Reactions between organometallic nucleophiles and C-based electrophiles

turn alkynes into alkanes

H2, Pd (cat)

turns alkynes into cis alkenes

H2, Lindlar’s catalyst (Pd/BaSO4)

turns alkynes into trans alkenes

K, NH3 or Na,NH3 (dissolving metal reduction)

turns alkynes into ketones

HgSO4, H2O, H2SO4 

turnes alkynes into aldehydes

1. (Sia)2BH, THF 2. H2O2, OH-, H20

turns alkynes into geminal dihalides

HBr (2 eq.) or HCl (2 eq.)

turns alkynes into vicinal dihalides

1. H2, Lindlar’s cat 2. Br2, CHCl2

turns ketones into secondary alcohols

 NaBH4, EtOH

turns Aldehyde/Acid chlorides into primary alcohols

NaBH4

turns acid chlorides into aldehydes

 Li(tBuo)3AlH

turns acid chlorides into ketones

-CuLi-

synthesis of lithium dialkyl cuprates (Gilman’s reagent)

1. Br2, hv

2. Li

3. CuI (0.5 eq.)

turn acetylide ion into internal alkynes

1. NaNH2, NH3 (1)

2. primary alkyl halide

turn acetylide ion into alcohol where OH group is attached to C atom directly bonded to triple bonded C atom

1. NaNH2, NH3 (1)

2. ketone/aldehyde

3. H3O+ (dilute) H2O

turn acetylide ion into alcohol where the OH group is two C atoms removed from the triple bonded C

1. NaNH2, NH3 (1)

2. epoxide

3. H3O+ (dilute), H2O

turn acetylide ion into a tertiary alcohol (unreliable/uncommon)

1. NaNH2, NH3 (1)

2. ester/acid chloride

3. H3O+ (dilute), H2O

turn aldehyde/ketone into alcohol where the OH is attached to the C atoms in the new C-C bond

1. -MgBr

2. H3O+ (dilute), H2O

turn epoxides into alcohols where the OH group is adjacent to the new C-C bond

1. —Li or —MgBr

2. H3O+ (dilute), H2O

turn ester/acid chloride into a tertiary alcohol through an addition/elimination mechanism

1. —MgBr (2 eq.) or —Li (2 eq.)

2. H3O+ (dilute), H2O

substitute LG of vinyl halides/alkyl halide with new C— bond

—Cu— (-), Li (+), THF

Gilman reagents (lithium dialkyl cuprates) are typically not reactive toward…

aldehydes and ketones

turn epoxides into alcohols where the OH group is 2 C atoms removed from the new C-C bond

1. —CuLi—

2. H3O+ (dilute), H2O

turn acid chlorides (but not esters) into ketones (which do not react further)

-CuLi-, Et2O

cleaves alkyne creating one OH group and one =O group

KMnO4, H3O+, heat. or 1. O3, 78 degrees C 2. H20

cleaves alkyne creating two =O groups

KMnO4, pH=7, 5 degrees C