Synthesis of 2,5-asymmetrically substituted 3,4-diaminothieno[2,3-b]thiophenes by domino reaction

Visible-Light-Induced Oxidative α-keto-Dichlorination of Arylalkynes by CuCl2 at Room Temperature

A visible light-induced oxidative α-keto-dichlorination of terminal and internal aryl alkynes was developed to form dichloroacetophenones (DCAPs) and dichlorophenyl-acetophenones (DCPAPs), respectively, by using CuCl₂ as a photoredox catalyst in the presence of air at room temperature (without using any exogenous photocatalyst). Here, photoexcited CuCl₂ underwent ligand-to-metal charge transfer to generate a Cl radical, which readily added to the alkynes to form DCAPs or DCPAPs in the presence of O₂ . This α-keto-dichlorination reaction is a green and mild protocol as it produced water as the only by-product. Moreover, the evaluation of green chemistry metrics indicated that the E-factor (mass of wastes/mass of products) of the current α-keto-chlorination method is around 10.1 times lower than that of a literature-reported photochemical method. The Eco Scale value (score 55, which on a scale of 0-100 indicates an acceptable synthesis) signifies that this process is simple, highly efficient, eco-friendly, and cost-effective.

Synthesis of Biologically Active Heterocycles via a Domino Sequence Involving an SN2/Thorpe–Ziegler Reaction Step

This review highlights methods for the synthesis of five- and six-membered heterocycles and their annulated analogues. These methods are based on anionic domino reactions that have a common step: an SN2/Thorpe–Ziegler reaction. In addition, data on the biological activity of these heterocycles are summarized.

1 Introduction

2 Synthesis of Thiophenes, Pyrroles, Furans and Other Heterocycles

2.1 Synthesis of 3-Aminothiophenes

2.2 Synthesis of 3-Aminopyrroles

2.3 Synthesis of 3-Aminofurans

3 Synthesis of Bicyclic Heterocyclic Systems

3.1 Thiophenes, Pyrroles and Furans Fused with Five-Membered Heterocycles

3.2 Thiophenes, Pyrroles and Furans Fused with Six-Membered Heterocycles

4 Synthesis of Heterocyclic Compounds Using Three-Step Domino Reactions

5 Synthesis of Heterocyclic Compounds Based on a Combination of Two Domino Reactions

6 Miscellaneous

7 Conclusion

Recent strategies in the synthesis of thiophene derivatives: highlights from the 2012-2020 literature

Thiophene-based analogs have been fascinated by a growing number of scientists as a potential class of biologically active compounds. Furthermore, they play a vital role for medicinal chemists to improve advanced compounds with a variety of biological effects. The current review envisioned to highlight some recent and particularly remarkable examples of the synthesis of thiophene derivatives by heterocyclization of various substrates from 2012 on.

Chiral-at-Metal Rh(III) Complex Catalyzed Cascade Reduction-Michael Addition Reaction

An enantioselective three-component cascade reduction-Michael addition reaction catalyzed by chiral-at-metal Rh(III) complexes has been developed. With a Hantzsch ester as the hydride source, a number of malononitrile derivatives were prepared in good yields and excellent enantioselectivities. A model that accounts for the origin and influence factors of the stereoselectivity has been proposed based on experiments.

An Efficient Synthesis of Acenaphtho[1,2-b]indole Derivatives via Domino Reaction

A concise and efficient synthesis of acenaphtho[1,2-b]indole derivatives via the domino reactions of enaminones with acenaphthoquinone catalyzed by l-proline has been developed. This protocol has the advantages of good yields, operational convenience and high regioselectivity.

Crystal structure of 1,1′-(3,4-diphenylthieno[2,3-b]thiophene-2,5-diyl)bis[1-phenyl-methanone], C32H20O2S2

C32H20O2S2, monoclinic, P21/c (no. 14), a = 10.2763(8) Å, b = 19.9178(15) Å, c = 11.8597(10) Å, β = 92.828(3)°, V = 2424.3(3) Å3, Z = 4, R gt(F) = 0.069, wR(F 2) = 0.1782, T = 293(2).

Efficient synthesis and evaluation of antitumor activities of novel functionalized 1,8-naphthyridine derivatives

An efficient synthesis of novel functionalized 1,8-naphthyridine and chromeno[2,3-b]quinoline derivatives via cascade reaction of 2-chloroquinoline-3-carbaldehyde and enaminones or cyclic 1,3-dicarbonyl compounds was developed. All of the 1,8-naphthyridine derivatives synthesized were evaluated for their antiproliferative properties in vitro against cancer cells and several compounds were found to have high activities.