Sulfinate-Engaged Nucleophilic Addition Induced Allylic Alkylation of Allenoates

Four-Component Radical 1,2-Selenosulfonylation of Allenes

Selenosulfones, as pivotal pharmaceutical molecule frameworks, have become a research hotspot in modern organic synthesis due to their vital need for efficient preparation. Herein, we have developed an iron-catalyzed four-component controllable radical tandem reaction of allenes involving cycloketone oxime esters, 1,4-diazabicyclo[2.2.2]octane bis(sulfur dioxide) adduct (DABSO), and diphenyl diselenides for the synthesis of complex selenosulfones. This is the first case of achieving the 1,2-selenosulfonylation of allenes via a radical process, wherein precise control of radical rates and polarity matching enhance high regioselective conversion. The reaction conditions are ecofriendly and mild with step-efficiency by forming two new C-S bonds and one C-Se bond in one pot. Moreover, the 1,2-selenosulfonylation of allenes can be achieved by replacing cycloketone oxime esters with aryldiazonium tetrafluoroborates in this system.

Palladium-catalysed fragmentary esterification-induced allylic alkylation of allyl carbonates and cyclic vinylogous anhydrides

An unprecedented palladium-catalysed fragmentary esterification-induced allylic alkylation (FEAA) of cyclic vinylogous anhydrides (CVAs) and allyl carbonates has been disclosed. The protocol features broad sp3-rich scaffold tolerance, rendering highly functionalized 1,6 and 1,7-dicarbonyls in up to high yields and diastereoselectivities. Three-component FEAA is also well tolerant to generate 1,6-dicarbonyls through the addition of extra O/N-nucleophiles. Furthermore, cyclic allyl carbonate-involved FEAA provides an efficient approach for the synthesis of structurally complex medium-sized rings.

Amino Acid Sulfinate Salts as Alkyl Radical Precursors

A general approach to the synthesis of amino acid sulfinate salts from commercially available α-chiral hydroxylated amino acids is reported. These reagents are shown to be valuable precursors to alkyl radicals under mild photochemical oxidation conditions. The photochemically generated amino acid radicals engage readily with alkyl and aryl disulfide radical traps to afford a diverse suite of modified amino acids.

Palladium(0)-Catalyzed Remote Decarboxylative Allylation and Base-Mediated 1,3-Migration

Herein we have reported the palladium(0)-catalyzed decarboxylative oxa-Michael addition/remote α-allylation/1,3- migration of prochiral allyl carbonate-tethered cyclohexadienones in good yields. This unconventional intramolecular rearrangement is triggered by the base-mediated retro-Michael ring-opening reaction (β-elimination) and subsequent syn-selective oxa-Michael addition on the less substituted enone functionality. The generality of tandem decarboxylative allylation was examined with various substrates and in the gram-scale reaction.

Visible-Light-Induced Tandem Reaction of Allenes with Selenesulfonates Leading to (E)-2,3-Disulfonylpropene Derivatives

A visible-light-induced tandem reaction of allenes with selenesulfonates was developed, providing (E)-2,3-disulfonylpropene derivatives in moderate to good yields. This reaction was featured with simple operation, good regioselectivity and stereoselectivity, and wide functional group tolerance. Photoinduced radical additions via energy transfer were proposed.

Synthesis of Vinylic Sulfones in Aqueous Media

A green method for the sulfination of allenic carbonyl compounds to access a wide variety of vinylic sulfones is developed. This reaction works in aqueous media under very mild conditions. This reaction is atom economic. A wide variety of vinylic sulfones could be obtained in moderate to excellent yields with wide functional group tolerance. The efficiency of this method is demonstrated in some reactions where the desired products can be isolated by filtration.