Studies on the Catalysis of the Reaction of Organotin Phenoxides with Diethyl Acetylenedicarboxylate.

Abstract

Phenol ethers Q 0270Studies on the Catalysis of the Reaction of Organotin Phenoxides with Diethyl Acetylenedicarboxylate. -In the presence of LiClO4, tinphenoxides (V) and diester (II) give mixtures of phenyl vinyl ethers and o-vinylphenol derivatives. In the case of 2,6-disubstituted tinphenoxide (I) only phenol ethers are formed. -(KINART*, W.; KINART, C. M.; TRAN, Q. T.; OSZCZEDA, R.; Appl. Organomet. Chem. 19 (2005) 1, 147-152; Dep. Org. Chem., Univ. Lodz, PL-90-136 Lodz, Pol.; Eng.) -Klein 25-073

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

“…In fact, the reaction usually gives pairs of ortho-substituted vinylphenols and phenyl vinyl ethers, but for the reaction of tributyl-(2,6-dimethoxyphenoxy)tin, only the formation of ethers is observed. 154 It is worth noting that exclusively tin phenoxides can give ring alkylated products (in fact sodium phenoxides give only phenyl vinyl ethers) supporting evidence of a stabilization of tin in the intermediate by coordination to anionic centers. 155 Different Lewis acids are able to promote the Friedel-Crafts reaction between 5-bromohydantoin (76) and aromatic compounds to give 5-arylhydantoins (Scheme 50), important intermediates in the enzymatic production of (R)-2-arylglycines.…”

“…On the other hand, diethyl acetylenedicarboxylate seems to follow the metalloene mechanism, because only products from vinylation in the ortho position are recovered. In fact, the reaction usually gives pairs of ortho -substituted vinylphenols and phenyl vinyl ethers, but for the reaction of tributyl-(2,6-dimethoxyphenoxy)tin, only the formation of ethers is observed . It is worth noting that exclusively tin phenoxides can give ring alkylated products (in fact sodium phenoxides give only phenyl vinyl ethers) supporting evidence of a stabilization of tin in the intermediate by coordination to anionic centers …”

“…298 The Cu(I)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethyne ylides to nitroalkenes shows an interesting behavior. First the use of a weak base such as NEt 3 leads to a stepwise mechanism where the pyrrolidine derivatives (154) are obtained with high ee, but in moderate yields owing to Michael addition to 155, which occurs as a side reaction (Scheme 103).…”

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

“…Recently, Strazisar and Wolczanski [34] studied the possibility of application of vinyl ethers (including phenyl vinyl ethers) for production of commercially important polymers generated using single-site Ziegler-Natta catalysts. Due to the importance of both vinylphenols and phenyl vinyl ethers, we have decided to apply the analogous as previously strategy used for amination of phenols in purpose of their vinylation [35]. The tributyltin phenoxides and diethyl acetylenedicarboxylate were added to 5 mol dm À3 solutions of LiClO 4 in diethyl ether at 298 K. They were stored at room temperature for 2 days.…”