Copper-catalyzed oxidative cyclization of 2-(1-pyrrol-1-yl)aniline and alkylsilyl peroxides: a route to pyrrolo[1,2-]quinoxalines.

An efficient method was developed for the one-pot construction of pyrrolo[1,2-]quinoxalines a Cu(II)-catalyzed domino reaction between 2-(1-pyrrol-1-yl)anilines and alkylsilyl peroxides. This reaction proceeds through C-C bond cleavage and new C-C and C-N bond formation. A mechanistic study suggests that alkyl radical species participate in the cascade reaction.

Visible-light-catalyzed synthesis of 1,3-benzoxazines formal [4 + 2] cycloaddition of oximes with -hydroxybenzyl alcohols.

A formal [4 + 2] cycloaddition of oximes with -hydroxybenzyl alcohols was developed to easily synthesize diverse 1,3-benzoxazine derivatives. This synthesis was achieved under visible light-based organocatalytic and TsOH conditions. The reaction proceeds through the photoisomerization of oximes visible light-mediated energy transfer, followed by the nucleophilic attack of -QMs to oximes as a 1,2-dipole synthon, cyclization, and isomerization.

Secondary Metabolite Analysis of Phomopsis sp. LGT-5 Based on the Dual Guidance of Whole-Genome Sequencing and HPLC-Q-ToF-MS/MS.

Microorganisms produce a wealth of structurally diverse specialized metabolites with a remarkable range of biological activities. The Phomopsis sp. LGT-5 was obtained through tissue block and repeatedly crossed methods from Tripterygium wilfordii Hook.

Iron-Catalyzed Ring Expansion of Cyclobutanols for the Synthesis of 1-Pyrrolines by Using MsONHOTf.

The synthesis of 1-pyrrolines from cyclobutanol derivatives and an aminating reagent (MsONHOTf) has been developed. This one-pot procedure achieves C-N bond/C═N bond formation via ring expansion. A series of 1-pyrroline derivatives are synthesized in moderate to good yields under mild conditions.

I -Promoted Intramolecular Oxidative Cyclization of Butenyl Anilines: A Facile Route to Benzo[b]azepines.

A metal-free approach for the synthesis of seven-membered N-heterocycles has been developed by the I -promoted intramolecular cross-coupling/annulation of butenyl anilines. This cyclization reaction involves C-H activation and C-C bond formation and exhibits good functional group tolerance. A series of benzo[b]azepine derivatives are obtained in moderate to good yields.

A catalyst-free method for the synthesis of 1,4,2-dithiazoles from isothiocyanates and hydroxylamine triflic acid salts.

A catalyst-free method for the preparation of 1,4,2-dithiazoles is developed by reactions of isothiocyanates with hydroxylamine triflic acid salts. This reaction achieves C-S, C-N, and S-N bond formation, and a range of products are obtained in moderate to good yields. The obvious feature is using shelf-stable hydroxylamine triflic acid salts as a N source to synthesize heterocycles under mild conditions.

B(CF)-Catalyzed cyclization of alkynes: direct synthesis of 3-silyl heterocyclic compounds.

An efficient one-pot strategy for easy access to 3-silyl heterocyclic compounds was developed via a B(CF)-catalyzed cycloaddition reaction of o-(1-alkynyl)(thio)anisoles or o-(1-alkynyl)-N-methylaniline. In this reaction, benzenethiophene, benzofuran or indole skeletons could be constructed by an intermolecular cyclization with diphenylsilane. This protocol elicited moderate-to-good yields with metal-free reaction systems.

TFA-Catalyzed [3+2] Spiroannulation of Cyclobutanols: A Route to Spiro[cyclobuta[a]indene-7,1'-cyclobutane] Skeletons.

A straightforward method for the synthesis of spiro[cyclobuta[a]indene-7,1'-cyclobutane] derivatives from cyclobutanols has been developed via one-pot [3+2] spiroannulation. A series of new spiro[cyclobuta[a]indene-7,1'-cyclobutane] derivatives are facilely synthesized in good yields under mild reaction conditions.

A convenient access to allylic triflones with allenes and triflyl chloride in the presence of (EtO)P(O)H.

A simple method for the preparation of allylic triflones from allenes and triflyl chloride in the presence of (EtO)2P(O)H has been developed. The features of this reaction are catalyst-free and simple starting substrates. This method tolerates diverse functional groups and substituted allylic triflones are obtained in moderate to good yields.

Copper-catalyzed tandem aerobic oxidative cyclization for the synthesis of 4-cyanoalkylpyrrolo[1,2-a]quinoxalines from 1-(2-aminophenyl)pyrroles and cyclobutanone oxime esters.

A copper-catalyzed tandem ring-opening/cyclization reaction for the synthesis of 4-cyanoalkylpyrrolo[1,2-a]quinoxalines from 1-(2-aminophenyl)pyrroles and cyclobutanone oxime esters has been developed. This reaction involves C-C bond cleavage and C-C and C-N bond constructions with good functional group tolerance. A wide range of products are obtained in moderate to good yields under mild conditions.

Cleavage of C-C Bonds for the Synthesis of C2-Substituted Quinolines and Indoles by Catalyst-Controlled Tandem Annulation of 2-Vinylanilines and Alkynoates.

The strategy for the synthesis of C2-substituted indoles and quinolines from 2-vinylanilines and alkynoates through C-C bond cleavage is developed. With these general methods, 2-substituted indoles and quinolines can be accessed via tandem Michael addition and cyclization with no requirement of oxidant. This strategy not only provides a method for the synthesis C2-substituted indoles in good yields through the simultaneous cleavage of C═C and C≡C bonds under metal-free conditions but also provides a simple method for the generation of the C2-substituted quinolines in moderate yields via Pd-catalyzed C≡C bond cleavage.

FeCl-Catalyzed synthesis of pyrrolo[1,2-a]quinoxaline derivatives from 1-(2-aminophenyl)pyrroles through annulation and cleavage of cyclic ethers.

A straightforward Fe-catalyzed method for the synthesis of pyrrolo[1,2-a]quinoxalines from 1-(2-aminophenyl)pyrroles and cyclic ethers, which includes functionalization of C(sp)-H bonds and the construction of C-C and C-N bonds, has been developed. The features of this reaction are Fe catalysis, low-cost and readily accessible starting materials. Moreover, this procedure exhibits good functional group tolerance and a series of pyrrolo[1,2-a]quinoxaline derivatives are obtained in moderate to good yields.

tert-Butyl nitrite (TBN) as the N atom source for the synthesis of substituted cinnolines with 2-vinylanilines and a relevant mechanism was studied.

A green method to synthesize cinnolines by 6π electrocyclic reaction with alkenyl amines and TBN has been developed. TBN plays a dual role both as a nitrogen atom source and an oxidant in this procedure. Relevant mechanism experiments reveal that the reaction proceeds through electrocyclic reaction and with diazo hydroxide as a key intermediate.