vic-Diphosphination of Alkenes with Silylphosphine under Visible-Light-Promoted Photoredox Catalysis

Abstract

An Ir(ppy)-catalyzed vic-diphosphination of styrenes with MeSi-PPh and NFSI proceeds under blue LED irradiation to afford the corresponding bis(diphenylphosphino)ethane derivatives without any formation of hydrophosphination byproducts, which are inevitable and problematic under the previous Cu/NHC catalysis. Additionally, the visible-light-promoted photoredox catalysis enables the diphosphination of relatively challenging aliphatic alkenes and β-substituted styrene.

Bromine Cation Initiated vic-Diphosphination of Styrenes with Diphosphines under Photoredox Catalysis

“…4 Subsequently, a more efficient photoredox catalyst based reaction system with silylphosphine and N-fluorobenzenesulfonimide (NFSI) was developed [Scheme 1 (b)]. 5 However, the second generation catalysis still suffered from narrow functional group compatibility associated with the strong oxidation aptitude of NFSI. Here, we wish to report the third generation catalyst with a combination of photoredox catalysis and bromine cation: an NBS-initiated vic-diphosphination of styrenes with diphosphine under visible-light-promoted Ir(ppy) 3 photoredox catalysis is described [Scheme 1 (c)].…”

“…However, preliminary 31 P{ 1 H} NMR studies with Me 3 Si-PPh 2 and Ph 2 P-PPh 2 showed similar spectra when they were treated with NFSI. 5 Thus, we reinvestigated the reactivity of Ph 2 P-PPh 2 (2a) under Ir(ppy) 3 photoredox catalysis. We consequently found that the care- H NMR yield (entry 5).…”

“…The newly developed protocol is operationally simpler and more efficient than the previously reported diphosphination systems. 4,5 Particularly, much better functional group compatibility is observed. The present photoredox catalysis allows the diphosphine to be adopted in an otherwise challenging diphosphination of alkenes, and enables ligand synthesis 13 from readily available and abundant hydrocarbon materials; this could accelerate the development of newly designed and highly efficient bisphosphine-ligated transition-metal catalysts.…”

Photoinduced Bisphosphination of Alkynes with Phosphorus Interelement Compounds and Its Application to Double-Bond Isomerization

“…The addition of interelement compounds with heteroatom-heteroatom single bonds to carbon-carbon unsaturated bonds has recently attracted wide attention as an atomically efficient method for carbon-heteroatom bond formation [1][2][3][4][5][6]. This addition reaction is promoted by transition-metal catalysts, acids, bases, and radical initiators [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. On the other hand, photoirradiation has recently attracted much attention as a clean, ecofriendly, and powerful method in organic synthesis [27][28][29].…”

Synthesis of DPPP- and DPPPEN-Type Bidentate Ligands by Ring-Opening Diphosphination of Methylene- and Vinylcyclopropanes under Visible-Light-Promoted Photoredox Catalysis

“…Subsequently, the same research group improved the reaction efficiency and scope by using further modified diphosphine monosulfides R 2 P–P­(S)­R 2 and disulfides R 2 (S)­P–P­(S)­R 2 . Our group also focused on the unique reactivity of diphosphines R 2 P–PR 2 under Ir­(ppy) 3 photoredox catalysis and succeeded in the development of diphosphination of alkenes and 1,3-dienes with the assistance of bromine cation additives to provide the corresponding DPPE- and DPPB-type bidentate ligands ( n = 2, 4 in Figure ), respectively (Scheme b, left) . However, the synthesis of 1, n -bis­(diphenylphosphino)­alkanes with the odd-numbered methylene tethers, namely, DPPP- and DPPPEN-type ligands ( n = 3, 5 in Figure ) still remains unexplored.…”