Regiodivergent Cobalt-Catalyzed Diels–Alder Reactions for the Synthesis of Bifunctional Building Blocks and Their Suzuki-Cross-Coupling Polymerizations

Relationships Between Defectivity and Porosity in High Surface Area Porous Aromatic Frameworks

Porous aromatic framework (PAF) microporosity is known to be strongly dependent on synthetic approach but little is known about why certain reactions yield significantly and consistently more porous PAFs. This article explores the connections between synthetic pathway, PAF defectivity, and microporosity. Using a network disassembly strategy, we show that defectivity is highly dependent on synthetic approach and that more defective PAFs are associated with lower surface areas and pore volumes. This empirical association is corroborated through systematic introduction of defects to a modelPAF, which results in significant reduction of apparent surface area and pore volumes. Taken together, these data suggest that only highly efficient coupling reactions should be targeted for the synthesis of ultra-high surface area porous aromatic frameworks.

Synthesis and reactivity of alkynyl boron compounds

Over the last century, there have been considerable developments in organoboron chemistry due to the stability, non-toxicity, and easy commercial availability of various boronic esters. Several organoboron reagents have emerged and play an increasingly important role in everyday organic synthesis. Among them, alkynyl boron compounds have attracted significant attention due to their easy synthesis and diverse reactivity. In this review, we summarize the advancement of research on alkynyl boron compounds, highlighting their importance in the synthesis of valuable compounds.

Pyridine(diimine) Iron Diene Complexes Relevant to Catalytic [2+2]-Cycloaddition Reactions

The synthesis, characterization, and catalytic activity of pyridine(diimine) iron piperylene and isoprene complexes are described. These diene complexes are competent precatalysts for (i) the selective cross-[2+2]-cycloaddition of butadiene or (E)-piperylene with ethylene and α-olefins and (ii) the 1,4-hydrovinylation of isoprene with ethylene. In the former case, kinetic analysis implicates the diamagnetic η4-piperylene complex as the resting state prior to rate-determining oxidative cyclization. Variable temperature 1H NMR and EXSY experiments established that diene exchange from the diamagnetic, 18e- complexes occurs rapidly in solution at ambient temperature through a dissociative mechanism. The solid-state structure of (Me(Et)PDI)Fe(η4-piperylene) (Me(Et)PDI = 2,6-(2,6-Me2-C6H3N═CEt)2C5H3N), was determined by single-crystal X-ray diffraction and confirmed the s-trans coordination of the monosubstituted 1,3-diene. Possible relationships between ligand-controlled diene coordination geometry, metallacycle denticity, and chemoselectivity of iron-mediated cycloaddition reactions are discussed.

Palladium-Catalyzed Difluoromethylation of Aryl Chlorides and Bromides with TMSCF2H

A palladium-catalyzed cross-coupling of aryl chlorides/bromides with TMSCF₂H is described. Two different catalysts, Pd(dba)₂/BrettPhos and Pd(P ^tBu₃)₂, are demonstrated and provide a variety of difluoromethylated arenes in good yields.

Metal-catalyzed regiodivergent organic reactions

This review discusses metal-catalysed regiodivergent additions, allylic substitutions, CH-activation, cross-couplings and intra- or intermolecular cyclisations.

Synergistic approach to polycycles through Suzuki-Miyaura cross coupling and metathesis as key steps

This account provides an overview of recent work, including our own contribution dealing with Suzuki–Miyaura cross coupling in combination with metathesis (or vice-versa). Several cyclophanes, polycycles, macrocycles, spirocycles, stilbenes, biaryls, and heterocycles have been synthesized by employing a combination of Suzuki cross-coupling and metathesis. Various popular reactions such as Diels–Alder reaction, Claisen rearrangement, cross-metathesis, and cross-enyne metathesis are used. The synergistic combination of these powerful reactions is found to be useful for the construction of complex targets and fulfill synthetic brevity.