The first broadly applicable strategy for S(N)2 ''-selective and enantioselective catalytic substitution is disclosed. Transformations are promoted by 5.0 mol% of a sulfonate-containing NHC-Cu complex (NHC = N-heterocyclic carbene), and are carried out in the presence of commercially available allenyl-B(pin) (pin = pinacolato) or a readily accessible silyl-protected propargyl-B(pin). Acyclic, or aryl-, heteroaryl-, and alkyl-substituted penta-2,4-dienyl phosphates, as well as those bearing either only 1,2-disubstituted olefins or a 1, 2-disubstituted and a trisubstituted alkene were found to be suitable starting materials. Cyclic dienyl phosphates may also serve as substrates. The products containing, in addition to a 1,3-dienyl group, a readily functionalizable propargyl moiety (from reactions with allenyl-B(pin)) were obtained in 51-82% yield, 84-97% S-N(2)" selectivity, 89:11-97:3 E:Z ratio, and 86:14-98:2 enantiomeric ratio (er). Reactions with a silyl-protected propargyl-B(pin) compound led to the formation of the corresponding silyl-allenyl products in 53-89% yield, 69-96% S(N)2 '' selectivity, 98:2 to >98:2 E:Z ratio, and 94:6-98:2 er. Insight regarding several of the unique mechanistic attributes of the catalytic process was obtained on the basis of kinetic isotope effect measurements and DFT studies. These investigations indicate that cationic pi-allyl-Cu complexes are likely intermediates, clarifying the role of the s-cis and s-trans conformers of the intermediate organocopper species and their impact on E:Z selectivity and enantioselectivity. The utility of the approach is demonstrated by chemoselective functionalization of various product types, through which the propargyl, allenyl, or 1,3-dienyl sites within the products have been converted catalytically and chemoselectively to several useful derivatives.