Nucleophilic addition of organochromium reagents to carbonyl compounds

One important theme in organic synthesis is to accomplish highly selective transformations under mild conditions, which yield only desirable products. During the past two decades, we have developed several useful tools to ach ieve this, i.e., organochromium reagents. This review focuses on the follow ing themes: 1) The historical background of organochromium reagents. 2) The development of the allylic chromium reagent (Nozaki-Hiyama reaction). 3) N ickel-catalyzed addition of alkenyl-, aryl-, and alkynyl halides to aldehyd es (Nozaki-Hiyama-Kishi (NHK) reaction). 4) Wittig-type olefination with ge minal dichromium reagents. 5) Representative applications of organochromium reagents to the total syntheses of biologically active compounds.