Selectivity is an important feature in organic reactions. The three most common are chemoselectivity, regioselectivity and stereoselectivity. Chemoselective reactions are those with a preference for one of two or more possible reactive entities (eg same functional groups). Scheme 2. Chemoselective reduction of 4-nitroacetophenone (Experimental Organic Chemistry, Laboratory Manual, 2016, Pages 239-289)