tert-Butyl Cation Formation in the Hydrolysis of 2-Methyl-2-propanesulfonyl Chloride, the Simplest Tertiary Alkanesulfonyl Chloride
摘要:
Evidence is presented that the only significant reaction of 2-methyl-2-propanesulfonyl chloride (1) (a) in water over the pH range 3.5-13.0 or (b) in methanol-chloroform-d is an ionization to the tert-butyl cation (2) and the chlorosulfite anion (ClSO2-), followed by further reactions of these species. The organic products include isobutylene (3), tert-butyl chloride (4a), tert-butyl alcohol (4b), and, at high pH, 2-methyl-2-propanesulfinate anion (6) and small amounts of 2-methyl-2-propanesulfonate anion (5). In the presence of barium chloride the rate of hydrolysis of 1 is constant over the pH range 3.5-12.0.
Promoting the Hydrosilylation of Benzaldehyde by Using a Dicationic Antimony‐Based Lewis Acid: Evidence for the Double Electrophilic Activation of the Carbonyl Substrate
作者:Masato Hirai、Junsang Cho、François P. Gabbaï
DOI:10.1002/chem.201600971
日期:2016.5.4
The concomitant activation of carbonyl substrates by two Lewisacids has been investigated by using [1,2‐(Ph2MeSb)2C6H4]2+ ([1]2+), an antimony‐based bidentate Lewisacid obtained by methylation of the corresponding distibine. Unlike the simple stibonium cation [Ph3MeSb]+, dication [1]2+ efficiently catalyzes the hydrosilylation of benzaldehyde under mild conditions. The catalytic activity of this