西北农林科技大学：《有机化学 Organic chemistry》课程PPT教学课件（2014）Chapter 07 Alkyl Halides Nucleophilic Substitution and Elimination

有机化学ORGANIC CHEMISTRY 主讲：主俊儒870928290) 理学院应化系理科楼2层206 Organic Chemistry,6h Edition L.G.Wade,Jr. Chapter7 AlRylHalides: Nucleophilic Substitution Elimination Key Notes Nucleophilic Substitution,SN1/SN2,Elimination (E1/E2) Nucleophilicity,Leaving group Homework.7-37:7-39:7-40,:7-44(P274

Chapter 7 Alkyl Halides: Nucleophilic Substitution & Elimination Organic Chemistry, 6h Edition L. G. Wade, Jr. Key Notes Nucleophilic Substitution, SN1/SN2, Elimination（E1/E2） Nucleophilicity, Leaving group 有机化学ORGANIC CHEMISTRY 主讲：王俊儒 87092829(O) 理学院应化系理科楼2层C206 Homework：7-37 ; 7-39; 7-40 ; 7-44（P274）

自秋不转大对 Content 花中就 Preparation and physical properties Nucleophilic substitution Factors affecting SN2 versus SN1 reactions Elimination:Elimination versus substitution ■g Reactions of alkyl halides Organometallic reactions

Content ◼Preparation and physical properties ◼Nucleophilic substitution ◼Factors affecting SN2 versus SN1 reactions ◼Elimination：Elimination versus substitution ◼Reactions of alkyl halides ◼Organometallic reactions

Types of Dihalides Primary,Secondary,Tertiary Alkyl Halides R CH,-X R—CH,一X R-CH-X R-C-X methyl halide primary (1)halide secondary (2)halide R tertiary (3)halide 2013 Pearson Education.Inc Br 9-9 -C- a geminal dibromide a vicinal dichloride Geminal dihalide:Two halogen atoms are bonded to the same carbon. Vicinal dihalide:Two halogen atoms are bonded to adjacent carbons

Types of Dihalides Primary, Secondary, Tertiary Alkyl Halides ◼Geminal dihalide: Two halogen atoms are bonded to the same carbon. ◼Vicinal dihalide: Two halogen atoms are bonded to adjacent carbons

Uses of Alkyl Halides Solvents -degreasers and dry cleaning fluid Reagents for synthesis of other compounds Anesthetic:Halothane is CFCHCIBr CHCl3 used originally (toxic and carcinogenic)麻醉剂 In 1847,the Edinburgh obstetrician James Operation of a chloroform inhaler for surgical anesthesia around 1850. Young Simpson first Valves pass the incoming air through used chloroform for cotton dampened with chloroform. general anesthesia Inhalation anesthetics such as during childbirth Halothane,CF3CHBrCl,derive their biological activity from the polar nature of their C-X bonds

Uses of Alkyl Halides ◼Solvents - degreasers and dry cleaning fluid ◼Reagents for synthesis of other compounds ◼Anesthetic: Halothane is CF3CHClBr ⚫CHCl3 used originally (toxic and carcinogenic)麻醉剂 In 1847, the Edinburgh obstetrician James Young Simpson first used chloroform for general anesthesia during childbirth

Uses of Alkyl Halides Freons,chlorofluorocarbons or CFC's Freon 12,CF2Cl2,now replaced with Freon 22, CF2CHCl,not as harmful to ozone layer. Pesticides-DDT banned in U.S. extremely toxic to insects but not as toxic to mammals

Uses of Alkyl Halides ◼Freons, chlorofluorocarbons or CFC’s ⚫Freon 12, CF2Cl2 , now replaced with Freon 22, CF2CHCl, not as harmful to ozone layer. ◼Pesticides – DDT banned in U.S. ⚫extremely toxic to insects but not as toxic to mammals

Uses of Alkyl Halides ■杀虫剂、杀灭蚊子（疟疾） DDT1939年后广泛使用（残留高） Srilanka ●1934-1935150万(8万died) ●1963：仅15例 ●1968-1969第二季度60万例 1972:环境保护组织（EPA) 废除 ■冷却液和喷气燃料推进剂

Uses of Alkyl Halides ◼杀虫剂、杀灭蚊子（疟疾） DDT 1939年后广泛使用（残留高） Srilanka : ⚫1934-1935 150万（8万 died） ⚫1963:仅15例 ⚫1968-1969第二季度60万例 1972：环境保护组织（EPA）废除 ◼冷却液和喷气燃料推进剂

Halogenated Steroids as Anti-Inflammatory and Anti-Asthmatic Agents OH OH OH HO HO Cortisol Budenoside CCH2CH3 SCH2F H30 CCH,CH H.C CCH2CH3 HO HO 0 CH3 Beclomethasone dipropionate Fluticasone propionate An international study published in early 2004 found that fluticasone was effective in reducing asthma-inducing inflammation in babies from one to three years of age,while having no significant effect on their growth

An international study published in early 2004 found that fluticasone was effective in reducing asthma-inducing inflammation in babies from one to three years of age, while having no significant effect on their growth

Plant pathologist Frank Westerlund demonstrates the "bromomethane difference"between strawberries grown in a fumigated plot (right)and those not (left).The latter are withered by verticillium wilt,a fungus. The Dilemma of Bromomethane: Highly Useful but Also Highly Toxic

The Dilemma of Bromomethane: Highly Useful but Also Highly Toxic

Naturally Occurring Organohalides Marine corals secrete organohalogen compounds that act as a feeding deterrent to fish. More than 5000 organohalides have been found to occur naturally,and tens of thousands more surely exist

More than 5000 organohalides have been found to occur naturally, and tens of thousands more surely exist. Naturally Occurring Organohalides

Br Br H Halomon The pentahalogenated alkene halomon has been isolated from the red alga Portieria hornemannii and found to have anticancer activity against several human tumor cell lines. Some naturally occurring organohalides are produced in massive quantities. Forest fires,volcanoes,and marine kelp release up to 5 million tons of CH3CI per year,for example,while annual industrial emissions total about 26,000 tons. Termites are thought to releaseas much as 108 kg of chloroform per year

The pentahalogenated alkene halomon has been isolated from the red alga Portieria hornemannii and found to have anticancer activity against several human tumor cell lines. Some naturally occurring organohalides are produced in massive quantities. Forest fires, volcanoes, and marine kelp release up to 5 million tons of CH3Cl per year, for example,while annual industrial emissions total about 26,000 tons. Termites are thought to releaseas much as 108 kg of chloroform per year