# Protective Group-Dependent Iridium-Catalyzed CH Borylations of Levodopa

## TL;DR

This paper reports a new method to selectively borylate levodopa using iridium catalysts by managing steric hindrance with protecting groups.

## Contribution

The study introduces a protective group strategy enabling selective C5 CH borylation of levodopa with iridium catalysts.

## Key findings

- Selective C5 CH borylation of levodopa is achieved using boronic ester protecting groups.
- In situ deprotection of the boronic ester group yields the free catechol.
- Protecting groups reduce steric hindrance, enabling iridium-catalyzed borylation.

## Abstract

Despite being an important aromatic amino acid, iridium-catalyzed
borylation (CHB) of levodopa has not been reported. Via the application
of carefully chosen protecting groups for the catechol moiety, the
steric hindrance around the arene can be reduced, enabling selective
C5 CHB of levodopa. Methylene and boronic ester protecting groups
were explored, the latter of which is deprotected in situ to yield
the free catechol.