Poly[styrene(iodosodiacetate)]-Promoted Ring Expansion Reaction of 1-Alkynylcycloalkanols: A Novel Synthesis of (<i>Z</i>)-2-(1-Iodo-1-organyl)methylenecycloalkanones
作者:Xian Huang、Jiang-Min Chen
DOI:10.1055/s-2004-831214
日期:——
The ringexpansion reaction of 1-alkynylcycloalkanols with poly[styrene(iodosodiacetate)] and iodine affords (Z)-2-(1-iodo-1-organyl)methylenecycloalkanones in moderate to good yields.
Catalytic alkynylation of diverse ketones and aldehydes using nonmetallic benzyltrimethylammonium hydroxide or a basic resin of the hydroxide type in DMSO is described. Aliphatic or alicyclic carbonyl partners gave satisfactory results, whereas aromatic ones afforded products with low yields. When aromatic aldehydes were reacted with phenylacetylene, enones such as chalcone derivatives were obtained in place of ynols. These organobase-catalyzed systems provide a practical nonmetallic protocol for C-C bond formation.
Synthesis of 4-Oxoisoxazoline <i>N</i>-Oxides via Pd-Catalyzed Cyclization of Propargylic Alcohols with <i>tert</i>-Butyl Nitrite
A cyclization of propargylicalcohols with tert-butyl nitrite at room temperature in air was achieved using Pd(OAc)2 as catalyst. The first reported 4-oxoisoxazoline N-oxides could be directly accessed from a range of multisubstituted propargylicalcohols in moderate to excellent yields under mild conditions. Density functional theory calculations indicated that the reaction proceeds through a palladium-catalyzed