Use of Organobismuth Derivatives for Arylation of Piperazines

Abstract

This communication presents the synthesis of N-phenylpiperazines (4), using the organobismuth compound (3) as avlating agent. Triarylbismuthine (3) was obtained by condensation of dty BiCl3 with the orpnolithium intermediate (2).

Modern Synthetic Methods for Copper‐Mediated C(aryl)O, C(aryl)N, and C(aryl)S Bond Formation

“…[113] A range of heterocyclic (Scheme 102) and nonheterocyclic (Scheme 103) products were formed under these standard conditions. [17,[114][115][116][117][118][119][120][121][122][123][124][125][126][127][128] These substrates were, in general, the first true exploration of the substrate scope of copper-catalyzed heteroatom-arylation reactions, as can be witnessed in the similarity between the schemes in earlier sections.…”

Organobismuth Reagents: Synthesis, Properties and Applications in Organic Synthesis

“…51 Triarylbismuthines can also be prepared via the addition of organolithium reagents over inorganic bismuth salts (Step 14b). Using this approach, {2,4,6-tris(trifluoromethyl)phenyl}bismuth, 52 tris{2,4,6-(triphenyl)phenyl}bismuth, 53 tris(cyclohexylidene-2,3-dioxyphenyl)bismuthine, 54 tris(4dimethylaminophenyl)bismuth, 55 tris(4-nitrophenyl)bismuth 56 and tris(heteroaryl)bismuths 57 derived from furan and pyrrole were efficiently prepared from the corresponding organolithium reagents. The synthesis of a phosphorescent triarylbismuth compound derived from 1-bromo-4-(N-7-azaindolyl)benzene, which can be used in arylation reactions to label molecules, was also accomplished by Wang using this approach.…”

A facile and practical copper diacetate mediated, ligand free C–N cross coupling of trivalent organobismuth compounds with amines and N-heteroarenes

“…Various hydrazine derivatives were studied with respect to arylation by triarylbismuthane and triarylbismuth diacetate reagents with emphasis on scope and limitations by Tsubrik et al 24 Among these reagents, a few contained bulky substituents in their aromatic rings and substrates spanned a range from simple hydrazides to triply protected hydrazines. Organobismuth derivatives of pyrocatechol fragment for arylation of piperazines using copper acetate as catalyst in DCM was reported by Vassileva et al 25 which was used to synthesize eltoprazine [l-(2,3-dihydro-1,4-benzodioxine-5-yl)-piperazine] a potential anxiolytic and antidepressant drug. Recently copper-catalyzed coupling reaction between alkynyl (triaryl)bismuthonium salts and ve-membered imides was reported by Sueda et al 26 which was utilized to synthesize 4-amino-1,2,3-triazole.…”