# Wrap cells of tabular in macro

I would like to use the column specification syntax of memoir's tabular environment to automatically wrap cells of a table in a macro. Is that possible? I tried the following

\documentclass{memoir}
\newcommand\bracketit[1]{[#1]}
\begin{document}
\begin{tabular}{l>{\bracketit\bgroup}c<{\egroup}}
1 & A \\
2 & B \\
\end{tabular}
\end{document}


which fails with

! Missing } inserted


I had hoped it would be equivalent to

\documentclass{memoir}
\newcommand\bracketit[1]{[#1]}
\begin{document}
\begin{tabular}{lc}
1 & \bracketit{A} \\
2 & \bracketit{B} \\
\end{tabular}
\end{document}


but without the typing. Of course, with the simple \bracketit, there is no need for a macro, I could insert the brackets directly. However, the macro that I want to apply is not that simple and out of my hands (mhchem.sty's \ce). Is what I try to do possible at all?

This is possible with the collcell package:
\documentclass{memoir}