The Chemistry between Hypervalent Iodine(III) Reagents and Organophosphorus Compounds

Abstract

The intersection between the chemistries of hypervalent iodine (HVI) reagents and organophosphorus compounds holds significant potential. To date, the merging of these research spheres has led to novel iodane motifs, many of which have been used in new oxyphosphorylation methodologies. In addition, HVI reagents have proven easily capable of transferring electrophilic carbon-based (alkyl, aryl, al-kynyl, etc.) ligands to various phosphorus nucleophiles. Furthermore, the ease with which HVI reagents oxidize phosphorus has led to novel esterification, amidation, alcohol functionalization and peptide coupling reactions. This Focus Review summarizes the chemistry to-date between these two important classes of compounds. Scheme 1. General reactivity modes of l 3 -iodanes.[a] Dr.Scheme 2. Phosphorus-containing HVI reagents.Scheme 3. ortho-Stabilized HVI reagents. Scheme 4. Phosphorus-containing HVI reagents generated in situ. Scheme 5. Synthesis of alkynyl phosphate esters. Scheme 6. Oxyphosphorylation of vinyliodonium salts. Scheme 10. Synthesis of a-carbonyl phosphonates and phosphinates. Scheme 11. Synthesis of a-carbonyl phosphonates. Scheme 12. Synthesis of a-carbonyl phosphonates via in situ-generated 26. Scheme 13. Synthesis of tris-ketol phosphates. Scheme 19. Phosphorylation of silylenol ethers. Scheme 20. Preparation of phosphonates by arylation of phosphites. Scheme 21. Arylation of PÀH phosphine oxides and phosphonates. Scheme 22. Synthesis of bis(triphenylphosphonium) salts. Scheme 23. Phosphorylation of alkynyliodonium salts with phosphites. Scheme 28. Synthesis of vinyl phosphonates from vinyl iodonium salts. Scheme 30. Trifluoromethylation of naphthyl-derived phosphines. Scheme 29. Trifluoromethylation of phosphines. Scheme 35. Peptide coupling mediated by PPh 3 and 200 or 217.Scheme 36. Synthesis of acyl and alkyl chlorides, and alkyl fluorides using 207 and 208 generated in situ.Scheme 37. Synthesis of mixed iodonium phosphonium ylides.

A Continuum from Halogen Bonds to Covalent Bonds: Where Do λ3 Iodanes Fit?

“…Hypervalent iodine compounds (HVI) are important alternatives to transition metal reagents because of their reactivity, synthetic utility, low cost, abundance, and non-toxic nature [1][2][3][4][5][6]. HVIs are involved in a multitude of reactions such as: reductive elimination, ligand exchange, oxidative addition, and ligand coupling [7,8]. The three-center four-electron bonds (3c-4e) in HVI are weak and polarizable, which is valuable in synthetic organic chemistry, as they can exchange leaving groups or accept electrophilic/nucleophilic ligands depending on their surroundings [9].…”

DFT Mechanistic Investigation into BF3-Catalyzed Alcohol Oxidation by a Hypervalent Iodine(III) Compound

“…Hypervalent iodine­(III) compounds have attracted much attention as oxidants in organic synthesis, as they can be a replacement for transition metals with the advantage of having environmentally benign properties. − Although iodine­(III) reagents are competent to conduct many organic transformations, addition of a Lewis acid such as BF 3 is often a prerequisite for a process to occur. For example, it has been shown that an iodine­(III) reagent in conjunction with BF 3 ·Et 2 O considerably accelerates the processes that yield λ 3 -diaryliodanes, olefin diacetoxylation, and a plethora of other products. − In this context, Ochiai et al reported that alcohols can be selectively oxidized by hypervalent iodine­(III) compound 2 to aldehydes or ketones in the presence of BF 3 ·Et 2 O as the catalyst (Scheme ).…”

Synthesis of Diverse Aryliodine(III) Reagents by Anodic Oxidation†

“…Table 3 Anodic oxidation for the synthesis of diaryliodonium salts Moreover, to demonstrate the efficacy of this electrochemical process for the anodic oxidation synthesis of diverse hypervalent iodine(III) reagents, we showed that simple iodobenzene can be efficiently transferred into phenyliodine diacetate (PIDA) under mild electrochemical conditions (Scheme 2). Further treatment with some common reagents led to the facile ligand exchange, derivatizing a variety of useful hypervalent iodine(III) reagents in good to excellent yields with high selectivity, including [hydroxy-(phosphoryloxy)iodo] benzene 5, [14] Koser's reagent (6), [15] amidoiodane 7, [16] iodonium imide 8, [17] alkynyliodonium salt (9), [18] aryliodonium ylide 10, [19] and Weiss' reagent 11, [20] which all find numerous applications in various bond-forming reactions. Furthermore, a range of important benziodoxole reagents containing useful OMe 12, OAc 13, CN 14, and acetylene (15) groups could be obtained in good to high yields via the ligand exchange from crude hydroxy benziodoxolone 2p (Scheme 3).…”