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N‐alkyl anilines are a series of common and versatile compounds which not only have been used as reaction solvents, acid‐accepters, and organic‐bases, but also in synthesis of dyes, pharmaceuticals, and anti‐colodal. The N‐methyl and/or N,N‐dimethyl anilines are the most representative ones among these. Due to their widespread uses, numerous works have been reported on synthetic strategies in the past decades. The studies on N−H methylations of anilines mainly focus on selection of reagents, selection of catalysts, or ligands design. Different transition‐metals, e. g., Ir, Ru, Pd, and et. al, with different ligands have been used in the methylation protocols. Methanol (CH3OH), carbon dioxide (CO2), formaldehyde (HCHO), or dimethyl carbonate ((CH3)2CO3) was used as C source, and hydrogen (H2) or silanes as H source. In this work, we would like to summarize the latest advances on the synthesis of N‐methyl (N,N‐dimethyl included) anilines and derivatives. This review provides an overview of reactants and catalyst, as well as an emphasis on the scope of substrates and proposed reaction mechanism for each work. [ABSTRACT FROM AUTHOR]

A one‐step protocol is described for the synthesis of arylacetaldehydes from aryl aldehydes or diaryl ketones by using the system of DMSO/KOH/zinc. In this transformation, DMSO provides a methine fragment that converts the −CHO structure in aryl aldehydes or the −CO− structure in diaryl ketones to the −CH2CHO structure in arylacetaldehydes via a one‐carbon extension. This protocol could also be used to synthesize arylacetaldehyde acetals from aryl aldehydes or diaryl ketones when zinc was replaced by diols. In this protocol, 25 examples of arylacetaldehydes and 26 examples of arylacetaldehyde acetals have been synthesized from aryl aldehydes or diaryl ketones. Based on control experiments and the literature, a plausible reaction mechanism is proposed in our work. [ABSTRACT FROM AUTHOR]

A transition‐metal‐free protocol for the synthesis of non‐terminal alkenyl ethers, alkenyl sulfides, and N‐vinylazoles from arylaldehydes or diarylketones, DMSO and O, S, N‐nucleophiles has been reported. In this protocol, 24 examples of non‐terminal alkenyl ethers and 28 examples of non‐terminal alkenyl sulfides in 72–95% yields have been synthesized within 5 min. Moreover, 27 examples of non‐terminal N‐vinylazoles with 57–88% yields have also been synthesized within 2 hours. The preliminary mechanism investigations revealed that arylaldehydes or diarylketones offered a carbon atom, DMSO provided a methine and O, S, N‐nucleophiles contributed one X atom for constructing C=C−X structure. [ABSTRACT FROM AUTHOR]

A protocol for the synthesis of terminal N‐vinylazoles from aromatic aldehydes, DMSO, and azoles has been reported. In this strategy, DMSO was involved in the construction of the C=C bond as a terminal carbon synthon. Both aromatic aldehydes and azoles could be well tolerated and give the corresponding terminal N‐vinylazoles in 52–91% yields. Based on preliminary experiments, a plausible mechanism is proposed. [ABSTRACT FROM AUTHOR]

A [3+1+1+1] cycloaddition was developed among 2‐arylpropene, ketone and DMSO in the presence of K2S2O8. 2‐arylpropene provides three carbons, ketone offers one carbon, and DMSO as dual carbon donor contributes two carbons to the six‐membered carbocycle. It gave the cyclohexene motif and spirocyclohexene skeleton. Four C−C bonds formed in this process. Both propylene and ketone could be well tolerated and give the corresponding cyclohexene or spirocyclohexene motif in useful yields. Based on the controlled experiments, a possible mechanism was proposed. [ABSTRACT FROM AUTHOR]

A new [3+2+1] annulation strategy based on the heteroatom‐free tri‐atom donor to synthesize 3,6‐dihydro‐2H‐pyrans has been developed. In this method, 2‐arylpropylene served as tri‐atom donor to contribute three carbon atoms, the heteroatom was provided by aldehyde, and DMSO served as one carbon donor and solvent. This annulation reaction gave 3,6‐dihydro‐2H‐pyrans in moderate to good yields. Based on the control experiments, a possible mechanism was proposed. [ABSTRACT FROM AUTHOR]

A copper acetate‐mediated reaction of benzaldehydes with nitromethane to synthesis of 3‐nitroisoxazoles is reported. A variety of nitro‐aryl‐disubstituted isoxazole derivatives can be prepared in moderate to good yields with benign functional group tolerance. This protocol is successfully applied in gram‐scale reaction. Preliminary mechanistic studies reveal that the aldehyde provided one carbon atom for the isoxazole ring, and nitromethane provided two carbon atoms and one nitrogen atom for the isoxazole ring. In this protocol, the C−O−N unit in the final isoxazole ring is formed from the rearrangement of nitromethane. [ABSTRACT FROM AUTHOR]