Heteroatom Chemistry
Volume 19, Number 1, 2008
LiClO Catalyzed Mild and Efficient Method
4
for the Synthesis of Thiiranes from Oxiranes
Ch. Sanjeeva Reddy and S. Nagavani
Department of Chemistry, Kakatiya University, Warangal 506 009, India
Received 26 June 2006; revised 26 October 2006
tions and is shown to enhance reaction rates [5]. Or-
ABSTRACT: Oxiranes are efficiently converted to
ganic solutions of lithium perchlorate provide a con-
venient reaction medium to perform the reactions
under neutral conditions. Potassium thiocyanate is
a transfer agent for sulfur, commonly used in the thi-
iranes synthesis from epoxides. Now, we have found
that potassium thiocyanate reacts with oxiranes, in
the presence of catalytic amount of lithium perchlo-
rate in the nonaqueous solvent acetonitrile under
mild conditions, to form the corresponding thiiranes
in excellent yield. In this report, we describe the
synthesis of thiiranes from oxiranes using lithium
perchlorate.
the corresponding thiiranes by potassium thiocyanate
in the presence of catalytic amounts of LiClO4 with
excellent yields under mild and nonaqueous condi-
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C
tions.
2008 Wiley Periodicals, Inc. Heteroatom Chem
19:97–99, 2008; Published online in Wiley InterScience
(www.interscience.wiley.com). DOI 10.1002/hc.20376
INTRODUCTION
Organic sulfur compounds have become increas-
ingly useful and important in organic synthesis. Thi-
iranes are sulfur heterocycles and are used in the
pharmaceutical, polymer, pesticide, and herbicide
industries [1]. Particularly, thiiranes have played an
important role in various synthetic transformations
[2]. Epoxides are the most convenient starting ma-
terials for preparation of simple thiiranes because
of their ease of formation, wide reactivity, and abil-
ity to undergo regioselective ring-opening reactions,
contributing largely to their synthetic value [3]. A
variety of methods have been reported to produce
thiiranes from oxiranes [4]. Many of these proce-
dures involve extended reaction times, use of expen-
sive reagents, and high-temperature reaction condi-
tions. Therefore, there is still a scope to find potential
alternative procedures, especially low cost, low toxic,
and operable under mild conditions that are in high
demand. In this regard, LiClO4 is used as a mild
Lewis acid catalyst in various organic transforma-
RESULTS AND DISCUSSION
The reaction was carried out by adding lithium per-
chlorate to a mixture of styrene oxide and potassium
thiocyanate in acetonitrile at room temperature.
After the mixture was stirred at room temperature
for 1-2 h, TLC showed the disappearance of start-
ing materials. After work up, the crude product was
subjected to column chromatography over silicagel
and provided the product in 90% yield. By the spec-
troscopic data, the product was confirmed as 2a and
was compared with the literature data (Scheme 1).
Similarly, a wide range of epoxides reacted
smoothly with KSCN under similar conditions, giv-
ing the products in good yield ranging from 80 to
Correspondence to: Ch. Sanjeeva Reddy; e-mail: chsrkuc@
yahoo.co.in.
2008 Wiley Periodicals, Inc.
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