منابع مشابه
The Halogenation of Aromatic Carbinols
In recent years many efforts have been made aiming to define the conditions of the reaction of substitution which lead to inversion of configuration (Walden inversion). The investigations in this direction of Polanyi et al.,’ of Olson,2 of Hughes, Ingold, et aL3 are most outstanding. Polanyi et al. and Olson came to the conclusion that all reactions of substitution by a negative group or ion ar...
متن کاملStructural Perspective on Enzymatic Halogenation
Simple halogen substituents frequently afford key structural features that account for the potency and selectivity of natural products, including antibiotics and hormones. For example, when a single chlorine atom on the antibiotic vancomycin is replaced by hydrogen, the resulting antibacterial activity decreases by up to 70% ( Harris , C. M. ; Kannan , R. ; Kopecka , H. ; Harris , T. M. J. Am. ...
متن کاملManganese Catalyzed C-H Halogenation.
The remarkable aliphatic C-H hydroxylations catalyzed by the heme-containing enzyme, cytochrome P450, have attracted sustained attention for more than four decades. The effectiveness of P450 enzymes as highly selective biocatalysts for a wide range of oxygenation reactions of complex substrates has driven chemists to develop synthetic metalloporphyrin model compounds that mimic P450 reactivity....
متن کاملAllylic halogenation of unsaturated amino acids.
A range of dehydro amino acid derivatives has been prepared and subjected to halogenation using either molecular bromine or chlorine, or NBS. Allylic halogenation of the unsaturated amino acid side chains occurs through radical bromination with NBS. The procedure is complementary to treatment with chlorine, which also affords allyl halides. This latter and unusual reaction is shown through a de...
متن کاملInsights into enzymatic halogenation from computational studies
The halogenases are a group of enzymes that have only come to the fore over the last 10 years thanks to the discovery and characterization of several novel representatives. They have revealed the fascinating variety of distinct chemical mechanisms that nature utilizes to activate halogens and introduce them into organic substrates. Computational studies using a range of approaches have already ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature
سال: 1976
ISSN: 0028-0836,1476-4687
DOI: 10.1038/264488b0