Comprehensive Profiling of Amine-Containing Metabolite Isomers with Chiral Phosphorus Reagents.

Metabolite isomers play diverse and crucial roles in various metabolic processes. However, in untargeted metabolomics analysis, it remains a great challenge to distinguish between the constitutional isomers and enantiomers of amine-containing metabolites due to their similar chemical structures and physicochemical properties. In this work, the triplex stable isotope -phosphoryl amino acids labeling (SIPAL) is developed to identify and relatively quantify the amine-containing metabolites and their isomers by using chiral phosphorus reagents coupled with high-resolution tandem mass spectroscopy.

Synthesis and Reactivity of an Anti-van't Hoff/Le Bel Compound with a Planar Tetracoordinate Silicon(II) Atom.

For a long time, planar tetracoordinate carbon (ptC) represented an exotic coordination mode in organic and organometallic chemistry, but it is now a useful synthetic building block. In contrast, realization of planar tetracoordinate silicon (ptSi), a heavier analogue of ptC, is still challenging. Herein we report the successful synthesis and unusual reactivity of the first ptSi species of divalent silicon present in , supported by the chelating bis(-heterocyclic silylene)bipyridine ligand, 2,2'-{[(4-BuPh)C(NBu)]SiNMe}(CN), ].

Where silylene-silicon centres matter in the activation of small molecules.

Small molecules such as H2, N2, CO, NH3, O2 are ubiquitous stable species and their activation and role in the formation of value-added products are of fundamental importance in nature and industry. The last few decades have witnessed significant advances in the chemistry of heavy low-coordinate main-group elements, with a plethora of newly synthesised functional compounds, behaving like transition-metal complexes with respect to facile activation of such small molecules. Among them, silylenes have received particular attention in this vivid area of research showing even metal-free bond activation and catalysis.

Zn(OTf)-Catalyzed Phosphinylation of Propargylic Alcohols: Access to γ-Ketophosphine Oxides.

The first facile and efficient Zn(OTf)-catalyzed direct coupling of unprotected propargylic alcohols with arylphosphine oxides has been developed, affording a general, one-step approach to access structurally diverse γ-ketophosphine oxides via sequential Meyer-Schuster rearrangement/phospha-Michael reaction along with new C(sp)-P and C═O bond formations, operational simplicity, and complete atom economy under ligand-free and base-free conditions.

Stable isotope N-phosphoryl amino acids labeling for quantitative profiling of amine-containing metabolites using liquid chromatography mass spectrometry.

Stable isotope chemical labeling liquid chromatography-mass spectrometry (LC-MS) is a powerful strategy for comprehensive metabolomics profiling, which can improve metabolites coverage and quantitative information for exploration of metabolic regulation in complex biological systems. In the current work, a novel stable isotope N-phosphoryl amino acids labeling strategy (SIPAL) has been successful developed for quantitative profiling of amine-containing metabolites in urine based on organic phosphorus chemistry. Two isotopic reagents, O- and O-N-diisopropyl phosphoryl l-alanine N-hydroxysuccinimide esters (O/O-DIPP-L-Ala-NHS), were firstly synthesized in high yields for labeling the amine-containing metabolites.

Copper-Catalyzed Direct Coupling of Unprotected Propargylic Alcohols with P(O)H Compounds: Access to Allenylphosphoryl Compounds under Ligand- and Base-Free Conditions.

The first facile and efficient copper-catalyzed direct C-P cross-coupling of unprotected propargylic alcohols with P(O)H compounds has been developed, providing a general, one-step approach to construct valuable allenylphosphoryl frameworks with operational simplicity and high step- and atom-economy under ligand-, base-, and additive-free conditions.

Main group metal-ligand cooperation of N-heterocyclic germylene: an efficient catalyst for hydroboration of carbonyl compounds.

N-heterocyclic ylide-like germylene effectively promotes the hydroboration of aldehydes and ketones under mild conditions with broad substrate tolerance, operational simplicity of procedure and excellent yields. A key intermediate in this catalytic system featuring a bicyclo[2,2,2]octane-like core has been successfully isolated and characterized, suggesting a new type of mechanism that involves the activation mode that mimics that of transition metal catalysts.