A variety of organocopper reactions including chlorotrimethylsilane-accelerated conjugate addition, regio- and diastereoselective SN2′-allylation reaction, and asymmetric carbocupration reaction are reviewed with emphasis on the results from author's own laboratories. 1. Introduction 2. Chlorosilane-Accelerated Conjugate Additions 2.1. Copper Homoenolate 2.2. Stoichiometric and Catalytic Copper Reagents 3. Chemoselectivity of Organocopper Reagents: A Zinc/Copper Combination 3.1. Metal Homoenolate Chemistry 3.2. Functionalized Copper Reagents 4. SN2′-Selective Allylation Reaction and its Diastereoselectivity 4.1. 1,2-Asymmetric Induction 4.2. A d-π* Model 5. A New Reaction: Asymmetric Carbocupration Reaction 5.1. Synthesis of Substituted Cyclopropenone Acetals 5.2. Carbocupration of Cyclopropenone Acetals 5.3. Asymmetric Carbocupration of Cyclopropenone Acetals