CHAPTER EIGHT Nucleophilic Substitution TABLE 8.1 Representative Functional Group Transformations by Nucleophilic Substitution Nucleophile and comments General equation and specific example Alkoxide ion(RO: " )The oxygen atom of a metal alkoxide acts as a >ror+ nucleophile to replace the halogen of an alkyl halide. The product is Alkoxide ion Alkyl halide Ether Halide ion ether (CH3)2 ONa CH3 CH2Br (CH3)2CHCH2 OCH2 CH3+ NaBr Sodium Sodium bromide ether(66%) Carboxylate ion(RC-O: " ) An ester +1A义:一、o+ is formed when the negatively harged oxygen of a carboxylate Alkyl halide Ester Halide ion places the halogen of an alkyl KOC(CH2)16 CH3 CH3 CH2I 9 CH3CH2 OC(CH2) CH3 KI potassium Ethyl Potassium octadecanoate(95%) Hydrogen sulfide ion(HS: ")Use of ydrogen sulfide as a nucleophile ermits the conversion of alkyl hal- Hydrogen sulfide ion Alkyl halide Thiol Halide ion ides to compounds of the type RSH These compounds are the sulfur ana- KSH +CH3 CH(CH,) CH3 etnano CH3 CH(CH2)CH:+ KBr logs of alcohols and are known as 2-Nonanethiol nide ion is usually the Caim Te. e negativ C≡N p Cyanide ion Alkyl halide Alkyl cyanide Halide ion haracter. Use of cyanide ion as a nucleophile permits the extension of a carbon chain by carbon-carbon Nacn+ bond formation The product is an 0-a=D cn+ Nac alkyl cyanide, or nitrile. cyclo Sodium cya chloride chloride Azide ion(N=N=N: )Sodium azide N=N →RN=N=N:+ is a reagent used for carbon-nitro- gen bond formation the product is Azide ion Alkyl halide Alkyl azide Halide ion an alkyl azide 1-propanol- NaN3+ CH3(CH2)4I →CH(CH2)4N3+Nal Sodium Pentyl iodide Pentyl azide Sodium (52%) iodide Back Forward Main MenuToc Study Guide ToC Student o MHHE Website304 CHAPTER EIGHT Nucleophilic Substitution TABLE 8.1 Representative Functional Group Transformations by Nucleophilic Substitution Reactions of Alkyl Halides Nucleophile and comments Cyanide ion (:C PN:) The negatively charged carbon atom of cyanide ion is usually the site of its nucleophilic character. Use of cyanide ion as a nucleophile permits the extension of a carbon chain by carbon–carbon bond formation. The product is an alkyl cyanide, or nitrile. (Continued) Alkoxide ion (RO: ) The oxygen atom of a metal alkoxide acts as a nucleophile to replace the halogen of an alkyl halide. The product is an ether. : : Hydrogen sulfide ion (HS: ) Use of hydrogen sulfide as a nucleophile permits the conversion of alkyl hal￾ides to compounds of the type RSH. These compounds are the sulfur ana￾logs of alcohols and are known as thiols. : : Azide ion (:N œN œN :) Sodium azide is a reagent used for carbon–nitro￾gen bond formation. The product is an alkyl azide. : : Carboxylate ion (RC±O: ) An ester is formed when the negatively charged oxygen of a carboxylate replaces the halogen of an alkyl halide. : : :O: X General equation and specific example Sodium isobutoxide (CH3)2CHCH2ONa Ethyl bromide CH3CH2Br Ethyl isobutyl ether (66%) (CH3)2CHCH2OCH2CH3 Sodium bromide NaBr isobutyl alcohol Potassium octadecanoate KOC(CH2)16CH3 O X Ethyl iodide CH3CH2I Ethyl octadecanoate (95%) CH3CH2OC(CH2)16CH3 O X Potassium iodide KI acetone water Pentyl iodide CH3(CH2)4I Sodium azide NaN3 Sodium iodide NaI Pentyl azide (52%) CH3(CH2)4N3 1-propanol￾water Ether ROR Halide ion X Alkoxide ion RO Alkyl halide R X Halide ion X Alkyl halide R X Carboxylate ion RCO O X Ester RCOR O X Halide ion X Alkyl halide R X Hydrogen sulfide ion HS Thiol RSH Potassium hydrogen sulfide KSH 2-Bromononane CH3CH(CH2)6CH3 Br W 2-Nonanethiol (74%) CH3CH(CH2)6CH3 SH W Potassium bromide KBr ethanol water Halide ion X Alkyl halide R X Cyanide ion NPC Alkyl cyanide RCPN Halide ion X Alkyl halide R X Alkyl azide RNœNœN Azide ion NœNœN Sodium cyanide NaCN Cl Cyclopentyl chloride CN Cyclopentyl cyanide (70%) Sodium chloride NaCl DMSO Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website