cinnamonitriles_cinnamonitrile(4)

9.3.CarbonylationofOrganicHalides

9.3.1.CarbonylationofAlkylHalides

Transition-metal-catalyzedcarbonylationof1-per-fluoroalkyl-substituted2-iodoalkaneshasbeencar-riedoutinaqueousmediatogivecarboxylicacidswithaperfluoroalkylsubstituentatthe??position(eq172).648Thecarbonylationofrepresentativealkyl,

allyl,benzyl,aryl,andvinylhalidescatalyzedbycomplexesofgroupVIIImetalsproceededinthepresenceofwateroralcoholsinN,N,N′,N′-tetraalkyl-ureaintheabsenceofanaddedbasetogivethecorrespondingcarboxylicacidsoresters,respectively,ingoodtoexcellentyields.649

9.3.2.CarbonylationofAllylicandBenzylicHalides

Thetransition-metal-catalyzedcarbonylationofallylicandbenzyliccompoundsoffersausefulmethodforthesynthesisof??,γ-unsaturatedacids.650Therequirementofhighcarbonmonoxidepressureandthelowyieldoftheproductslimitedtheusefulnessofthemethodinorganicsynthesis.651In1977,itwasfoundthatthecarbonylationofbenzylbromideandchloridecouldbecarriedoutbystirringaqueoussodiumhydroxideandanorganicsolventusinga

Li

phase-transferagenttogetherwithacobaltcatalyst(eq173).652,653Underhighpressureandtemperature,

evenbenzylicmercaptansreactedsimilarlytogiveesters.654Inthepresenceofanickelcatalyst,similarcarbonylationsofallylbromideandchlorideinaque-ousNaOHcanbecarriedoutatatmosphericpres-sure.655Thebaseconcentrationsignificantlyinflu-encedtheyieldandtheproductdistribution.Morerecently,itwasfoundthatthepalladium-catalyzedcarbonylationofallylchlorideproceededsmoothlyinatwo-phaseaqueousNaOH/benzenemediumunderatmosphericpressureatroomtemperature.656Cata-lystswithorwithoutphosphorusligandsgavesimilarresultsandthepresenceofhydroxidewasessential.Thereactionseemedtooccurattheliquid-liquidintecebecausenophase-transferagentwasused.However,theadditionofsuctantssuchasn-C7H15-SO3Naorn-C7H15CO2Nadoesacceleratethereac-tions.657

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