Publications by authors named "Jangam Jagadesh Kumar"

Benzoheteroles are promising structural scaffolds in the realm of medicinal chemistry, but sustainable synthesis of 2,3-difunctionalized benzoheterole derivatives is still in high demand. Indeed, we have conceptually rationalized the intrinsic reactivity of propargylic-enyne systems for the flexible construction of 2,3-disubstituted benzoheteroles through radical sulfonylative-cyclization cascade under organophotoredox catalysis. We hereby report an efficient visible-light-induced sulfonyl radical-triggered cyclization of 1,6-enynols with sulfinic acids under the dual catalytic influence of 4CzIPN and NiBr⋅DME, which led to the formation of 2,3-disubstituted benzoheteroles in good to high yields.

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Direct vicinal difunctionalization of π-systems has emerged as a powerful platform for constructing multiple bonds in a single synthetic operation using simple chemical feedstocks. Over the past decade, there has been exponential growth in the direct construction of successive C-S and C-I bonds using a wide variety of sulfonyl and iodide reactants through 1,2-iodosulfonylation of alkynes in a regio- and stereo-selective manner. In this review, we mainly focus on the recent developments in the preparation of β-iodovinyl sulfones and their practical applications in organic synthesis.

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Cycloannulative sulfonyl migration has received much attention; however, a carbon-to-carbon sulfonyl group shift still needs to be discovered. We hereby report a base-mediated oxa-Michael addition-elimination of ()-β-iodovinyl sulfones with -alkynylphenols, followed by cycloisomerization and unique stereoselective sulfonyl migration in one-pot, is realized under the influence of Mn(OAc)·2HO. A broad range of vinyl sulfone-tethered chromenes were readily accessed in moderate to high yields with good functional group compatibility.

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This review mainly focuses on recent developments in the preparation of β-keto sulfones and their extensive synthetic applications. New prospects for the synthesis of β-keto thiosulfones have also been highlighted. Over the last decade, there has been exponential growth in the direct construction of β-keto sulfones using a wide variety of keto and sulfonyl precursors.

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A practical, highly flexible and eco-friendly method has been developed for the synthesis of allyl thiosulfonates using Morita-Baylis-Hillman (MBH) allyl bromides and sodium arylthiosulfonates, which were readily assembled without any reagent/catalyst. Moreover, the allyl thiosulfonates were successfully transformed into a set of two synthetically viable diallyl disulfanes and unsymmetrical allyl disulfanes in the presence of CsCO. The present protocols are operationally simple and convenient to generate a wide range of functionalized allyl thiosulfonates and allyl disulfanes in good to excellent yields.

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