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The construction of silicon‐stereogenic silanols via Pd‐catalyzed intermolecular C−H alkenylation with the assistance of a commercially available L‐pyroglutamic acid has been realized for the first time. Employing oxime ether as the directing group, silicon‐stereogenic silanol derivatives could be readily prepared with excellent enantioselectivities, featuring a broad substrate scope and good functional group tolerance. Moreover, parallel kinetic resolution with unsymmetric substrates further highlighted the generality of this protocol. Mechanistic studies indicate that L‐pyroglutamic acid could stabilize the Pd catalyst and provide excellent chiral induction. Preliminary computational studies unveil the origin of the enantioselectivity in the C−H bond activation step. [ABSTRACT FROM AUTHOR]

The precise control of the regioselectivity in the transition metal‐catalyzed migratory hydrofunctionalization of alkenes remains a big challenge. With a transient ketimine directing group, the nickel‐catalyzed migratory β‐selective hydroarylation and hydroalkenylation of alkenyl ketones has been realized with aryl boronic acids using alkyl halide as the mild hydride source for the first time. The key to this success is the use of a diphosphine ligand, which is capable of the generation of a Ni(II)‐H species in the presence of alkyl bromide, and enabling the efficient migratory insertion of alkene into Ni(II)‐H species and the sequent rapid chain walking process. The present approach diminishes organosilanes reductant, tolerates a wide array of complex functionalities with excellent regioselective control. Moreover, this catalytic system could also be applied to the migratory hydroarylation of alkenyl azahetereoarenes, thus providing a general approach for the preparation of 1,2‐aryl heteroaryl motifs with wide potential applications in pharmaceutical discovery. [ABSTRACT FROM AUTHOR]

The use of molecular oxygen as the terminal oxidant in transition metal catalyzed oxidative process is an appealing and challenging task in organic synthetic chemistry. Here, we report a Ni‐catalyzed hydroxylarylation of unactivated alkenes enabled by a β‐diketone ligand with high efficiency and excellent regioselectivity employing molecular oxygen as the oxidant and hydroxyl source. This reaction features mild conditions, broad substrate scope and incredible heterocycle compatibility, providing a variety of β‐hydroxylamides, γ‐hydroxylamides, β‐aminoalcohols, γ‐aminoalcohols, and 1,3‐diols in high yields. The synthetic value of this methodology was demonstrated by the efficient synthesis of two bioactive compounds, (±)‐3′‐methoxyl citreochlorol and tea catechin metabolites M4. [ABSTRACT FROM AUTHOR]

In contrast to the vast Al‐oxo molecular cluster chemistry, Al‐based building units for metal–organic framework (MOF) construction are limited in structural diversity and complexity. Synthesis of single crystalline MOFs based on this "hard" metal is further complicated by the poor reversibility of the Al‐organic coordination linkages. Here, a strategy to employ two kinds of linkages with distinct strength—strong Al‐carboxylate linkage and weak Cu‐pyrazol N linkage—gives FDM‐91 (FDM=Fudan Materials) with gigantic Al24‐based units. After replacing the weak moieties with organic linkers post‐synthetically, two new stable MOFs with exceptional water harvesting capacity (up to 0.53 g g−1) and outstanding cycling performance are developed. Linkage‐selective dissociation of FDM‐91 further leads to the isolation of the Al24 molecular clusters. The versatile chemistry performed here to reinforce or deconstruct MOFs provides a new way to make important extended and discrete structures. [ABSTRACT FROM AUTHOR]

The transition metal‐catalyzed cross‐coupling reaction with Fischer metal carbene intermediates bearing an electron‐rich alkoxyl or siloxyl group remains a big challenge due to the lack of readily available corresponding carbene precursors. Herein, we report the coupling of alkynes with the Fischer‐type copper carbene species bearing a α‐siloxyl group, which could be in situ generated from acylsilanes catalytically under photoirradiation and redox‐neutral conditions. The side‐arm modified bisoxazoline (SaBox) ligands prove to be crucial for this coupling reaction, which provides the corresponding alkynyl alcohol in high yields with remarkable heterocycle tolerance and broad substrate scope. [ABSTRACT FROM AUTHOR]

Enantiopure monohydrosilanes are versatile chiral reagents for alcohol resolution and mechanistic investigation. Herein, we have demonstrated the asymmetric synthesis of monohydrosilanes via an intramolecular hydrosilylation strategy. This protocol is suitable for the synthesis of five‐ and six‐membered cyclic monohydrosilanes, including a class of chiral oxasilacycles, with excellent diastereo‐, regio‐, and enantioselectivities. Notably, the catalyst loading could be reduced to 0.1 mol % which makes this one of the most efficient methods to access chiral monohydrosilanes. Mechanistic studies and DFT calculations indicate this Rh‐catalyzed intramolecular asymmetric hydrosilylation reaction might proceed via a Chalk–Harrod mechanism, and the enantio‐determining step was predicted to be oxidative addition of Si−H bond. [ABSTRACT FROM AUTHOR]

A new metal–organic framework (MOF) with both coordination linkages and covalent linkages is prepared by coordinating CuI with pyrazolate for an aldehyde‐functionalized trinuclear complex, and subsequent imine condensation with p‐phenylenediamine, a reaction typical for covalent organic framework (COF) synthesis. This MOF×COF collaboration yields FDM‐71 with honeycomb layers stacked in eclipsed fashion. After dissociating the CuI‐pyrazolate coordination in FDM‐71, the obtained organic components carry the information of structural defects, and thus vacancy identity (aldehyde‐based unit vacancy and amine‐based unit vacancy) and concentration are definitely resolved. Further to the redox catalytic activity inherited from the complex, FDM‐71 features effective photosensitizing activity. The two functions integrated in one well‐defined structure is demonstrated by its high efficiency in decomposing H2O2 and consequent excitation of O2 to reactive oxygen species. [ABSTRACT FROM AUTHOR]

The synthesis of N-arylimidazoles substituted at the sterically encumbered 5-position is a challenge for modern synthetic approaches. A new family of imidazolyl aryliodonium salts is reported, which serve as a stepping stone on the way to selective formation of N1-aryl-5-iodoimidazoles. Iodine acts as a 'universal' placeholder poised for replacement by aryl substituents. These new λ3-iodanes are produced by treating the NH-imidazole with ArI(OAc)2, and are converted to N1-aryl-5-iodoimidazoles by a selective copper-catalyzed aryl migration. The method tolerates a variety of aryl fragments and is also applicable to substituted imidazoles. [ABSTRACT FROM AUTHOR]