Question

Predict Reactivity of Organometallic Compounds For each set of compounds, predict which type of reaction is expected… Hint: the following reaction types can be considered: associative ligand substitution, dissociative ligand substitution, interchange ligand substitution, SN1cB substitution, oxidation addition, reductive elimination, 1,1-migratory insertion, 1,2 migratory insertion, beta-hydride elimination, alpha-hydride elimination, sigma-bond metathesis, pi-bond metathesis (olefin metathesis), cyclometallation, redox/electron transfer, photochemical excitation, quantum entanglement

a. [Ni(CO)4] + PPh3

b. [Rh(Cl)(PMe3)3] + H2

c. [Mn(CO)5(CH3)] + CO

d. [FeCp2]BF4 + [CoCp2]

e. [Ir(CO)(Cl)(I)(Me)(PPh3)2]

f. [Pd(PPh3)3] + allyl chloride

g. [Pd(Cl)(PPh3)2(CH2CH3)]

h. [Ru=CMe2(trans-Cl)2(trans-(PPh3)2] + α-methylstyrene

Answer 1

A) In this reaction, the nickel complex undergoes assosiative ligand substitution, to give mono and di substituted [Ni(CO)3(PPh3)] and [Ni(CO)2(PPh3)].

In this reaction, initially PPh3 gets attached with the complex and in next step carbonyl leaves the complex.

B)  [Rh(Cl)(PMe3)3] reacts with hydrogen to give oxidation addition reaction. Rhodium increases its oxidation state to give [Rh(Cl)(H2)(PMe3)3] , in this reaction both hydrogens are added in the same plane, both bond breaking and bond formation takes at the same time.

C) [Mn(CO)5(CH3)] undergoes migratory insertion reaction when reacted with CO. Initially , CO coordinates with the manganese complex, then CH3 migrates to CO to give Mn-(COCH3) bond formation. The final product of this reaction is [Mn(CO)5COCH3].

E) [Ir(CO)(Cl)(I)(Me)(PPh3)2] undergoes reductive elimination reaction. In this reaction Ir gets reduced giving MeI and [Ir(CO)(Cl)(PPh3)2].

F) This reaction is called Tsuji–Trost reaction. In this reaction the allylic group contains a leaving group. In this case the leaving group is Chlorine. The allylic group first undergoes oxidative addtion with Pd complex, then substitution reaction will take place with incoming nucleophile.

G) this Pd complex will undergo beta hydrogen elimination to give CH2=CH2 , and finally this hydrogen substitute this ethene in the complex.

D) This is simple oxidation reaction, Fe complex acts as one electron oxidising agent and oxidize Co to Co+

H) this reaction is oxidation addition reaction, which finally leads to formation of C-C bond and cause formation of polymer with multiple methylstyrenes.