Regiodivergent sulfonylarylation of 1,3-enynes via nickel/photoredox dual catalysis

Abstract

Catalytic difunctionalization of 1,3-enynes represents an efficient and versatile approach to rapidly assemble multifunctional propargylic compounds, allenes and 1,3-dienes. Controlling selectivity in such addition reactions has been a long-standing challenging...

Dual Photoredox/Nickel-Catalyzed 1,4-Sulfonylarylation of 1,3-Enynes with Sulfinate Salts and Aryl Halides: Entry into Tetrasubstituted Allenes

“…In the past several years, merging visible light photocatalysis and nickel catalysis has emerged as a powerful tool in organic synthesis. , As part of our continuous effort to pursue radical-mediated sulfonylation of unsaturated hydrocarbons, we hypothesized that addition of the sulfonyl radicals, which are generated in situ from the sulfinate salts using visible light photoredox catalysis, across 1,3-enynes would produce the allenyl radical intermediates, followed by radical binding of the active Ni 0 species and reductive cross-coupling with electrophilic aryl halides to achieve 1,3-enyne difunctionalization.…”

Photoinduced Merging with Copper‐ or Nickel‐Catalyzed 1,4‐Cyanoalkylarylation of 1,3‐Enynes to Access Multiple Functionalizatized Allenes in Batch and Continuous Flow

“…On the basis of the above mechanistic studies and literature precedents, [ 2‐17 ] we propose the photoredox/copper catalytic cycles involve a possible cyanoalkyl radical mechanism in Scheme 4. Initially, the active Ir III species is triggered by the visible light induced and produces the excited photocatalyst * Ir III complex.…”

“…[ 5 ] Compared to these classical approaches, the radical‐mediated 1,4‐difunctionalization of 1,3‐enynes was considered as one of the most straightforward routes to introduce two functional groups simultaneously for the construction of multisubstituted allenes (Scheme 1a). Recently, the groups of Liu, [ 6 ] Wang, [ 7 ] Bao, [ 8 ] Lu, [ 9 ] and Ma [ 10 ] have developed the methods for the 1,4‐difunctionalization of 1,3‐enynes via radical pathway. Despite such breakthroughs, there still exist several long‐standing challenges in this field, e.g ., the low reactivity of the starting materials, the requirement of nucleophiles to terminate the reaction and the difficulty to control 1,2‐ or 1,4‐ radical addition products, which still limit their further development.…”

“…Very recently, the Lu and coworkers presented a photoredox/copper catalysis for the 1,4‐carbocyanations of 1,3‐enynes with alkyl N ‐hydroxyphthalimide esters and trimethylsilyl cyanide (TMSCN). [ 9b ] Later on, the Li's group developed a photoredox/copper catalytic 1,4‐sulfonylarylation of 1,3‐enynes using aryl iodides and sulfinate salts. [ 14 ]…”

Phosphine-catalyzed divergent domino processes between γ-substituted allenoates and carbonyl-activated alkenes

“…In this context, we have keen interest in developing divergent asymmetric synthetic approaches. 25 At the outset, we wanted to examine the domino reaction of γ-substituted allenoates with other carbonyl-activated alkenes. Such structural variation is mechanistically interesting; for instance, the ester-derived enolate will unlikely undergo intramolecular cyclization with another ester moiety and thus offer opportunities for deriving different products.…”