为提高金属的活性,采用不同的纳米金属作水相Barbier-Grignard型反应的促进剂,通过还原方法制备球状纳米Sn、管状纳米Bi,通过溶剂分散法制备球状纳米In。在水相中化学计量纳米锡(铋或铟)成功地促进1 mmol苯甲醛与1.5~2.0mmol烯丙基(或烯丁基)溴反应,在短时间内得到了高产率的高烯丙醇。反应的活性、区域选择性、非对映选择性受不同种类纳米金属的影响。纳米锡促进的烯丁基化反应主要得到以anti-异构体为主的γ型产物;纳米铋促进的烯丁基化反应主要得到以syn-异构体为主的γ型产物;纳米铟促进醛和烯丁基溴的烯丁基化反应,得到了以anti-异构体为主的γ型产物。
In order to improve the activity of metal, different nano-metals were used as the promoting agents of aqueous Barbier-Grignard type reaction. Globular Sn nanoparticle and Bi uanotube were prepared through reduction methods, and globular In nanoparticle was synthesized through the solvent dispersion method. Stoichiometrie Tin nanoparticle or Indium nanoparticle or Bismuth nanotube successfully mediated Barbier-Grignard reaction of 1 mmol benzaldehyde with 1.5 - 2.0 mmol allyl ( or crotyl) bromide in water to afford the corresponding homoallylic alcohols in good to quantitative yields in a short time respectively. The reaction activity, regioslectivity and diastereoselectivity of crotylation reaction could be influened by different nano-metals. Indium nanoparticles promoted the allylations of aldehydes with croty] bromide to give exclusive y-adducts with dominant anti-isomers. Tin nanoparticles promoted the allylations of carbonyl compounds with crotyl bromide, and gave most y-adducts with dominant anti-isomers. Bismuth nanotube promoted the allylations of aromatic aldehydes with crotyl bromide, to give most y-adducts with dominant syn-isomers.