A Concise Route to 2‐Sulfonylacetonitriles from Sodium Metabisulfite

Cyanation and cyanomethylation of trimethylammonium salts via electrochemical cleavage of C–N bonds

A practical and mild electrochemical protocol for cyanation and cyanomethylation of trimethylammonium salts has been developed.

The Renaissance of Alkali Metabisulfites as SO2 Surrogates

The upsurge of interest in the development of methodologies for the construction of sulfur-containing compounds via the use of expedient reagents has established sustainable tools in organic chemistry. This review focuses on sulfonylation reactions using inorganic sulfites (Na2S2O5 or K2S2O5) as the sulfur dioxide surrogates. Compared to the bis-adduct with DABCO, which is an excellent surrogate of gaseous SO2, the use of sodium or potassium metabisulfites as SO2 surrogates are equally efficient. The objective of the current review is to exemplify recent sulfonylation reactions using inorganic sulfites. For better understanding, the review is categorized according to the mode of reactions: transition-metal-catalyzed SO2 insertion, metal-free SO2 insertion, and visible-light-mediated SO2 insertion. All the reactions in each of the sections are illustrated with selected examples with a pertinent explanation of the proposed mechanism.

1 Introduction

2 Outlines of the Reactions Involving SO2 Insertion

2.1 Transition-Metal-Catalyzed SO2 Insertion

2.2 Transition-Metal-Free SO2 Insertion

2.3 Visible-Light-Mediated SO2 Insertion

3 Conclusion and Outlook

Photoinduced intramolecular carbosulfonylation of alkynes: access to sulfone-containing dibenzazepines from sulfur dioxide

A visible-light-driven three-component carbosulfonylation of terminal alkynes, DABCO (SO₂)₂ and aryldiazonium tetrafluoroborates is developed, leading to sulfone-containing dibenzazepines in moderate to good yields under mild conditions.

Metal-free sulfonylative annulations of alkyl diiodides with sulfur dioxide: synthesis of cyclic aliphatic sulfones

A straightforward protocol for cyclic aliphatic sulfones is effectively established via sulfonylative annulations of alkyl diiodides and gaseous sulfur dioxide. Five- to nine-membered cyclic aliphatic sulfones were afforded in this manner.