505-23-7Relevant articles and documents
Kinetics of the [2+ + 4]-cycloaddition reactions of 1,3-dithian-2-ylium ions with 1,3-dienes
Mayr, Herbert,Henninger, Joachim
, p. 1919 - 1922 (1998)
The kinetics of the [2+ + 4] cycloadditions of 1,3-dithian-2-yhum ions (1) with 1,3-dienes was investigated photometrically in dichloromethane. The second-order rate constants determined for the reactions of 1 with 2,3-dimethyl-1,3-butadiene (2a) and isoprene (2b) were identical to those calculated for the first step of a stepwise cycloaddition pathway by the correlation Ig k = s (E + N). Though a concerted cycloaddition pathway is not excluded by this finding, it is obvious that the transition states of these reactions are not noticeably stabilized by the simultaneous formation of two new σ bonds.
Electrophilic Chlorine from Chlorosulfonium Salts: A Highly Chemoselective Reduction of Sulfoxides
Acosta-Guzmán, Paola,Mahecha-Mahecha, Camilo,Gamba-Sánchez, Diego
supporting information, p. 10348 - 10354 (2020/07/13)
Herein, we describe a selective late-stage deoxygenation of sulfoxides based on a novel application of chlorosulfonium salts and demonstrate a new process using these species generated in situ from sulfoxides as the source of electrophilic chlorine. The use of highly nucleophilic 1,3,5-trimethoxybenzene (TMB) as the reducing agent is described for the first time and applied in the deoxygenation of simple and functionalized sulfoxides. The method is easy to handle, economic, suitable for gram-scale operations, and readily applied for poly-functionalized molecules, as demonstrated with more than 45 examples, including commercial medicines and analogues. We also report the results of competition experiments that define the more reactive sulfoxide and we present a mechanistic proposal based on substrate and product observations.
Reduction of CO2 into Methylene Coupled with the Formation of C-S Bonds under NaBH4/I2 System
Guo, Zhiqiang,Zhang, Bo,Wei, Xuehong,Xi, Chanjuan
supporting information, p. 6678 - 6681 (2018/10/24)
A selective four-electron reduction of CO2 with thiophenol using NaBH4 as a reductant is described to access dithioacetals. This reaction provides a novel synthetic method for the highly selective conversion of CO2 into methylene, and a new access to molecular structures via formation of C-S bonds using CO2 as the C1 source.
Synthesis of 8-methylnonane-1,6,7-trien-4-one and related allenes as potentially useful synthetic precursors
Mdachi
experimental part, p. 103 - 113 (2012/04/23)
The allenic ketone 8-methylnonane-1,6,7-trien-4-one and related allenes have been synthesized from simple commercially available materials. Since allenes analogous to 8-methylnonane-1,6,7-trien-4-one have previously been transformed to substituted bicyclo[3.3.0]octanones via corresponding bicyclo[3.2.0]heptanones, it is anticipated that the present allenic ketone may also undergo similar transformations. Substituted bicyclo[3.3.0]octanones are known synthetic precursors of tricyclic sesquiterpenes. Thus, 8-methylnonane-1,6,7- trien-4-one presents itself as a possible precursor for the synthesis of tricyclopentanoid ring system present in sesquiterpenes such as hirsutene and Δ9(12)-capnellene.
