# Room-Temperature Metal-Catalyzed Hydrogen Borrowing Alkylation

## TL;DR

This paper reviews recent advances in room-temperature hydrogen borrowing reactions, which use alcohols to form carbon-carbon and carbon-nitrogen bonds efficiently.

## Contribution

The paper provides a comprehensive overview of room-temperature hydrogen borrowing reactions, highlighting recent developments and current limitations.

## Key findings

- Room-temperature hydrogen borrowing reactions are feasible for carbon-carbon and carbon-nitrogen bond formation.
- These reactions offer advantages such as using stable alcohol substrates and generating water as the only byproduct.
- Most prior reactions required high temperatures, but recent work has enabled milder conditions.

## Abstract

Hydrogen borrowing
describes a one-pot multistep sequence
in which
an alcohol is used as an alkylating agent. In comparison to a traditional
alkylation reaction using alkyl halides, this is an attractive strategy:
alcohol substrates are commercially abundant and stable, the process
uses catalytic amounts of metal and base, and water is generated as
the sole byproduct. Since seminal reports in the early 2000s, the
field has been investigated extensively, but most hydrogen borrowing
reactions operate under a high-temperature regime (76–200 °C),
particularly those involving carbon–carbon bond formation.
This review provides an overview of the current state of the art in
room-temperature (≤30 °C) hydrogen borrowing reactions,
including both carbon–carbon and carbon–nitrogen bond
formation.