Plants synthesize numerous ecologically specialized, lineage-specific metabolites through biosynthetic gene duplication and functional specialization. However, it remains unclear how duplicated genes are wired into existing regulatory networks. We show that the duplicated gene CYP82C2 has been recruited into the WRKY33 regulon and indole-3-carbonylnitrile (ICN) biosynthetic pathway through exaptation of a retroduplicated LINE retrotransposon ( EPCOT3 ) into an enhancer. The stepwise development of a chromatin-accessible WRKY33-binding site on EPCOT3 has potentiated the regulatory neofunctionalization of CYP82C2 and the evolution of inducible defense metabolite 4-hydroxy-ICN in Arabidopsis thaliana . Although transposable elements (TEs) have long been recognized to have the potential to rewire regulatory networks, these results establish a more complete understanding of how duplicated genes and TEs contribute in concert to chemical diversity and pathogen defense.
Novel scorpionate-type organocatalysts capable of effectively coupling carbon dioxide and epoxides under mild conditions to afford cyclic propylene carbonates were developed. On the basis of a combined experimental and computational study, a precise mechanistic proposal was developed and rational optimization strategies were identified. The epoxide ring-opening, which requires an iodide as a nucleophile, was enhanced by utilizing an immonium functionality that can form an ion pair with iodide, making the ring-opening process intramolecular. The CO activation and cyclic carbonate formation were catalyzed by the concerted action of two hydrogen bonds originating from two phenolic groups placed at the claw positions of the scorpionate scaffold. Electronic tuning of the hydrogen bond donors allowed to identify a new catalyst that can deliver >90% yield for a variety of epoxide substrates within 7 h at room temperature under a CO pressure of only 10 bar, and is highly recyclable.
A series of dimeric aluminum compounds [Al(OCMe2CH2N(R)CH2X)]2 [X=pyridin‐2‐yl, R=H (PyrH); X= pyridin‐2‐yl, R=Me (PyrMe); X=furan‐2‐yl, R=H (FurH); X= furan‐2‐yl, R=Me (FurMe); X=thiophen‐2‐yl, R=H (ThioH); X= thiophen‐2‐yl, R=Me (ThioMe)] containing heterocyclic pendant group attached to the nitrogen catalyze the coupling of CO2 with epoxides under ambient conditions. In a comparison of their catalytic activities with those of aluminum complexes without pendant groups at N [X=H, R=H (HH); X=H, R=Me (HMe)] or with non‐heterocyclic pendant groups [X=CH2CH2OMe, R=H (OMeH); X=CH2CH2NMe2, R=H (NMe2H); X=CH2CH2NMe2, R=Me (NMe2Me)], complexes containing heterocycles, in conjunction with (nBu)4NBr as a cocatalyst, show higher catalytic activities for the synthesis of cyclic carbonates under the same ambient conditions. The best catalyst system for this reaction is PyrH/(nBu)4NBr system, which gives a turnover number of 99 and a turnover frequency of 4.1 h−1, making it 14‐ and 20‐times more effective than HH/(nBu)4NBr and HMe/(nBu)4NBr, respectively. Although there are no direct interactions between the aluminum and the heteroatoms in the heterocyclic pendants, electronic effects combined with the increased local concentration of CO2 around the active centers influences the catalytic activity in the coupling of CO2 with epoxides. In addition, PyrH/(nBu)4NBr shows broad epoxide substrate scope and seven terminal epoxides and two internal epoxides undergo the designed reaction.
Long-term stability of the solid electrolyte interphase (SEI) and cathode–electrolyte interface (CEI) layers formed on anodes and cathodes is imperative to mitigate the interfacial degradation of electrodes and enhance the cycle life of lithium-ion batteries (LIBs). However, the SEI on the anode and CEI on the cathode are vulnerable to the reactive species of PF5 and HF produced by the decomposition and hydrolysis of the conventional LiPF6 electrolyte in a battery inevitably containing a trace amount of water. Here, we report a new class of cyclic carbonate-based electrolyte additives to preserve the integrity of SEI and CEI in LIBs. This new class of additives is designed and synthesized by an ecofriendly approach that involves fixing CO2 with functional epoxides bearing various reactive side chains. It was found that the cyclic carbonates of 3-(1-ethoxyethoxy)-1,2-propylene carbonate and 3-trimethoxysilylpropyloxy-1,2-propylene carbonate, possessing high capability for the stabilization of Lewis-acidic PF5, exhibit a capacity retention of 79.0% after 1000 cycles, which is superior to that of the pristine electrolyte of 54.7%. Moreover, TMSPC has HF-scavenging capability, which, along with PF5 stabilization, results in enhanced rate capability of commercial LiNi0.6Mn0.2Co0.2O2 (NCM622)/graphite full cells, posing a significant potential for high-energy-density LIBs with long cycle stability.
First structurally characterized dimeric alumatranes with tricyclic five-membered rings were determined by single-crystal X-ray analysis and DFT calculations. New alumatranes were used as catalysts for trimethylsilycyanation reaction of aldehydes.
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