Organocuprate and Organozinc Reagents Part1

Question 1

The relative reactivity of organometallic compounds as nucleophiles and bases largely mirror the degree of _________ of M-C bond

Answer 1

Polarisation

Question 2

The more ________ the metal ion, the more ionic the bonding between the metal and organic fragment is and, in general, the more _____ and ________ the reagent is.

Answer 2

electropositive, basic, nucleophilic

Question 3

Zinc and copper are more/less electropositive than lithium or magnesium.

Answer 3

less

Question 4

What is the difference between Gilman Cuprates, Normant Cuprates and Knochel Cuprates?

Answer 4

The metal cations are different. In Gilman the metal cation is Li, in Normant MgX and in Knochel, ZnI.

Question 5

What is a drawback of classical Gilman or Normant cuprates?

Answer 5

One equivalent organic group is sacrificed in the reaction, meaning that you need 2 equivalent organic groups when only 1 organic group will be transferred to the product compound.

Question 6

Order the following compounds according to its reactivity with organocuprate reagents: Aldehyde, Alkyl Halide, Acid Chloride, Epoxide, Ketone, Ester, alpha, beta- unsaturated carbonyl

Answer 6

Acid chloride > Aldehyde > Alkyl Halide ~= Epoxide ~= alpha,beta-unsaturated cabonyl&raquo_space;> Ketone, Ester

Question 7

In comparison to Grignard reagents and organolithium reagents, organucuprates are much more efficient as nucleophiles in __________ reactions of alkyl electrophiles.

Answer 7

Substitution