Acyl chloride

An acyl chloride contains $\mathrm{R}-\mathrm{C}(\mathrm{O})\mathrm{Cl}$. Addition of a nucleophile and chloride elimination is a common substitution pathway.

$\mathrm{PhCOCl}$.

$\mathrm{C}{\mathrm{H}}_3\mathrm{COCl}$, an acylating reagent that converts an alcohol into an acetate ester when HCl is suitably removed.

The acyl chloride $(\mathrm{C}{\mathrm{H}}_3{)}_2\mathrm{CHCOCl}$, with equivalent methyl groups in an achiral environment.