Lecture 15 Monday February 9 2015 1 52 PM As a base Reactions Organometallic reagents behave as carbanions They have electrons and they want to share them either with protons in that case we say they act as a base or with electrophiles in that case we say they are nucleophiles Organometallic reagents are strong bases because alkanes are very weak acids Carbanions really want to share electrons As a nucleophile For export Page 1 Lecture 15 Friday February 13 2015 11 17 AM As a nucleophile With carbonyls Retrosynthesis of alcohols formaldehyde aldehyde ketone Examples Primary alcohol Secondary alcohol Tertiary alcohol For export Page 2 Lecture 15 Friday February 13 2015 11 21 AM Reactions with derivatives of carboxylic acids with esters Carboxylic acid derivatives Notice that R and R have to be the same in this case the reaction does not work Overall reaction With alkyl halides Organocopper reagents Gilman reagent For export Page 3 Lecture 15 Friday February 13 2015 11 23 AM Synthesis Reactivity VS Reactions This transformation is not possible with RMgX or RLi Oxidative addition copper goes from 1 to 3 oxidation and R I adds to it Reductive elimination copper goes from 3 to 1 reduction and R R eliminates from it Scope and limitations Examples For export Page 4
View Full Document
Unlocking...