Slipping boron into alkyl ethers The carbon–oxygen bonds that hold together are relatively inert. Lyu et al. report zinc and nickel can team up to insert between the carbon oxygen using an unusual mechanism. First, a dibromoborane pries open bond with help from ion. Next, stitches boron, oxidation of metallic starts cycle over again. Versatile reactivity at inserted center then add carbons original ether or swap out for nitrogen. Science , this issue p. 175

Abstract Supramolecular polymer networks contain non-covalent cross-links that enable access to broadly tunable mechanical properties and stimuli-responsive behaviors; the incorporation of multiple unique within such materials further expands their responses functionality. To date, however, design has been accomplished through discrete combinations distinct interaction types in series, limiting logic. Here we introduce concept leveraging “nested” supramolecular crosslinks, wherein two...

Using a mechanically guided ligand design approach, new (SEGFAST) for the CuH-catalyzed hydroamination reaction of unactivated terminal olefins has been developed, providing 62-fold rate increase over reactions compared to DTBM-SEGPHOS, previous optimal ligand. Combining respective strengths computational chemistry and experimental kinetic measurements, we were able quickly identify potential modifications that lead more effective ligands, thus avoiding synthesizing testing large library...

Stereoselective manipulations at the C1 anomeric position of saccharides are one central goals preparative carbohydrate chemistry. Historically, majority reactions forming a bond with carbon has focused on nucleophiles saccharide donors equipped leaving group. Here, we describe novel approach to stereoselective synthesis C-aryl glycosides capitalizing highly stereospecific reaction nucleophiles. First, methods for preparation stannanes have been developed and optimized afford both anomers...

Convenient strategies for the deconstruction and reprocessing of thermosets could improve circularity these materials, but most approaches developed to date do not involve established, high-performance engineering materials. Here, we show that bifunctional silyl ether, i.e., R'O-SiR2-OR'', (BSE)-based comonomers generate covalent adaptable network analogues industrial thermoset polydicyclopentadiene (pDCPD) through a novel BSE exchange process facilitated by low-cost food-safe catalyst...

Polymers that release small molecules in response to mechanical force are promising candidates as next-generation on-demand delivery systems. Despite advancements the development of mechanophores for releasing diverse payloads through careful molecular design, availability scaffolds capable discharging biomedically significant cargos substantial quantities remains scarce. In this report, we detail a nonscissile mechanophore built from an 8-thiabicyclo[3.2.1]octane 8,8-dioxide (TBO) motif...

Hydrogen fluoride (HF) is a versatile reagent for material transformation, with applications in self-immolative polymers, remodeled siloxanes, and degradable polymers. The responsive situ generation of HF materials therefore holds promise new classes adaptive systems. Here, we report the mechanochemically coupled from alkoxy-gem-difluorocyclopropane (gDFC) mechanophores derived addition difluorocarbene to enol ethers. Production involves an initial assisted rearrangement gDFC mechanophore...

The aza Paternò-Büchi reaction is a [2+2]-cycloaddition between imines and alkenes that produces azetidines, four-membered nitrogen-containing heterocycles. Currently, successful examples rely primarily on either intramolecular variants or cyclic imine equivalents. To unlock the full synthetic potential of reactions, it essential to extend acyclic Here, we report matching frontier molecular orbital energies with those oximes enables visible light-mediated reactions through triplet energy...

Nickel catalysis offers exciting opportunities to address unmet challenges in organic synthesis. Herein we report the first nickel-catalyzed radical migratory cross-coupling reaction for direct preparation of 2-aryl-2-deoxyglycosides from readily available 1-bromosugars and arylboronic acids. The features a broad substrate scope tolerates wide range functional groups complex molecular architectures. Preliminary experimental computational studies suggest concerted 1,2-acyloxy rearrangement...

The immobilization of homogeneous catalysts onto supports to improve recyclability while maintaining catalytic efficiency is often a trial-and-error process limited by poor control the local catalyst environment and few strategies append support materials. Here, we introduce modular heterogenous catalysis platform that addresses these challenges. Our approach leverages well-defined interiors self-assembled Pd12L24 metal–organic cages/polyhedra (MOCs): simple mixing catalyst-ligand choice...

The challenge of direct partial oxidation methane to methanol has motivated the targeted search metal–organic frameworks (MOFs) as a promising class materials for this transformation because their site-isolated metals with tunable ligand environments. Thousands MOFs have been synthesized, yet relatively few screened promise in conversion. We developed high-throughput virtual screening workflow that identifies from diverse space experimental not studied catalysis, are thermally stable,...

The absence of a synthetic catalyst that can selectively oxidize methane to methanol motivates extensive study single-site catalysts possess high degree tunability in their coordination environments and share similarities with natural enzymes catalyze this reaction. Single-atom (SACs), particular doped graphitic SACs, have emerged as promising family materials due atom economy scalability, but SACs are yet be exhaustively screened for methane-to-methanol conversion. Modulating the...

2,3-Dihydrobenzofurans and indolines are common substructures in medicines natural products. Herein, we describe a method that enables direct access to these core structures from non-conjugated alkenyl amides ortho-iodoanilines/phenols. Under palladium(II) catalysis this [3 + 2] heteroannulation proceeds an anti-selective fashion tolerates wide variety of functional groups. N-Acetyl, -tosyl, -alkyl substituted ortho-iodoanilines, as well free -NH

C3-substituted 1H-indazoles are useful and important substructures in many pharmaceuticals. Methods for direct C3-functionalization of indazoles relatively rare, compared to reactions developed the more nucleophilic N1 N2 positions. Herein, we report a highly C3-selective allylation reaction 1H-N-(benzoyloxy)indazoles using CuH catalysis. A variety C3-allyl with quaternary stereocenters were efficiently prepared high levels enantioselectivity. Density functional theory (DFT) calculations...

The tearing of a polymer network arises from mechanochemically coupled bond-breaking events in the backbone chain. An emerging research area is identification molecular strategies for toughening, such as strategic placement reactive groups (e.g., scissile mechanophores) crosslinks instead load-bearing primary strands. These mechanically labile crosslinkers have typically relied on release ring strain or weak covalent bonds selective bond scission. Here, we report novel chemical design...

The recognition of latent symmetry in delavatine A has enabled a short synthesis the natural product starting from 3,5-dibromo-2-pyrone. concise synthetic route features cascade process involving 6π electrocyclization to construct indane core A. In addition, we have conducted detailed experimental and computational studies gain an in-depth understanding mechanism observed site-selective cross-coupling This insight may provide new avenues achieve selective multiply halogenated heteroarenes.

Two distinct N-containing POCs show exceptional Br 2 vapor adsorption ability and different reversibility of by forming charge-transfer complexes with polybromide species, as demonstrated experimental investigations DFT calculations.

The cis- and trans-isomers of a silacycloheptene were selectively synthesized by the alkylation silyl dianion, novel approach to strained cycloalkenes. trans-silacycloheptene (trans-SiCH) was significantly more than cis isomer, as predicted quantum chemical calculations confirmed crystallographic signatures twisted alkene. Each isomer exhibited distinct reactivity toward ring-opening metathesis polymerization (ROMP), where only trans-SiCH afforded high-molar-mass polymer under...

Metal-organic cages/polyhedra (MOCs) are versatile building blocks for advanced polymer networks with properties that synergistically blend those of traditional polymers and crystalline frameworks. Nevertheless, constructing polyMOCs from very stable Pt(II)-based MOCs or mixtures metal ions such as Pd(II) Pt(II) has not, to our knowledge, been demonstrated, nor exploration how the dynamics metal-ligand exchange at MOC level may impact bulk polyMOC energy dissipation. Here, we introduce a new...

Single-walled carbon nanotubes (SWCNTs) have been widely applied in biomedical fields such as drug delivery, biosensing, bioimaging, and tissue engineering. Understanding their reactivity with biomolecules is important for these applications. We describe here a photoinduced cycloaddition reaction between enones SWCNTs. By creating covalent tunable sp3 defects the sp2 lattice of SWCNTs through [2π + 2π] photocycloaddition, bright red-shifted photoluminescence was gradually generated. The...

Second row elements in small- and medium-rings modulate strain. Herein we report the synthesis of two novel oligosilyl-containing cycloalkynes that exhibit angle-strain, as observed by X-ray crystallography. However, angle-strained sila-cyclooctynes are sluggish participants cycloadditions with benzyl azide. A distortion-interaction model analysis based on density functional theory calculations was performed.