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Updated: Jan 19, 2026

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Completely Stereoselective Synthesis of Sulfonated 1,3-Dihydroisobenzofurans via Radical Multicomponent Reactions
Hao-Nan Shi1, Min-Hua Huang1,2, Chun-Lan He1
1School of Chemistry & Materials Science, Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials , Jiangsu Normal University , Xuzhou 221116 , P. R. China.
Abstract:
Two types of new oxidant-free radical multicomponent reactions of β-alkynyl ketones, aryldiazonium salts, and DABCO·(SO2)2 (DABSO) were established, leading to the tunable generation of two class of sulfonated 1,3-dihydroisobenzofurans with moderate to good yields and complete stereoselectivity under the mild conditions. The radical-induced scission/recombination of the C(sp3)-C(sp3) bond enabled direct 1,8-halosulfonylation of β-alkynyl ketones, giving 1,3-dimethylene-substituted (1Z,3Z)-1,3-dihydroisobenzofurans with substituent diversity by p-nitrobenzyl bromide (PNBB) or p-nitrobenzyl chloride (PNBC) as the halo source. Fine-tuning substituents to strong electron-withdrawing ones, such as nitro, cyano, and trifluoromethyl, linked to aryldiazonium tetrafluoroborates allowed a different annulation/1,5-azosulfonylation process to access sulfonated (Z)-1,3-dihydroisobenzofurans with one quaternary carbon-amino functionality.
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