Pseudocyclic bis-N-heterocycle-stabilized iodanes – synthesis, characterization and applications

Abstract

Bis-N-heterocycle-stabilized λ3-iodanes (BNHIs) based on azoles are introduced as novel structural motifs in hypervalent iodine chemistry. A performance test in a variety of benchmark reactions including sulfoxidations and phenol dearomatizations...

Stabilization of Ethynyl‐Substituted Aryl‐λ3‐Iodanes by Tethered N‐Heterocylces**

“…While the alkyne group of the pseudocyclic salt 1 l is nearly in plane with the aromatic system, 2 a is significantly twisted with a C1−I1−N1−C10 dihedral angle of 17.26°. This twist was previously observed for other bis‐ N ‐heterocyclic substituted‐λ 3 ‐iodanes [26] . Additionally, in 2 a 1/6 equiv.…”

“…This twist was previously observed for other bis-N-heterocyclic substituted-λ 3 -iodanes. [26] Additionally, in 2 a 1/6 equiv. of NaOTf is included in the crystal structure (see ESI).…”

Azoiodazinium Salts – Synthesis and Reactivity

“…In contrast to other cyclic iodonium salts, this molecule is nearly in plane with an I1-C1-C15-N4 dihedral angle of 2.03°. [15,17] For the dicationic salt 5av, we observe a coordination of the triflates along the C-I axis with 2.705 Å (I1-O1) and 2.898 Å (I1-O5). For the ortho-methyl-protected analogous 5ax, no halogen bonding to the triflates was observed, indicating an effective steric protection of the σ-holes.…”

“…[10] Our group is interested in the chemistry of hypervalent iodine species in all their variety, particularly those containing N-heterocycles either as tethered stabilizing ligands or as an inclusive part of a cyclic iodonium salt. [11][12][13][14][15][16] We prepared five-membered, N-heterocycle-containing iodoliums 2 and investigated their reactivity and utility in XB-catalysis. We also established onepot methods for generating six-membered carbon-, oxygen-and nitrogen-bridged iodonium salts, such as the iodazinium triflate 3.…”

Synthesis of Mono- and Polyazole Hybrids Based on Polyfluoroflavones

“…In turn, fluorinated flavones offer extra possibilities for their functionalization in reactions with nucleophilic reagents. Fluoroaromatic compounds are well known to be perspective frameworks for their modification by different methods for formation of new C–C and C–heteroatom bonds [ 19 , 20 , 21 ], including C–N bond formation in reactions with azole-type heterocycles [ 22 , 23 , 24 ]. There are known approaches to the synthesis of chromone–azole dyads [ 25 ]; however, data on direct functionalization of fluorine-containing flavones with azoles under S N Ar reaction conditions have only been only in publications from our research team [ 26 , 27 ], although the reaction of nucleophilic aromatic substitution of fluorine atoms is a quite simple, economically and environmentally friendly process, which offers the possibility of substitution for fluorinated substrates with advantages over reactions that use expensive catalysts [ 28 ].…”