74663-55-1Relevant academic research and scientific papers
Rhodium-catalyzed [2+2+1+1] cyclocarbonylative coupling of alkynes with carbon monoxide affording tetrasubstituted p-benzoquinones
Huang, Qiufeng,Hua, Ruimao
, p. 8333 - 8337 (2007)
In this strategy, the tetrasubstituted benzoquinones have been prepared directly by a [2+2+1+1] cyclocarbonylative coupling reaction of internal alkynes with CO in the presence of [RhCl(CO)2]2. The low concentration of CO in the reaction is the crucial point for the chemoselective formation of tetrasubstituted benzoquinones in good to high yields. Functional groups such as chloro, methoxy, cyano, vinyl, fluoro, and carboxylate are tolerated under the reaction conditions.
Alumina-Catalyzed Reactions of Hydroxyarenes and Hydroaromatic Ketones. 9. Reaction of Phenol with 1-Propanol
Klemm, LeRoy H.,Taylor, Dennis R.
, p. 4320 - 4326 (2007/10/02)
At 250-350 deg C in the presence of alumina, phenol (1) reacts with excess 1-propanol to give mainly (>90percent) C-alkylation to form mono- to penta-n-propylphenols plus some O-alkylations to form n-propyl aryl ethers. The principal component of the product mixture from 1 is 2,6-di-n-propylphenol (26-50 mol percent yield). With 4-n-propylphenol as substrate (instead of 1), tri-, tetra-, and penta-n-propylphenols are formed in 48-79percent combined yield. On the average, only 3percent of the total C3H7 groups in the product mixture are isopropyl ones. Deoxygenation is not observed. It is proposed that the principal products result from an SN2-type reaction mechanism which involves nucleophilic attack (variously by C-2, C-4, C-6, or O) of an adsorbed ambident phenoxide ion onto C-1 of an adsorbed n-propoxide group. n-Propylation at C-3 and C-5 of the phenol ring results from surface-catalyzed dienone-phenol rearrangement.Isopropylation may occur via a side reaction of SN1 type.
