1.C-C bond formation 用里 tohols can be formed from epoxides, aldehydes,ketones,esters,and acid chlorides as a consequence of C-C bond formation with Grignard or organolithium reagents OH -OCH2CH3 2CH3MgBr H3O CH; CH3 ether
1. C-C bond formation ◼Alcohols can be formed from epoxides, aldehydes, ketones, esters, and acid chlorides as a consequence of C-C bond formation with Grignard or organolithium reagents C O OCH2CH3 CH3MgBr ether C OH CH3 CH3 2 H3O +
Organometallic Reagents Carbon is bonded to a metal (Mg or Carbon is nucleophilic (partially negative). It will attack a partially positive carbon. C-X C=0 A new carbon-carbon bond forms
Organometallic Reagents ❖Carbon is bonded to a metal (Mg or Li). ❖Carbon is nucleophilic (partially negative). ❖It will attack a partially positive carbon. ◼C - X ◼C = O ❖A new carbon-carbon bond forms
Grignard Reagents Formula R-Mg-X (reacts like R:+MgX) Stabilized by anhydrous ether Iodides most reactive May be formed from any halide -Primary,secondary,tertiary,vinyl,aryl Limitations of Grignard -No water or other acidic protons like O-H,N-H,S-H,or-C-C-H.Grignard reagent is destroyed,becomes an alkane. No other electrophilic multiple bonds,like C=N,C=N, S=0,orN=0
Grignard Reagents ❖Formula R-Mg-X (reacts like R:- +MgX) ❖Stabilized by anhydrous ether ❖Iodides most reactive ❖May be formed from any halide ◼Primary, secondary, tertiary, vinyl, aryl ❖Limitations of Grignard ◼No water or other acidic protons like O-H, N-H, S-H, or -C—C-H. Grignard reagent is destroyed, becomes an alkane. ◼No other electrophilic multiple bonds, like C=N, CN, S=O, or N=O
Some Grignard Reagents Br ether MgBr Mg CI MgCI CH3CHCH2CH3 ether Mg CH3CHCH2CH3 CH3C=CH2 Br Mg ether CH3C=CH2 MgBr
Some Grignard Reagents Br + Mg ether MgBr CH3CHCH2CH3 Cl ether + Mg CH3CHCH2CH3 MgCl CH3C CH2 Br + Mg ether CH3C CH2 MgBr
Organolithium Reagents Formula R-Li (reacts like R:+Li) Can be produced from alkyl,vinyl,or aryl halides,just like Grignard reagents. Ether not necessary,wide variety of solvents can be used
Organolithium Reagents ❖Formula R-Li (reacts like R:- +Li) ❖Can be produced from alkyl, vinyl, or aryl halides, just like Grignard reagents. ❖Ether not necessary, wide variety of solvents can be used