Methyl N-(triethylammoniumsulfonyl)carbamate, also known as Burgess regent, is a mild yet powerful dehydrating agent.
Usefulness of the regent in various synthetic transformations and in the synthesis of various heterocyclic systems has
Methyl N-(triethylammoniumsulphonyl)carbamate (1), also known as Burgess reagent,
is a mild and selective dehydrating agent, and can be successfully utilized for the preparation of alkenes
from alcohols. However, it went into oblivion for nearly a decade soon after its discovery by E. M.
Burgess in 1968. It was Peter Wipf who brought it to the attention of organic chemists through its
extensive use in the formation of 5-membered heterocycles from their acyclic precursors. An
interesting feature of this reagent is that the dehydration is a pyrolytic reaction which can be
effected below 100°C. The reagent is highly soluble in most of the common organic solvents
including nonpolar ones, even though it is formulated as a salt. The dehydration takes place through
a variant of Ei mechanism resulting in syn-elimination. The reagent is also known to bring about
many important transformations such as preparation of isocyanides, nitriles, and nitrile oxides
from formamides, primary amides and nitroalkanes, respectively. The most noteworthy application has been in the cyclodehydration of hydroxy amides and thioamides to afford the corresponding heterocycles. Because of the mild conditions required as well as the selectivity observed, the
reagent has received wide acceptance in natural product synthesis. It is intended in this review to
give an updated overview of the reagent.
The Burgess reagent or methyl N-(triethylammoniumsulfonyl)carbamate was developed in the laboratory of Edward M. Burgess at Georgia Tech. It is a mild and selective dehydrating reagent often used in organic chemistry. It is used to convert secondary and tertiary alcoholwith an adjacent proton into alkenes. Primary alcohols do not work well. The reagent is soluble in common organic solvents and alcohol dehydration takes place with syn elimination. The Burgess reagent is a carbamate and a so-called inner salt. A general mechanism is shown below.
The reagent is prepared from chlorosulfonylisocyanate by reaction with subsequent treatment with methanol and triethylamine in benzene:
read m0re on
a full lenght paper
site for reagents used in organic synthesis, part of main page shown below
PAGE CREATED BY DR ANTHONY MELVIN CRASTO M.SC, Ph.D (ORGANIC CHEMISTRY,24+ years experience in the field of research and development, currently with Glenmark, Mumbai India
Ентоні 安东尼 แอนโทนี Энтони אַנטאַני Антхони एंथनी 안토니
View Larger Map GLENMARK RESEARCH CENTRE
MY RESEARCH CENTRE AT NAVI MUMBAI INDIA