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An effective protocol of photoredox catalyzed C2-alkylation of benzothiazoles with aliphatic carboxylic acids was disclosed. In the presence of an acridinium salt as a photocatalyst and air as an oxidant, a wide range of secondary or tertiary aliphatic ca

A visible light-induced decarboxylative alkylation of heterocyclic aromatics with aliphatic carboxylic acids was developed by using anthocyanins as a photocatalyst under mild conditions. A series of alkylated heterocyclic compounds were obtained in modera

Herein we report a protocol for the visible-light-mediated alkylation/acylation reaction of benzothiazoles. Alkyl/acyl substituted Hantzsch esters are easily prepared and rationally used as radical precursors. In the presence of BF3·Et2O and Na2S2O8, various benzothiazole derivatives were readily obtained in good yields. Our user-friendly protocol can proceed by simple irradiation with blue LEDs (λ = 465 nm) and without the assistance of external photocatalysts. The reaction is also characterized by mild conditions and scalability, thus offering an alternative and efficient tool for the synthesis of 2-functionalized benzothiazoles.

A novel strategy of cascade radical C(sp2/sp3)-S bond cleavage and group-transfer cyclization is disclosed. Triggered by alkyl radicals, varieties of 2-isocyanoaryl thioethers containing aliphatic, aryl, and heteroaromatic groups can be cleaved and precisely reinstalled to give benzothiazole derivatives. Mechanistic studies reveal that the cascade reaction undertakes an intermolecular pathway, and the inner radical sources (R radicals) exhibit high priority over those of methyl radical origin from di-tert-butyl peroxide.

An efficient and environmentally benign method was developed for the facile synthesis of various 2-aryl and 2-alkyl substituted benzothiazoles in moderate to good yields, using a silver-mediated redox condensation of benzothiazoles and aldehydes in water. Furthermore, this method is also applicable to prepare 2-acyl benzothiazoles.

An efficient, iron-catalyzed C-H alkylation of benzothiazoles by using alkyl diacyl peroxides and alkyl tertbutyl peresters which are readily accessible from carboxylic acids to synthesize 2-alkylbenzothiazoles is developed. This reaction is environmentally benign and compatible with a broad range of functional groups. Various primary, secondary, and tertiary alkyl groups can be efficiently incorporated into diverse benzothiazoles. The effectiveness of this method is illustrated by late-stage functionalization of biologically active heterocycles.

A novel and efficient silver catalyzed decarboxylative direct C2-alkylation of benzothiazoles with carboxylic acids for the synthesis of 2-alkyl benzothiazoles was developed.

Synthetic methods: The Ni-catalyzed alkylation of 2-(methylthio) benzothiazoles through C-S bond cleavage is reported. Reactions with various secondary alkyl nucleophiles proceeded efficiently in the presence of 1,3-butadiene as an additive. This reaction was proposed to proceed by σ-bond metathesis between the thioether and a bis(π-allyl)nickel complex or by an addition/elimination mechanism involving the C=34;N double bond of the benzothiazoles (see scheme). Copyright

Bistrimethylsilylperoxide 1 reacts with 2-benzothiazolylalkyllithiums 3 leading to alkylbenzothiazoles 2, and to benzothiazolylalkyl silyl ethers 4.The reacton of 1 with 3 leading to 2 represents the first example of demethylation of 1.The reaction of 2-benzothiazolyllithium 2g with 1 leads mainly to 2-hydroxybenzothiazole 2h.

Thiols add to allenylnitriles to give unconjugated nitriles which may be isomerised to conjugated enesulphide nitriles either at high temperature (200o) or with base.Phenylpropynenitrile gives conjugated adducts directly.Heating the conjugated adducts from aminoethanethiols at >200o results in 5-exotrig ring closure and elimination of acetonitrile to give thiazolines and benzothiazoles.