Phosphine Organocatalysis

Abstract

The hallmark of nucleophilic phosphine catalysis is the initial nucleophilic addition of a phosphine to an electrophilic starting material, producing a reactive zwitterionic intermediate, generally under mild conditions. In this Review, we classify nucleophilic phosphine catalysis reactions in terms of their electrophilic components. In the majority of cases, these electrophiles possess carbon–carbon multiple bonds: alkenes (section 2), allenes (section 3), alkynes (section 4), and Morita–Baylis–Hillman (MBH) alcohol derivatives (MBHADs; section 5). Within each of these sections, the reactions are compiled based on the nature of the second starting material—nucleophiles, dinucleophiles, electrophiles, and electrophile–nucleophiles. Nucleophilic phosphine catalysis reactions that occur via the initial addition to starting materials that do not possess carbon–carbon multiple bonds are collated in section 6. Although not catalytic in the phosphine, the formation of ylides through the nucleophilic addition of phosphines to carbon–carbon multiple bond–containing compounds is intimately related to the catalysis and is discussed in section 7. Finally, section 8 compiles miscellaneous topics, including annulations of the Hüisgen zwitterion, phosphine-mediated reductions, iminophosphorane organocatalysis, and catalytic variants of classical phosphine oxide–generating reactions.

Pyridinylidenaminophosphines: Facile Access to Highly Electron‐Rich Phosphines

“…Tertiary phosphines are unique and diverse Lewis bases that are widely used in many areas of synthetic chemistry. Applications range from their utilization as ubiquitous ligands in coordination or organometallic chemistry to phosphine‐catalyzed and stoichiometric phosphine‐mediated transformations. One of the main reasons for their broad range of applications is the intriguing ease with which the steric and electronic properties of phosphines can be rationally tuned using various substituents .…”

The Game of Electrons: Organocatalytic Higher‐Order Cycloadditions Involving Fulvene‐ and Tropone‐Derived Systems

“…The remarkable ability of phosphines to act as nucleophilic catalysts of many different organocatalytic transformations is well‐recognized . Historically, this activation mode has been utilized to develop new organocatalytic higher‐order cycloadditions with the participation of tropone‐derived systems as higherenes for the first time.…”

Organophosphorus‐Catalyzed Deoxygenation of Sulfonyl Chlorides: Electrophilic (Fluoroalkyl)sulfenylation by PIII/PV=O Redox Cycling

“…[5] In this vein, recent work by the groups of Shibata and Cahard, [6] Liu, [7] and Zhao [8] reflects the synthetic potential of this approach by the use of phosphorus derivatives as oxygen acceptors,a llowing access to valuable and reactive sulfenyl electrophiles from the more readily handled sulfonyl congener. [10,11] In this context, we have shown that af our-membered phospha-Figure 1. These undesirable characteristics are exacerbated by the fact that the P III reagent, itself ap otent nucleophile,c onsumes the electrophilic sulfenyl donor in competition with the target substrate to give undesired thiophosphonium ions ( Figure 1B).…”

“…[10,11] In this context, we have shown that af our-membered phospha-Figure 1. [10,11] In this context, we have shown that af our-membered phospha-Figure 1.…”

“…[10,11] In this context, we have shown that af our-membered phospha-cycloalkane (i.e., the phosphetane 2,T able 1) in combination with ah ydrosilane terminal reductant provides an efficient organocatalytic platform for OATreactions.Such aphosphacatalytic system has been shown to promote efficient reductive OATf rom carbonyl [12] and nitro groups [13] by cycling in the P III /P V =Or edox couple to reveal carbon-and nitrogenbased reactive intermediates,r espectively.W ee nvisioned advancing this biphilic organophosphorus-catalyzed OAT concept to encompass deoxygenative processing of sulfonyl moieties to furnish reactive sulfur(II)-based electrophilic intermediates. [10,11] In this context, we have shown that af our-membered phospha-cycloalkane (i.e., the phosphetane 2,T able 1) in combination with ah ydrosilane terminal reductant provides an efficient organocatalytic platform for OATreactions.Such aphosphacatalytic system has been shown to promote efficient reductive OATf rom carbonyl [12] and nitro groups [13] by cycling in the P III /P V =Or edox couple to reveal carbon-and nitrogenbased reactive intermediates,r espectively.W ee nvisioned advancing this biphilic organophosphorus-catalyzed OAT concept to encompass deoxygenative processing of sulfonyl moieties to furnish reactive sulfur(II)-based electrophilic intermediates.…”