270 likes | 497 Vues
Chapter 15. Organometallic Compounds (R-M). Organomagnesium & Organolithium compds 15.1. Lithium Diorganocopper (Gilman) Reagents 15.2. No t covered: Organopalladium reagents, Heck reaction, carbenes, carbenoids, & alkene metathesis. Synthesis, Concepts and the Final. covalent and
E N D
Chapter 15 OrganometallicCompounds(R-M) Organomagnesium & Organolithium compds 15.1 Lithium Diorganocopper (Gilman) Reagents 15.2 Not covered: Organopalladium reagents, Heck reaction, carbenes, carbenoids, & alkene metathesis. Synthesis, Concepts and the Final
covalent and ionic view free radical like Prep of Organometallic Compounds Grignard (organomagnesium compound)
Alkyllithium OR Prep of Organometallic Compounds Grignard
How does one make the anion of butane? Use - base(E2) or Nu: (SN2)
Prep of R-M (Nu:- +M) alkyl halide (sp3) + metal But also: vinyl halide (sp2) + metal aryl halide (sp2) + metal e.g. Grignard or organomagnesium reagent
Lithium Diorganocopper Reagents Prep and use in Synthesis (similar Grignard reagent can be made)
Use: substitution rx, replace halides Organometallics, alkyllithiums can be nucleophiles….. Chapter 7 and 9 Or as anion
Use: substitution rx, replace halides Grignards and alkyllithiums can be nucleophiles….. butcuprates are better
add eliminate* add eliminate* Use: Substitution, replace leaving group *not really SN2, ignore mechanism, 2nd semester
Rxs substitution in chapter 11 Primary site inverted, secondary unchanged.
Better Organometallic Compounds 15 earlier = RMgX or RLi
Nucleophilic Rxs - important for 2nd semester carbonyl addition same product different connection
DMF NBS hv target SM +
SYNTHESIS Propose how to convert starting material (sm) to a target rules: Use any number of steps For each step show: - necessary reagents - necessary conditions - expected product or products SM target
SYNTHESIS Compare functional groups and carbon skeleton starting material target Need: 1 carbon (CN) and ketone + nitrile from olefin
NC-/DMF PCC Br2 H2Oxs SYNTHESIS retroanalysis SM target
RCO3H PCC NC-/DMF PCC DMSO H2O SYNTHESIS retroanalysis Br2 H2Oxs SM target
“thoughts” --- join--- synthesis How?
reverse? synthesis synthesis How? How? plan
PBr3 Mg/THF RCO3H H+/H2O