A polarized Au(I)/Pt(0) complex with only two phosphines unlocks cooperative reactivity that is inaccessible for previous Au/Pt saturated systems. Selective CX activation of halopyridines occurs via Pt-centered oxidative addition, while CH activation of pyridine-N-oxide involves a synergistic bimetallic pathway leading to a unique carbene structure.

Bulky terphenyl phosphine ligands allow the isolation of a masked low-coordinate, highly polarized Au(I)/Pt(0) complex. At variance to the inertness of prior coordinatively saturated AuPt systems, this complex exhibits cooperative reactivity toward pyridines. CX activation is observed for 2-halopyridines (X = I, Br, Cl), while selective ortho-CH activation of pyridine-N-oxide yields an unexpected pyridylidene carbene structure. Computational studies support the synergistic effect of the two metals during bond activation and shed light on the electronic structure of some of these unique species.

The pyridoxal 5′-phosphate dependent decarboxylative aldolase, UstD was engineered to catalyze a Mannich reaction with cyclic imines. This enzymatic route was applied to synthesize 23 enantioenriched noncanonical amino acids with benzosultam side chains, achieving yields up to 96%, a total turnover number (TTN) of 7500, and excellent stereoselectivity (>95:5 d.r., >99:1 e.r.).

Functionalized benzosultam and sulfonamide derivatives represent privileged pharmacophores in medicinal chemistry. However, noncanonical amino acids (ncAAs) featuring benzosultam side chains remain underexplored for peptide therapeutics, despite significant advances in peptide drug development. Herein, we report the promiscuous activity of the PLP-dependent decarboxylative aldolase UstD in catalyzing β-Mannich reactions. An engineered variant, UstD2.0S60A, was developed and applied to synthesize 23 enantioenriched ncAAs, achieving yields up to 96%, a total turnover number (TTN) of 7500, and excellent stereoselectivity (>95:5 dr, >99:1 er). The reaction is scalable to gram quantities for preparative applications. This study facilitates the future use of benzosultam-containing ncAAs in peptide chemistry and highlights the opportunity of engineering aldolases for non-natural Mannich reaction to access chiral amine products.

Flow-pulse adsorption microcalorimetry is established as a general method for characterizing diffusion processes on solid catalysts, a key elementary step capable of regulating their catalytic performances.

Fundamental studies of diffusion processes on solid catalysts are challenging due to the lack of appropriate characterization techniques. Herein, using NH3 diffusion on various zeolites as an example, flow-pulse adsorption microcalorimetry (FPAM) is demonstrated capable of characterizing diffusion processes on solid catalysts. Initial adsorption heats and differential adsorption heats of NH3 on zeolites are measured temperature-dependent arising from the diffusion of adsorbed NH3 from the weakly adsorbed Lewis acidic sites (LAS) to the strongly adsorbed Brønsted acid sites (BAS). A model is then established to acquire the temperature-dependent distributions of NH3 adsorbed at the LAS and BAS sites, from which the LAS-to-BAS diffusion barrier of adsorbed NH3 is derived between 3.1 and 7.4 kJ mol−1 mainly related to the binding energy of NH3 adsorbed at the LAS. The applicability of FPAM method is further demonstrated by determing the weak adsorption site-to-strong adsorption site diffusion barriers of adsorbed NH3 on silicalite-1 and adsorbed C3H6 on MOR-10 as 7.3 and 17.9 kJ mol−1, respectively. The established FPAM method is a general method and will greatly enable the studies of diffusion processes on solid catalysts, a key elementary step capable of regulating their catalytic performances.

Enantiopure helicene-bis-porphyrin conjugates displaying exciton coupling chirality and spin polarization through chiral-induced spin selectivity have been prepared and studied both experimentally and theoretically.

Following previous work on helicene–porphyrin conjugates in which carbo[6]helicene are connected to zinc-porphyrin via phenyl-bis-ethynyl bridges (Por(Zn)-H[6] 1 , series 1), and displaying clear exciton coupling (EC) chirality, novel carbo[6]helicenes derivatives substituted at their 2,15 positions by zinc-porphyrin units are prepared, either through a triple bond (Por(Zn)-H[6] 2 , series 2), or through an alkynyl-phenyl bridge (Por(Zn)-H[6] 3 , series 3). Series 2 is also synthesized with free porphyrins or different metals [Ni(II) and Pd(II)]. Their photophysical and chiroptical properties (electronic circular dichroism and circularly polarized luminescence) are characterized, and it is examined how i) the distance between the porphyrin units and ii) the metal type impacted these properties. Experimental and theoretical analyses highlight strong responses originating from EC chirality in combination with the typical helicene-centered optical activity. The Por(Zn)-H[6] 2 system displaying strong absorption dissymmetry factors is then selected to experimentally examine the chiral-induced spin selectivity effect by magnetic conductive atomic force microscopy; a spin polarization of 50% is measured.

This review explores the evolution of bioinspired light-driven rotary molecular systems (RMSs), highlighting the integration of natural chromophore-based fragments to enhance quantum efficiency, photostability, and biocompatibility. Key strategies to optimize photochemical performance and broaden functional applications are discussed, providing a forward-looking perspective on the design and potential of next-generation RMSs.

To harness the potential of rotary molecular systems (RMSs), it is basic to operate beyond thermodynamic equilibrium, requiring a continuous energy input. Light, due to its abundance, noninvasive nature, and precise spatial and temporal control, serves as an ideal energy source. This review highlights recent advances in bioinspired light-driven RMSs, with a particular focus on strategies to shift their activation wavelengths from UV to the visible and near-infrared regions through tailored structural modifications. A range of photochemical mechanisms underlying these systems, from reversible switching to unidirectional rotation, including emerging hybrid mechanisms that integrate multiple photophysical and/or chemical processes to achieve complex multistates behavior is discussed. Furthermore, it is explored that how specific molecular designs impact key photo-efficiency such as quantum yield and photostationary state distribution. These insights offer guiding principles to enhance the efficiency and functionality of RMSs and pave the way toward their integration in biomedical technologies requiring light-responsive control, such as targeted drug delivery and advanced imaging systems.

The Lewis pair 1, comprising an aromatic phosphinine and the strong Lewis acid B(C6F5)3, selectively activates the CN bonds in t BuNCO and t BuNCS. The experimental and computational studies confirmed the formation of a 1- t Bu-phosphininium salt, acting as a key intermediate. Unlike classical frustrated Lewis pairs, this method allows the alkylation of low-coordinated phosphorus compounds as a new approach.

The first example of a CN σ-bond activation in tert-butyl isocyanate and isothiocyanate by a 3,5-bis(trimethylsilyl)-phosphinine-B(C6F5)3 Lewis pair is reported. Despite the inherently low nucleophilicity of phosphinines, the first step of the observed reactions is the unusually facile tert-butylation of the phosphinine via an S N 1 pathway, yielding the unprecedented 1- t Bu-phosphininium cation. The high reactivity of this intermediate leads to subsequent follow-up reactions with the excess reactant as well as side-products, forming additional phosphorus compounds under mild conditions via a complex reaction network. In stark contrast, the reaction of t BuNCO and t BuNCS with a classical frustrated Lewis pair leads to simple decomposition of the iso(thio)cyanate. This work not only reveals a new mode of CN σ-bond activation in iso(thio)cyanates by compounds based on main-group elements, but also suggests a direct pathway for the selective P-functionalization of phosphinines, opening up avenues for the targeted synthesis of such otherwise inaccessible aromatic phosphorus heterocycles.

Tracking the propagation of periodic concentration perturbations within chemical reactions is presented as a powerful strategy for probing reaction connectivity and the kinetics of individual reaction steps. This approach is demonstrated here for the organocatalytic Michael-type addition of cyclopentadiene to α,β-unsaturated aldehydes, based on relative phase delays in ion intensities measured by electrospray ionization–mass spectrometry.

Periodic perturbations, such as modulations of reactant concentration, propagate through chemical reactions with distinct phase delays. Tracking the propagation of such perturbations presents a powerful approach for probing the reaction connectivity and the rates of individual reaction steps, provided that high-throughput and information-rich analytical approaches are used. Here, the online monitoring of periodic perturbations in the organocatalytic addition of cyclopentadiene to α, β-unsaturated aldehydes by electrospray ionization–mass spectrometry (ESI–MS) is reported. Upon perturbation of input concentrations, ion intensities corresponding to substrates and reaction intermediates detected by ESI–MS exhibit characteristic time delays, providing insights into the kinetics of individual reaction steps, as supported by numerical simulations. This study provides a novel framework for online reaction monitoring and mechanistic analysis in chemical systems.

Reacting 1-hydridosilatrane with triphenylcarbenium hexachloridoantimonate in acetonitrile solution and in the presence of 4-dimethylaminopyridine combines the world of silatranes with the world of carbenes, giving an unprecedented carbene-type antimony pentachloride complex. This finding offers a new playground for exciting new chemistry.

Silylium ions, three-coordinated as well as donor-stabilized, have attracted the interest of chemists for many years, have paved its way into practical application as catalysts for organic reactions, and have contributed to the understanding of fundamental chemistry problems. Since the first carbenes have been isolated and characterized, they had and still have an ongoing enormous impact on organic as well as on inorganic and organometallic chemistry. Herein, the synthesis and complete characterization of silatranyl cations as their acetonitrile- respectively propionitrile-coordinated hexachlorido antimonates is reported. Upon interaction of the former with 4-dimethylaminopyridine (DMAP) conversion to an unprecedented carbene–type complex of antimony pentachloride occurred, nicely combining silylium and carbene chemistry.

From axial and peripheral reactivity to remote derivatization, the chemical versatility of subphthalocyanines (SubPcs) renders them ideal scaffolds for the design of advanced functional materials. This review assembles the synthetic toolbox, key reaction conditions, and future challenges in SubPc functionalization, guiding the development of next-generation curved π-conjugated materials.

Subphthalocyanines (SubPcs) currently hold a privileged position among the most versatile scaffolds for the design of π-conjugated materials. In this context, the remarkable chemical tunability of these macrocycles has played a pivotal role, which has given rise to a unique and rich chemistry over the past two decades. Most recently, postfunctionalization strategies have been successfully applied at the axial ligand, the peripheral positions, and remote sites from the SubPc core. However, each of these approaches requires careful selection of reaction conditions, considering the high sensitivity of SubPcs against strong nucleophiles. In this review, a comprehensive overview of the full synthetic toolbox available for the postfunctionalization of SubPcs is provided. Special emphasis is placed on reaction conditions, functional group tolerance, and structural scope, as well as mechanistic insights when available. Finally, the main synthetic challenges that remain to be addressed in order to fully exploit the potential of SubPc chemistry are outlined. Altogether, this review aims to serve not only as a practical guide for chemists working in the field, but also as an inspiration for future developments in the chemistry of curved π-conjugated systems.

This review highlights the coordination chemistry of NHC bis-phenolate ligands with metal centers, emphasizing structural features, redox and optical properties, and catalytic applications. Key roles in polymerization, nitrogen reduction catalysis, and small molecule activation are discussed, showcasing the versatility and potential of [OCO]M complexes for future developments.

The present contribution comprehensively reviews the coordination chemistry of N-heterocyclic carbene (NHC) bis-phenolate tridentate ligand of the type [OCO] to various metal and heteroatom centers. The structural features of the resulting robust [OCO]M chelates are discussed along with their unique and specific properties, including emerging redox and optical properties of such complexes. Thanks to their stability and electronic features, this class of robust metal chelates has already been exploited for various catalytic applications, most notably the controlled polymerization of polar cyclic monomers and olefins, N2 reduction and photoinduced catalysis. In addition, some [OCO]M complexes have also been shown to stoichiometrically activate/functionalize small molecules such as O2 and NH3. All these aspects, some of them just emerging, are discussed herein along with future research opportunities on [OCO]M chelates.