One of the most useful chemical properties of "n"-BuLi is its ability to deprotonate a wide range of weak Brønsted acids. "t"-Butyllithium and "s"-butyllithium are more basic. "n"-BuLi can deprotonate (that is, metalate) many types of C-H bonds, especially where the conjugate base is stabilized by electron delocalization or one or more heteroatoms (non carbon atoms). Examples include acetylenes ("H"-CC-R), methyl sulfides ("H"-CH2SR), thioacetals ("H"-CH(SR)2, e.g. dithiane), methylphosphines ("H"-CH2PR2), furans, thiophenes and ferrocene (Fe("H"-C5H4)(C5H5)). In addition to these, it will also deprotonate all more acidic compounds such as alcohols, amines, enolizable carbonyl compounds, and any overtly acidic compounds, to produce alkoxides, amides, enolates and other -ates of lithium, respectively. The stability and volatility of the butane resulting from such deprotonation reactions is convenient, but can also be a problem for large-scale reactions because of the volume of a flammable gas produced.