Photoinduced C(sp3 )-N Bond Cleavage Leading to the Stereoselective Syntheses of Alkenes.

Herein we report a versatile Mizoroki-Heck-type photoinduced C(sp3 )-N bond cleavage reaction. Under visible-light irradiation (455 nm, blue LEDs) at room temperature, alkyl Katritzky salts react smoothly with alkenes in a 1:1 molar ratio in the presence of 1.0 mol % of commercially available photoredox catalyst without the need for any base, affording the corresponding alkyl-substituted alkenes in good yields with broad functional-group compatibility. Notably, the E/Z-selectivity of the alkene products can be controlled by an appropriate choice of photoredox catalyst.

From Anilines to Aryl Ethers: A Facile, Efficient, and Versatile Synthetic Method Employing Mild Conditions.

We have developed a simple and direct method for the synthesis of aryl ethers by reacting alcohols/phenols (ROH) with aryl ammonium salts (ArNMe3+ ), which are readily prepared from anilines (ArNR'2 , R'=H or Me). This reaction proceeds smoothly and rapidly (within a few hours) at room temperature in the presence of a commercially available base, such as KOt Bu or KHMDS, and has a broad substrate scope with respect to both ROH and ArNR'2 . It is scalable and compatible with a wide range of functional groups.

Ethereal C-O Bond Cleavage Mediated by Ni(0)-Ate Complex: A DFT Study.

Density functional theory calculations were performed to explore the mechanism of Ni-catalyzed cross-coupling reactions involving organo-lithium and -zinc reagents through ethereal C-O bond cleavage. Based on this work, together with our previous mechanistic study on etheric Kumada-Tamao reaction, we identify and characterize a novel catalytic cycle for cross-coupling mediated by Ni(0)-ate complex.

Cross-Coupling of Organolithium with Ethers or Aryl Ammonium Salts by C-O or C-N Bond Cleavage.

Various aryl-, alkenyl-, and/or alkyllithium species reacted smoothly with aryl and/or benzyl ethers with cleavage of the inert C-O bond to afford cross-coupled products, catalyzed by commercially available [Ni(cod)2 ] (cod=1,5-cyclooctadiene) catalysts with N-heterocyclic carbene (NHC) ligands. Furthermore, the coupling reaction between the aryllithium compounds and aryl ammonium salts proceeded under mild conditions with C-N bond cleavage in the presence of a [Pd(PPh3 )2 Cl2 ] catalyst. These methods enable selective sequential functionalizations of arenes having both C-N and C-O bonds in one pot.

Cross-coupling polycondensation via C-O or C-N bond cleavage.

π-Conjugated polymers are widely used in optoelectronics for fabrication of organic photovoltaic devices, organic light-emitting diodes, organic field effect transistors, and so on. Here we describe the protocol for polycondensation of bifunctional aryl ethers or aryl ammonium salts with aromatic dimetallic compounds through cleavage of inert C-O/C-N bonds. This reaction proceeds smoothly in the presence of commercially available Ni/Pd catalyst under mild conditions, affording the corresponding π-conjugated polymers with high molecular weight. The method is applicable to monomers that are unreactive in other currently employed polymerization procedures, and opens up the possibility of transforming a range of naturally abundant chemicals into useful functional compounds/polymers.

Organozinc-Mediated Direct C-C Bond Formation via C-N Bond Cleavage of Ammonium Salts.

We report a direct cross-coupling reaction between diarylzinc (Ar2 Zn) and aryltrimethylammonium salts (ArNMe3+ ⋅- OTf) in the presence of LiCl, via C-N bond cleavage. The reaction takes place smoothly upon heating in THF without any external catalyst, enabling an efficient and chemoselective formation of biaryl products. Mechanistic studies indicate that the reaction proceeds through a single electron transfer route.

Stille coupling via C-N bond cleavage.

Cross-coupling is a fundamental reaction in the synthesis of functional molecules, and has been widely applied, for example, to phenols, anilines, alcohols, amines and their derivatives. Here we report the Ni-catalysed Stille cross-coupling reaction of quaternary ammonium salts via C-N bond cleavage. Aryl/alkyl-trimethylammonium salts [Ar/R-NMe3]+ react smoothly with arylstannanes in 1:1 molar ratio in the presence of a catalytic amount of commercially available Ni(cod)2 and imidazole ligand together with 3.0 equivalents of CsF, affording the corresponding biaryl with broad functional group compatibility. The reaction pathway, including C-N bond cleavage step, is proposed based on the experimental and computational findings, as well as isolation and single-crystal X-ray diffraction analysis of Ni-containing intermediates. This reaction should be widely applicable for transformation of amines/quaternary ammonium salts into multi-aromatics.