prepared using RuCl3·3H2O as starting material.The hydration of acetonitrile to form acetamide catalyzed by [（bipy）2Ru（H2O）（OH）]（OTf） was studied.O-bonded imido complex [（bipy）2Ru（N≡CCH3）（OCMe=NH）]＋ is postulated to be the key intermediate,which then undergoes nucleophilic attack at the carbon atom of nitrile ligand to form [（bipy）2Ru（k2-N,ONH=CMeN=CMeO）]＋.Ring-opening nucleophilic attack of [（bipy）2Ru（k2-N,O-NH=CMeN=CMeO）]＋by water produces {（bipy）2Ru[NH=C（OH）Me]（OCMe=NH）}＋.The displacement of NH=C（OH）Me ligand in the latter complex by acetonitrile forms acetamide,and regenerates [（bipy）2Ru（N≡CCH3）-（OCMe=NH）]＋ to fulfill catalytic cycle.