厦门大学化学化工学院：《有机化学》课程教学资源（课件讲稿，双语版）第十二章 由羰基化合物生成醇氧化还原反应和有机金属化合物（12-5）有机金属化合物

ORGANIC CHEMISTRY Chapter 12 12.5 Organometallic Compounds 有机金属化合物 Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 12.5 Organometallic Compounds 有机金属化合物

ORGANIC CHEMISTRY Chapter 12 o Compounds that contain carbon-metal bond are called organometallic compounds -C: M Primarily ionic Primarily covalent (M=Na or K)(=Mg or Li)(M=Pb, Sn, Hg, or TD) o The reactivity of organometallic compounds increases with the percent ionic character of the carbon-metal bond o Rli and rmgX are of great importance in organic syntheSIs Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 Compounds that contain carbon-metal bond are called organometallic compounds. C M C M δ− δ+ C M Primarily ionic Primarily covalent (M = Na+ or K+ ) (M = Mg or Li) (M = Pb, Sn, Hg, or Tl) The reactivity of organometallic compounds increases with the percent ionic character of the carbon-metal bond. RLi and RMgX are of great importance in organic synthesis

ORGANIC CHEMISTRY Chapter 12 12.6 Preparation of Organolithium and Organomagnesium Compounds 有机锂和有机镁化合物的制备 Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 12.6 Preparation of Organolithium and Organomagnesium Compounds 有机锂和有机镁化合物的制备

ORGANIC CHEMISTRY Chapter 12 12. 6A Organolithium Compounds o Organolithium compounds are often prepared by th reduction of organic halides with lithium metal R-X+2Li Eto RLI LiX or ar-X (or Arli Reactivity: RI>RBr> RcI Et,o CHr CH,CH, CH2 Br 2 Li CH2CHCH CHoLi + LiBr 口10°C Butyl bromide Butyllithium (80~909%) Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 12.6A Organolithium Compounds Organolithium compounds are often prepared by th reduction of organic halides with lithium metal. R X + 2 Li RLi + LiX (or Ar X ) (or ArLi) Et2O Reactivity: RI > RBr > RCl CH3CH2CH2CH2Br + 2 Li Et2O ￾10°C CH3CH2CH2CH2Li + LiBr Butyl bromide Butyllithium (80 ~ 90%)

ORGANIC CHEMISTRY Chapter 12 12.6B Grignard Reagents o Grignard reagents are usually prepared by the reaction of an organic halide and magnesium metal in an ether solvent Eto R-X + Mg RMgX G orignal Et,o or thf reagents Ar-X+ Mg ArMeX Et,o CH3-I Mg CH2Mgl 35°C ethylmagnesium iodide THE C6H5-CI+ M g-△ CkHsMeCI Phenylmagnesium chloride Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 12.6B Grignard Reagents Grignard reagents are usually prepared by the reaction of an organic halide and magnesium metal in an ether solvent. R X Ar X + Mg Et2O RMgX + Mg Et2O or THF ArMgX Grignard reagents CH3 I + Mg Et2O CH3MgI 35°C Methylmagnesium iodide C6H5 Cl + Mg THF C6H5MgCl Phenylmagnesium chloride

ORGANIC CHEMISTRY Chapter 12 12. 7 Reactions of Organolithium and Organomagnesium Compounds Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 12.7 Reactions of Organolithium and Organomagnesium Compounds

ORGANIC CHEMISTRY Chapter 12 12.7A Reactions with Compounds Containing Acidic hydrogen Atoms o Grignard reagents and organolithium compounds are very strong bases. They react with any compounds that has a hydrogen attached to an electronegative atom such as oxygen, nitrogen, or sulfur HOH RH HO+ Mgt+X ROH RMgX RH+RO Mg+ X R'C≡CH RH+RC≡CMgx δ-8 RLi+RC≡CH—-RH+RC≡CL Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 12.7A Reactions with Compounds Containing Acidic Hydrogen Atoms Grignard reagents and organolithium compounds are very strong bases. They react with any compounds that has a hydrogen attached to an electronegative atom such as oxygen, nitrogen, or sulfur. RMgX R'C CH HOH R'OH RH RH RH + + + HO + Mg2+ + X R'O + Mg2+ + X R'C C MgX δ− δ+ RLi + R'C CH R'C C Li δ− δ+ RH +

ORGANIC CHEMISTRY Chapter 12 12. 7B Reactions of Grignard Reagents with Oxiranes(epoxides) 0O +_.ht RMgX+H2C—CH2—-RCH2CH2OMgX RCH2 CH2OH (1)Et2O CH5MgBr+HC—CH CkHCHoCHOH 2(2)H2OH (lEtO C6 Hs MgBr+H2C—CH-CH3 CkHsCHoCHCH (2)H2O/H OH Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 12.7B Reactions of Grignard Reagents with Oxiranes (Epoxides) RMgX + H2C CH2 O RCH2CH2O MgX H+ RCH2CH2OH C6H5MgBr + H2C CH2 O C6H5CH2CH2OH (1) Et2O (2)H2O/H+ C6H5MgBr + H2C CH O CH3 (1) Et2O (2)H2O/H+ C6H5CH2CHCH3 OH

ORGANIC CHEMISTRY Chapter 12 12. 7C Reactions of Grignard Reagents with Carbonyl Compounds (1)Et2O RMgX +C=O R-C-OH Mgx2 (2)H2O/H Mechanism R:MgX+C0→→R-C-0MgX R-C-o MgX +H-o-H R-C-OH +0-H+ MgX H Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 12.7C Reactions of Grignard Reagents with Carbonyl Compounds RMgX + C O (1) Et2O (2)H2O/H+ R C OH + MgX2 Mechanism Mechanism R MgX+ C O δ− δ+ R C O MgX R C O MgX H O H H + R C OH O H H + + MgX

ORGANIC CHEMISTRY Chapter 12 12.8 Alcohols from Grignard Reagents Department of Chemistry, Xiamen University

ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 12 12.8 Alcohols from Grignard Reagents