# Hydrosilylation of Esters via a Titanocene(III) Borohydride–PMHS System: Scope, Limitations, and Mechanistic Insights

## TL;DR

A new method for converting esters into alcohols using a titanocene catalyst and a silane reductant is described, offering mild and cost-effective conditions.

## Contribution

A novel hydrosilylation method for ester reduction using titanocene(III) borohydride and PMHS is introduced.

## Key findings

- Alcohol yields range from 43% to 99% using catalytic amounts of titanocene(III) borohydride and PMHS.
- Isopropanol addition enhances reactivity by forming a more active titanocene(III) hydride species.
- The method is mild, cost-effective, and applicable to a wide range of esters.

## Abstract

The hydrosilylation of aromatic and aliphatic esters
using catalytic
amounts of titanocene­(III) borohydride and poly­(methylhydrosiloxane)
(PMHS) as the terminal reductant is described. Alcohol yields range
from 43% to 99%, with select esters requiring the addition of isopropanol
to promote reactivity. This modification is proposed to facilitate
in situ formation of a more reactive titanocene­(III) hydride species,
which appears necessary for efficient ester reduction. This ester
reduction protocol is mild, cost-effective, operationally simple and
has potential utility in broader reductive transformations.