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Abstract The transition‐metal‐catalyzed Suzuki‐Miyaura cross‐coupling (SMC) reaction of organoboron nucleophiles with aryl (pseudo)halide electrophiles is a reliable method for carbon‐carbon bond formation. This reaction generally requires the use of an exogenous base to promote transmetalation process, which limits the substrate scope of the reaction due to undesired protodeboronation and functional group incompatibilities. Here, we established a base‐free SMC reaction via a conceptually different electrophilic substitution transmetalation (EST). This transformation is applicable to a wide range of base‐sensitive and sterically hindered organoborons. Key to this advance is the formation of a stable cationic palladium(II) or nickel(II) intermediate via experimental and theoretical investigations. In a broader context, this research further expands the synthetic boundary of cross‐coupling chemistry. 

Group 13 aminoxy complexes, (L)E(TEMPO)₃(TEMPO = 2,2,6,6-tetramethylpiperidine 1-oxyl; L = THF (tetrahydrofuran) or Py (pyridine); E = Al, Ga, In), display ambiphilic reactivity with H₂and function as synthons for the preparation of materials. 

Abstract While enantioenriched alcohols are highly significant in medicinal chemistry, total synthesis, and materials science, the stereoselective synthesis of tertiary alcohols with two adjacent stereocenters remains a formidable challenge. In this study, we present a dual catalysis approach utilizing photoredox and nickel catalysts to enable the unprecedented chemoselective functionalization of tertiary allylic C−H bonds in allyl ethers instead of cleaving the C−O bond. The resulting allyl‐Ni intermediates can undergo coupling with various aldehydes, facilitating a novel enantioconvergent approach to access extensively functionalized homoallylicsec,tert‐vicinal diols frameworks. This protocol exhibits nice tolerance towards functional groups, a broad scope of substrates, excellent diastereo‐ and enantioselectivity (up to 20 : 1 dr, 99 %ee). Mechanistic studies suggested that allyl‐Ni^IIacts as the nucleophilic species in the coupling reaction with carbonyls. 

Ground state destabilization is a promising strategy to modulate rotational barriers in amphidynamic crystals. DFT studies of polar phenylenes installed as rotators in pillared-paddle wheel metal-organic frameworks were performed to investigate the effects of ground state destabilization on their rotational dynamics. We found that as the steric size of phenylene substituents increases the ground state destabilization effect is also increased. Specifically, a significant destabilization of the ground state energy occurred as the size of the substituents increased, with values ranging from 2 kcal/mol to 11.7 kcal/mol. An evalua-tion of the effects of substituents on dipole-dipole interaction energies and rotational barriers suggest that it should be possi-ble to engineer amphidynamic crystals where the dipole-dipole interaction energy becomes comparable to the rotational barri-ers. Notably, dipole-dipole interaction energies reached values ranging from 0.6 kcal/mol to 2.4 kcal/mol. We propose that careful selection of polar substituents with different size may help create temperature-responsive materials with switchable collective polarization. 

Abstract Cyclobutanes are prominent structural components in natural products and drug molecules. With the advent of strain‐release‐driven synthesis, ring‐opening reactions of bicyclo[1.1.0]butanes (BCBs) provide an attractive pathway to construct these three‐dimensional structures. However, the stereoselective difunctionalization of the central C−C σ‐bonds remains challenging. Reported herein is a covalent‐based organocatalytic strategy that exploits radical NHC catalysis to achieve diastereoselective acylfluoroalkylation of BCBs under mild conditions. The Breslow enolate acts as a single electron donor and provides an NHC‐bound ketyl radical with appropriate steric hindrance, which effectively distinguishes between the two faces of transient cyclobutyl radicals. This operationally simple method tolerates various fluoroalkyl reagents and common functional groups, providing a straightforward access to polysubstituted cyclobutanes (75 examples, up to >19 : 1 d.r.). The combined experimental and theoretical investigations of this organocatalytic system confirm the formation of the NHC‐derived radical and provide an understanding of how stereoselective radical‐radical coupling occurs.