Asymmetric catalysis has been considered to be the most intriguing means for building collections of functionalized optically active compounds. In particular, metal and organocatalysis have been well established to allow many fundamentally different reactions. Metal catalysis has enabled the participation of a much broader scope of chemical bonds in organic transformations than are allowed by organocatalysis, while organocatalysis permits a broader scope of functional groups to undergo a diverse range of enantioselective transformations, individually, simultaneously, or sequentially. Theoretically, the combination of organocatalysts and metal complexes could probably render new transformations through the simultaneous or sequential activation and reorganization of multiple chemical bonds if the superior features of both the catalysts are adopted. In 2001, both our research group and Takemoto's group separately described an asymmetric allylation of glycine imino esters with allyl acetate catalyzed by palladium complexes and chiral ammonium salts. In these cases, the oxidative addition of palladium complexes to allyl acetate formed the π-allylic fragments, while the chiral ammonium salts were actually responsible for controlling the stereoselectivity. These reactions in fact marked the beginning of asymmetric organo/metal combined catalysis. Since then, asymmetric organocatalysis combined with metal catalysis, including cooperative catalysis, relay catalysis, and sequential catalysis, has been a versatile concept for the creation of unknown organic transformations. Sequential catalysis describes a one-pot reaction involving two or more incompatible catalytic cycles. Alternatively, cooperative and relay catalyses require high compatibility of principally distinct catalysts and will be the focus of this Account. The catalysts in cooperative catalytic reactions must be able to simultaneously and individually activate both substrates to drive a bond-forming reaction, while relay catalysis is basically defined as a cascade process in which two or more sequential bond-forming transformations are independently catalyzed by distinct catalysts. In the past decade, we have discovered a variety of binary catalytic systems consisting of metals, including Rh(II), Pd(0), Au(I), and Mg(II), and chiral organocatalysts, including chiral phosphoric acids and quinine-based bifunctional molecules, for cooperative catalysis and relay catalysis, allowing the accomplishment of many unprecedented asymmetric transformations. In this Account, these achievements will be summarized, particularly focusing on the description of the concept and proof of the concept, to demonstrate the robustness of combined organo/metal catalysis in the creation of efficient enantioselective transformations. In addition, elegant studies from other laboratories using chiral phosphoric acid/Au(I) for the establishment of asymmetric cascade reactions involving the carbon-carbon triple bond functionality and typical combined organo/metal catalytic systems, very rece...

A functional group tolerant cobalt-catalyzed method for the intermolecular hydrofunctionalization of alkenes with oxygen- and nitrogen-based nucleophiles is reported. This protocol features a strategic use of hypervalent iodine­(III) reagents that enables a mechanistic shift from conventional cobalt–hydride catalysis. Key evidence was found supporting a unique bimetallic-mediated rate-limiting step involving two distinct cobalt­(III) species, from which a new carbon–heteroatom bond is formed.

Novel, highly asymmetric zinc phthalocyanine (ZnPc) derivatives (Zn‐tri‐PcNc) containing tribenzonaphtho‐condensed porphyrazine with one carboxyl and three tert‐butyl (tBu) or n‐butoxy (nBuO) peripheral substituents were synthesized by using 6‐carboxymethyl‐2,3‐dicyanonaphthalene and 4‐tBu‐ or nBuO‐phthalonitrile as starting agents. The new, highly asymmetric ZnPc containing tBu groups (Zn‐tri‐PcNc‐2 b) yielded a 3.56 % conversion efficiency in sensitizing TiO2‐based dye‐sensitized solar cells (DSSCs) under simulated AM 1.5G solar irradiation (100 mW cm−2), which is higher than that of the nBuO‐containing analogue Zn‐tri‐PcNc‐3 b (2.20 %). Moreover, Zn‐tri‐PcNc‐2 b displays 60.7 % of the maximum incident monochromatic photon‐to‐current conversion efficiency (IPCE) in the red/near‐IR region, which is much higher than that of Zn‐tri‐PcNc‐3 b (22.9 %), thus highlighting the potential of Zn‐tri‐PcNc‐2 b as a DSSC component.