Deprotection of Acetals and Silyl Ethers Using a Polymer-Supported π-Acid Catalyst: Chemoselectivity and Polymer Effect
作者:Nobuyuki Tanaka、Yukio Masaki
DOI:10.1055/s-1999-3000
日期:1999.12
A polymeric dicyanoketene acetal (DCKA), prepared from a styrene monomer bearing dicyanoketene acetal functionality, was found to be an effective and recyclable catalyst in the chemoselective deprotection of acetals and silyl ethers. A remarkable acceleration accountable for the polymer effect was observed.
Vicinal Bisheterocyclizations of Alkynes via Nucleophilic Interception of a Catalytic Platinum Carbene
作者:Paul A. Allegretti、Eric M. Ferreira
DOI:10.1021/ja408957a
日期:2013.11.20
ethers is described. The transformation exploits the intermediacy of a key α,β-unsaturated carbene. The reactivity of this carbene is such that systems can be developed which avoid a complicating 1,2-hydrogen migration, allowing remarkable versatility in the selective syntheses of oxygen- and nitrogen-containing vicinal bis-heterocyclic compounds.