Reactions of ortho-substituted α,α-dibromoacetophenones with nucleophiles: first examples of combined carbophilic and bromophilic attack on C–Br bonds
摘要:
An efficient method for the formation of alpha-carbonyl-monosubstituted acetophenones from ortho-methoxy-and ortho-hydroxy-alpha,alpha-dibromoacetopheiiones and a range of selected nucleophiles, occurring via a carbophilic substitution/bromophilic substitution/protonation cascade process, is described. In turn, the preparation of alpha,alpha-dibromoacetophenones, isolated in high yields, relies on the neighboring group participation of the ortho-substituents in the starting ortho-substituted acetophenones. (C) 2008 Elsevier Ltd. All rights reserved
In Situ–Generated Zinc Bromide–Catalyzed α‐Bromination of Alkanones in Water
作者:Satinder K. Juneja、Deepak Choudhary、Satya Paul、Rajive Gupta
DOI:10.1080/00397910600770714
日期:2006.9.1
Abstract α‐Bromination of alkanones with bromine catalyzed by in situ–generated zinc bromide from zinc dust and bromine in water is investigated. Bromination with dioxane‐dibromide as a source of bromine does not require zinc dust and provides selectively α‐mono and α,α‐dibromo products in excellent yields when water is used as solvent.
Regioselective Bromination of Organic Substrates by Tetrabutylammonium Bromide Promoted by V<sub>2</sub>O<sub>5</sub>−H<sub>2</sub>O<sub>2</sub>: An Environmentally Favorable Synthetic Protocol
作者:Upasana Bora、Gopal Bose、Mihir K. Chaudhuri、Siddhartha S. Dhar、Rangam Gopinath、Abu T. Khan、Bhisma K. Patel
DOI:10.1021/ol9902935
日期:2000.2.1
[reaction: see text] Vanadium pentoxide very effectively promotes the bromination of organicsubstrates, including selective bromination of some aromatics, by tetrabutylammonium bromide in the presence of hydrogen peroxide; mild conditions, high selectivity, yield, and reaction rate, and redundancy of bromine and hydrobromic acid are some of the major advantages of the synthetic protocol.
[EN] POLYMERIZATION OF OLEFINS<br/>[FR] POLYMERISATION D'OLEFINES
申请人:E.I. DU PONT DE NEMOURS AND COMPANY
公开号:WO1998030609A1
公开(公告)日:1998-07-16
(EN) Selected olefins such as ethylene and $g(a)-olefins are polymerized by nickel [II] complexes of certain monoanionic ligands. The polyolefins are useful in many applications such as molding resins, film, fibers and others. Also described are many novel nickel compounds and their precursors, as well as novel ligands.(FR) L'invention concerne des oléfines sélectionnées, telles que l'éthylène et les $g(a)-oléfines, polymérisées par des complexes au nickel [II] de certains ligands mono-anioniques. Ces polyoléfines sont utiles dans de nombreux domaines d'application, notamment dans les résines à mouler, les films et les fibres. L'invention concerne également de nombreux composés de nickel nouveaux et leurs précurseurs, ainsi que de nouveaux ligands.
Reactions of ortho-substituted α,α-dibromoacetophenones with nucleophiles: first examples of combined carbophilic and bromophilic attack on C–Br bonds
An efficient method for the formation of alpha-carbonyl-monosubstituted acetophenones from ortho-methoxy-and ortho-hydroxy-alpha,alpha-dibromoacetopheiiones and a range of selected nucleophiles, occurring via a carbophilic substitution/bromophilic substitution/protonation cascade process, is described. In turn, the preparation of alpha,alpha-dibromoacetophenones, isolated in high yields, relies on the neighboring group participation of the ortho-substituents in the starting ortho-substituted acetophenones. (C) 2008 Elsevier Ltd. All rights reserved