Facile synthesis of N-Boc-(2S,5R)-5-(1′-hydroxy-1′-methylethyl)proline

Aminosulfonylation of Alkenes for the Synthesis of β-Amino Sulfone Derivatives

β-amino sulfones are important motifs found in natural products and active pharmaceutical compounds. Herein, we report a general and highly regioselective intermolecular aminosulfonylation of alkenes via the homolysis of sulfinyl oximes from ketoximes and sulfinyl chloride. This method features catalyst-free, step-efficient functionalization and prominent functional group tolerance, providing a straightforward, green, and widely applicable approach to accessing β-amino sulfone derivatives.

Arylthianthrenium Salts as the Aryl Sources: Visible Light/Copper Catalysis-Enabled Intermolecular Azidosulfonylation of Alkenes

The difunctionalization of alkenes using aryl thianthrenium salts as the aryl sources has been reported sporadically. However, the four-component difunctionalization of alkenes on the basis of aryl thianthrenium salts has not been reported thus far and still remains a challenge. Herein, a visible light/copper catalysis-enabled four-component reaction of aryl thianthrenium salts, DABCO·(SO2)2, alkenes, and TMSN3 is presented, which affords a facile approach to β-azidosulfones in good yields with broad substrate scope and excellent functional group tolerance. This strategy indirectly realizes the method for the synthesis of β-azidosulfones through site-selective aryl C-H bond functionalization and alkene difunctionalization. This developed method is an important complement to thianthrenium salts chemistry.

Regio- and Stereoselective Intermolecular 1,2-Difunctionalization of Terminal Alkynes: An Approach to Access (Z)-β-Amidovinylsulfones

We have developed the first I2/base-catalyzed regio- and stereoselective intermolecular β-amidosulfonylation of terminal alkynes using sodium sulfinates and quinoxalinone derivatives. The present methodology is compatible with a broad spectrum of various heterocyclic amides, terminal alkynes, and sodium sulfinates. It provides rapid access to valuable (Z)-β-amidovinyl sulfones at mild conditions. Moreover, the synthetic application of this methodology was demonstrated by the late-stage functionalization of numerous bioactive molecules.

Construction of β-Amino Sulfones from Sodium Metabisulfite via a Radical 1,4-Amino Migration

A three-component reaction of alkenyl-tethered oxime ethers, sodium metabisulfite, and aryldiazonium tetrafluoroborates under mild conditions is developed. This reaction proceeds at room temperature without any oxidants or additives, affording β-amino sulfones with good functional group tolerance through aminosulfonylation of unactivated alkene. Mechanistic studies show that this transformation undergoes a radical process, including radical trapping with sulfur dioxide and radical 1,4-amino migration.

Manganese(iii) acetate-mediated direct C(sp2)–H-sulfonylation of enamides with sodium and lithium sulfinates

A Mn(OAc)₃ mediated oxidative C(sp²)–H sulfonylation of enamides and encarbamates with sodium and lithium sulfinates is reported.