Photoredox-Catalyzed Four-Component Reaction for the Synthesis of Complex Secondary Amines

Abstract

The one-pot sulfonylation/aminoalkylation of styrene derivatives furnishing substituted γ-sulfonylamines was accomplished through a photoredox-catalyzed four-component reaction. Besides one molecule of water and the sodium counterion of the sulfinate, all atoms of the starting materials are transferred to the final product, rendering this process highly atom-efficient. The operationally simple protocol allows for the simultaneous formation of three new single bonds (C–S, C–N, and C–C) and therefore grants rapid access to structurally diverse products.

Recent Advances in Multicomponent Reactions with Organic and Inorganic Sulfur Compounds

“…Opatz and co‐workers reported a one‐pot and photoredox‐catalyzed four‐component sulfonylation/aminoalkylation of styrenes to afford substituted γ‐sulfonylamines 120 (Scheme 31). [74] The prominent advantages of this method are relatively broad substrate spectrum, good functional group tolerance and highly atom economic process.…”

Oxidative Sulfonylation of Multiple Carbon‐Carbon bonds with Sulfonyl Hydrazides, Sulfinic Acids and their Salts

“…This group proposed one-pot sulfonylation-aminoalkylation of styrene derivatives furnishing substituted γ-sulfonylamines through a photoredoxcatalyzed four-component reaction. [107] The C-centered radicals resulting from the addition of the sulfonyl radicals to the double bond were also intercepted by quinoxaline-2(1H)-ones 184 providing sulfonylmethyl derivatives 185 (Scheme 86). [108] Three-component reaction between alkynes 186, sodium sulfinates 188, and Togni reagent 187 was performed in DMSO at room temperature without the addition of any oxidizing agents and catalysts.…”

“…Finally, recombination of C with radical anion A and elimination of cyanide anion from intermediate D leads to the target product 181 (Scheme 85). This group proposed one‐pot sulfonylation‐aminoalkylation of styrene derivatives furnishing substituted γ‐sulfonylamines through a photoredox‐catalyzed four‐component reaction [107] …”

α-Functionalization of Imines via Visible Light Photoredox Catalysis

“…In most cases, the imine reduction is believed to be assisted by coordination to an external acidic species. A unique example based on the reactivity of these α-amino radicals was reported by Opatz featuring a four-component reaction which gave access to structurally diverse products (Scheme 14) [41]. The protocol involved the simultaneous construction of three new bonds: C-N (via in situ formation of the imine), C-S (via sulfonyl radical addition to styrene) and C-C (via α-amino radical-benzyl radical coupling).…”