Question

Reductive amination of aldehydes and ketones is a versatile method for attaching alkyl groups to amines, but the alkyl group is restricted to a 1 ⁰or 2⁰carbon by this method. Prof. Phil Baran of Scripps Research Institute has reported (Science, 2015, 348(6237), 886-891) a novel way to reduce an aromatic nitro group and add the resulting amine to an alkene so that the aromatic amine is bonded to a carbon- all in a continuous sequence of reactions. For example:

Predict the products using these starting materials, all of which are reported in this paper.

Short answer

New bonds are shown in bold

Step-by-step solution

Step-1. Explanation of part (a): 

The aromatic nitro group gets reduced to amino group in the presence of iron(III) catalyst and phenylsilane, ethanol. It is a novel way to reduce an aromatic nitro group and add the resulting amine to an alkene so that the aromatic amine is bonded to a carbon- all in a continuous sequence of reactions. The new bond forms which is attached to the ring containing alkene group.

Product formation using iron(III) catalyst, phenylsilane and ethanol

Step-2. Explanation of part (b)

The aromatic nitro group gets reduced to amino group in the presence of iron(III) catalyst and phenylsilane, ethanol. It is a novel way to reduce an aromatic nitro group and add the resulting amine to an alkene so that the aromatic amine is bonded to a carbon- all in a continuous sequence of reactions. The new bond forms which is attached to the ring containing alkene group

Product formation using iron(III) catalyst, phenylsilane and ethanol

Step-3. Explanation of part (c):

The aromatic nitro group gets reduced to amino group in the presence of iron(III) catalyst and phenylsilane, ethanol. It is a novel way to reduce an aromatic nitro group and add the resulting amine to an alkene so that the aromatic amine is bonded to a 3 ⁰carbon- all in a continuous sequence of reactions. The new bond forms which is attached to the ring containing alkene group.

Step-4. Expalantion of part (d);

Product formation using iron(III) catalyst, phenylsilane and ethanol