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Organotin Perfluorooctanesulfonates as Air‐Stable Lewis Acid Catalysts: Synthesis, Characterization, and Catalysis
Author(s) -
An De Lie,
Peng Zhihong,
Orita Akihiro,
Kurita Akinobu,
Mane Sumiyo,
Ohkubo Kei,
Li Xingshu,
Fukuzumi Shunichi,
Otera Junzo
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200501091
Subject(s) - chemistry , catalysis , aldol reaction , solubility , ionic bonding , lewis acids and bases , dissociation (chemistry) , inorganic chemistry , organic chemistry , lewis acid catalysis , hydrolysis , ion
Abstract The reactions of 1,3‐dichloro‐1,1,3,3‐tetrabutyldistannoxane and dialkyltin dihalides with silver perfluorooctanesulfonate provided the corresponding sulfonates as hydrates. The number of water molecules ( n ) of hydration was dependent on the conditions. The distannoxane derivative was identified as n from 0.5 to 6, while in the hydrated mononuclear species and DMSO complexes n varied widely from 4 to 13. 119 Sn NMR spectroscopy and conductivity measurements indicated the ionic dissociation of these compounds in solution. These compounds exhibited unusually high solubility in polar organic solvents. The ionic dissociation together with facile hydration probably causes the unusual solubility. The Lewis acidity of these compounds was found to be high among organotin derivatives on the basis of ESR spectra of superoxide/metal‐ion complexes. In contrast to well‐known organotin triflates, these compounds suffered no hydrolysis upon storage in open air. The high catalytic activity of the distannoxane 1 was exemplified for various carbon–carbon bond‐forming reactions, such as Mukaiyama–aldol as well as ‐Michael reactions and allylation of aldehydes.