Catalytic Enantioselective Conversion of Epoxides to Thiiranes
作者:Saihu Liao、Markus Leutzsch、Mattia Riccardo Monaco、Benjamin List
DOI:10.1021/jacs.6b01960
日期:2016.4.27
A highlyefficient and enantioselective Brønsted acid catalyzed conversion of epoxides to thiiranes has been developed. The reaction proceeds in a kineticresolution, furnishing both epoxide and thiirane in highyields and enantiomeric purity. Heterodimer formation between the catalyst and sulfur donor affords an effective way to prevent catalyst decomposition and enables catalyst loadings as low as
Reaction of Optically Active Oxiranes with Thiofenchone and 1-Methylpyrrolidine-2-thione: Formation of 1,3-Oxathiolanes and Thiiranes
作者:Changchun Fu、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.201100043
日期:2011.5
of the configuration (Scheme 4). The analogous reaction of 14a with (R)‐2‐[(triphenylmethyl)oxy]methyl}oxirane ((R)‐16b) led to the corresponding (R)‐configured thiirane (R)‐17b (Scheme 5); its structure and configuration were also determined by X‐ray crystallography. A mechanism via initial ring opening by attack at C(3) of the alkyl‐substituted oxirane, with retention of the configuration, and subsequent
SnCl 4催化(-)-硫代孕酮(= 1,3,3-三甲基双环[2.2.1]庚烷-2-硫酮; 10)与(R)-2-苯基环氧乙烷((R)-11)的反应无水CH 2 Cl 2在-60°下通过区域选择性环扩大反应生成两个螺环,立体异构的4-苯基-1,3-氧杂硫杂环戊烷12和13 ,这是根据先前报道的环氧乙烷与硫酮的反应(方案3)得出的。主要异构体12的结构和构型是通过X射线晶体学确定的。另一方面,1-甲基吡咯烷-2-硫酮(14a)(R)-11立体选择性地产生(S)-2-苯基噻吩烷((S)-15),产率为56%,ee为87-93%,再加上1-甲基吡咯烷酮-2-酮(14b)。这种转变是通过在芳基取代的环氧乙烷的C(2)处S原子的S N 2型攻击而发生的,因此,会发生构型反转(方案4)。14a与(R)-2-([((三苯甲基)氧基]甲基}环氧乙烷((R)-16b)的类似反应产生相应的(R)配置的硫杂环丁烷(R)‐
Conversion of Epoxides to Thiiranes with Thiourea or Ammonium Thiocyanate Catalyzed with Poly(4-Vinyl Pyridine)-Ce(OTf)<sub>4</sub>
作者:N. Iranpoor、B. Tammi、M. Shekarriz
DOI:10.1080/00397919908085959
日期:1999.10
Abstract Conversion of epoxides to thiiranes with ammonium thiocyanate or thiourea in the presence of poly(4-vinyl pyridine)-Ce(OTf)4 as catalyst and under non-aqueous condition is reported. Stereospecific conversion of R-(+)-styrene oxide to S-(-)-styrene sulfide was achieved in high optical purity. The polymer can be easily reloaded.
A Green Protocol for the Easy Synthesis of Thiiranes from Epoxides Using Thiourea/Silica Gel in the Absence of Solvent
作者:Nasser Iranpoor、Habib Firouzabadi、Abbas Ali Jafari
DOI:10.1080/104265090889404
日期:2005.8.1
The use of thiourea/silica gel provides a green protocol for the easy and high-yielding preparation of thiiranes from different classes of epoxides in the absence of solvent at room temperature. The high stereospecific conversion of (R)(+)-styrene oxide to (S)(+)-styrene sulfide is also reported using this reagent system.
Stereospecific formation of S(−) styrene sulfide: Efficient conversion of epoxides to thiiranes catalysed with Ru(III)
作者:Nasser Iranpoor、Foad Kazemi
DOI:10.1016/s0040-4020(97)00719-9
日期:1997.8
Ru(III) catalysis the efficientconversion of different epoxides to their corresponding thiiranes in the presence of ammonium thiocyanate in exellent yields. Stereospecific conversion of R(+) styrene oxide to S(−) styrene sulfide was achieved in high optical purity.