Studies on the catalysis of the reaction of organotin phenoxides with bis(2,2,2‐trichloroethyl) azodicarboxylate by lithium perchlorate

Abstract

Organotin phenoxides, which are distinctly more active than the corresponding phenols, react at room temperature with bis(2,2,2-trichloroethyl) azodicarboxylate to produce para-substituted phenolic hydrazides in high yields.

Perchloric Acid and Its Salts: Very Powerful Catalysts in Organic Chemistry

“…The reaction might be extended to phenols. 152 Phenols do not react with azodicarboxylates under these conditions, but the use of O-metalation to enhance the rate of electrophilic substitution in the ring is a familiar process. Indeed the reactions occur equally with 10 mol % of tributyltin oxide thus avoiding the need to prepare quantitatively the tin phenoxide.…”

“…For example, Cu(CH 3 CN) 4 ClO 4 and the planar chiral P,Sligand 1-(diphenylphosphino)-2-(t-butylthio)ferrocene (0.5-3 mol %), afforded the endo adducts with up to 97% yield and 99% ee. Moreover the combination of Ni(ClO 4 ) 2 • 6H 2 O and chiral binaphthyldiimine ligand (66) with cyclic azomethyne imines (152) and 60 leads to fused 153 with up to 93% yield and 97% ee, 297 while simple azomethyne ylides and N-arylmaleimides provide up to 92% yield and 91% ee (Scheme 102). 298 The Cu(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethyne ylides to nitroalkenes shows an interesting behavior.…”

Catalysis of reactions of allyltin compounds and organotin phenoxides by lithium perchlorate

“…However, it is known that heating of solution of LiClO 4 in Et 2 O or acetone may be hazardous. We wanted to prove that the use of organotin phenoxides instead of pure phenols and more concentrated solution of LiClO 4 would enable to carry out reactions with bis(trichloroethyl) azodicarboxylate with quantitative yield at room temperature (see Table 9) [29]. We have compared the yields of the reactions of five phenols and obtained from them tributytyltin phenoxides in 5 mol dm À3 solutions of LiClO hydrazides prepared during this study were easily converted to their corresponding anilines by reduction with zinc dust in acetic acid.…”

Studies on the Catalysis by Lithium Perchlorate of Reactions of Aromatic Amines with Diethyl Azodicarboxylate and Naphtalen-2-ol with 4-phenyl-1,2,4-triazoline-3,5-dione

“…Polanc [3] demonstrated the variety of applications of arylhydrazines in organic synthesis. Recently we have shown that organotin phenoxides react at room temperature with diethyl azodicarboxylate [4] and bis(2,2,2-trichloroethyl) azodicarboxylate [5] in diethyl ether, in the presence of lithium perchlorate, give the corresponding ring-aminated phenols in excellent yield. Also the analogous catalytic effect of LiClO 4 (typically, 5 M solutions in diethyl ether) has been observed by us for ene and metalloene reactions of diethyl azodicarboxylate and 4-phenyl-1,2,4-trizoline-3,5-dione [6].…”