The invention concerns a method for preparing &agr;-halogenated ketones from secondary &agr;-halogenated alcohols. More particularly, the invention concerns the preparation of &agr;-trihalogenated ketones from secondary &agr;-trihalogenated alcohols. The method for preparing said &agr;-halogenated ketone is characterized in that it consists in oxidizing in liquid phase, a secondary &agr;-halogenated alcohol, using molecular oxygen or a gas containing same, in the presence of a catalyst based on a metal M
1
selected among metals of group 1b and 8 of the periodic system of elements and optionally an activating element.
PROCEDE DE PREPARATION DE CETONES ALPHA-HALOGENEES
申请人:RHODIA CHIMIE
公开号:EP1250303A1
公开(公告)日:2002-10-23
[EN] METHOD FOR PREPARING ALPHA-HALOGENATED KETONES<br/>[FR] PROCEDE DE PREPARATION DE CETONES ALPHA-HALOGENEES
申请人:RHODIA CHIMIE SA
公开号:WO2001055067A1
公开(公告)日:2001-08-02
La présente invention a pour objet un procédé de préparation de cétones α-halogènées à partir d'alcools secondaires α-halogénés. L'invention vise plus particulièrement la préparation de cétones α-trihalogénées à partir d'alcools secondaires α-trihalogénés. Le procédé de préparation d'une cétone α-halogénée selon l'invention est caractérisé par le fait qu'il consiste à oxyder en phase liquide, un alcool secondaire α-halogéné, à l'aide d'oxygène moléculaire ou un gaz en contenant, en présence d'un catalyseur à base d'un métal M1 choisi parmi les métaux du groupe 1b et 8 de la classification périodique des éléments et éventuellement d'un activateur.
Regioselective Substitution of Phenols with Trifluoroacetaldehyde Ethyl Hemiacetal
作者:Yuefa Gong、Katsuya Kato、Hiroshi Kimoto
DOI:10.1246/bcsj.74.377
日期:2001.2
Phenol did not react directly with trifluoroacetaldehyde ethyl hemiacetal. In the presence of catalytic amounts of anhydrous potassium carbonate, however, the reaction readily occurred. The p-substituted product 4-(2,2,2-trifluoro-1-hydroxyethyl)phenol predominated. In contrast, the reaction catalyzed by zinc halide predominantly produced the o-substituted product. Corresponding reactions of several
Facile Synthesis of o- and p-(1-Trifluoromethyl)-alkylated Phenols via Generation and Reaction of Quinone Methides
作者:Yuefa Gong、Katsuya Kato
DOI:10.1055/s-2002-20458
日期:——
Several ortho- and para-(1-chloro-2,2,2-trifluoroethyl)phenols were prepared from the corresponding alcohols and thionyl chloride in the presence of pyridine. They reacted smoothly with sodium borohydride and Grignard reagents under mild conditions, forming 2,2,2-trifluoroethyl- or 1-trifluoromethylalkylphenols in high yields.