Question

The reaction involve(s)

• A. migratory insertion
• B. change in electron count of Rh from 18 to 16
• C. oxidative addition
• D. change in electron count of Rh from 16 to 18

Answer 1

The Correct Option is A, B

The question involves analyzing the reaction and determining which processes are involved. Let's break down the reaction step-by-step:

1. Observing the reaction diagram, we notice that the substrate undergoes a change where the alkene migrates to a different position within the complex. This is characteristic of a migratory insertion reaction. During migratory insertion, a migrating group (such as an alkyl or aryl group) and a vacant coordination site move from adjacent positions into a single position on the metal's coordination sphere.
2. For electron counting, initially, the Rhodium (Rh) complex has an 18-electron configuration, considering all ligands and electrons around Rh. Migratory insertion typically results in the reduction of the electron count, as seen in this process where Rh transitions from an 18-electron to a 16-electron count.
3. Now, let's evaluate the given options:
   • Migratory insertion: Correct. As described, it involves the rearrangement and insertion of the migrating group.
   • Change in electron count of Rh from 18 to 16: Correct. The electron count decreases in the process.
   • Oxidative addition: Incorrect. Oxidative addition is not observed here, as it typically involves an increase in the metal’s oxidation state and electron count, which does not occur.
   • Change in electron count of Rh from 16 to 18: Incorrect. The reaction involves a decrease, not an increase, in electron count.

In conclusion, the processes involved are migratory insertion and a change in electron count from 18 to 16.