Copper‐Catalyzed Enantioselective Conjugate Addition of Dialkylzinc Reagents to α′‐Oxy Enones

Abstract

The utilization of oxygen vacancies (OVs) in sodium ion batteries (SIBs) is expected to enhance performance, but as yet it has rarely been reported. Taking the MoO3−x nanosheet anode as an example, for the first time we demonstrate the benefits of OVs on SIB performance. Moreover, the benefits at deep‐discharge conditions can be further promoted by an ultrathin Al2O3 coating. A series of measurements show that the OVs increase the electric conductivity and Na‐ion diffusion coefficient, and the promotion from ultrathin coating lies in the effective reduction of cycling‐induced solid‐electrolyte interphase. The coated nanosheets exhibited high reversible capacity and great rate capability with the capacities of 283.9 (50 mA g−1) and 179.3 mAh g−1 (1 A g−1) after 100 cycles. This work may not only arouse future attention on OVs for sodium energy storage, but also open up new possibilities for designing strategies to utilize defects in other energy storage systems.

Enantioselective Copper‐Catalyzed Conjugate Addition of Trimethylaluminium to β,γ‐Unsaturated α‐Ketoesters

“…To complement our previous work with a,b-unsaturated aldehydes, [19] we decided to apply a simple derivatization procedure to obtain the corresponding chiral b-substituted aldehyde. The groups of Feringa, [24] Hoveyda, [25] Palomo, [26] and Mazet [27] have already developed alternative methodologies to obtain this type of product but the yield, regio-and/or enantioselectivity left room for improvement. A two-step, reduction/ oxidation [28] procedure was applied to the synthesis of (S)-florhydral.…”

Alkylation of Electron‐Deficient Olefins through Conjugate Addition of Organozinc Reagents: An Update

“…Dialkylzinc was reacted with α'-oxy enones in the presence of Cu(OTf) 2 along with a asymmetric catalyst in toluene or DCM at 0 °C (Scheme 19). [34] The asymmetric ligand used in the reaction was alanine-derived aminohydroxyphosphine, which was developed by Nakamura et al (Scheme 17). The reaction gave high yield with excellent enantioselectivity of desired products.…”

(±)-trans-1,2-Cyclohexanediamine-Based Bis(NHC) Ligand for Cu-Catalyzed Asymmetric Conjugate Addition Reaction

“…In contrast to the conjugate addition reactions of organometallic compounds with cyclic enones, few highly enantioselective reactions of acyclic enones have been reported [71,[82][83][84][85][86][87][88][89][90][91][92][93]. We then focused on studying the Cu-catalyzed asymmetric 1,4-addition reaction of acyclic enone with Et 2 Zn using this promising class of bis(NHC) chiral ligand L1.…”