Introduction
The title compound (HBTU, 1) is a useful
condensing agent, which has become in the past decade one of the most
popular coupling reagents for in situ activation of peptide synthesis
both in solid phase and in solution.
[¹-5]
The
same benzotriazolyl derivative has also been successfully employed
for esterifications, as for example in solid-phase nucleotide synthesis.
[6]
[7]
In
addition to its high reactivity, HBTU has also been shown to fulfill
the very important requirement of minimizing racemization at adjacent
sites. Sometimes, hydroxybenzotriazole (HOBt) is used together with
HBTU as racemization suppressor. Thus, HBTU effectively performs
condensation with high yields and minimal racemization, in simple
experimental conditions and within short reaction times.
Figure 1
