Tungsten Hexachloride (WCl<sub>6</sub>) in the Presence of Dimethylsulfoxide Promoted Facile and Efficient One-Pot Ring Expansion-Chlorination Reactions of 1,3-Dithiolanes and 1,3-Dithianes
作者:Habib Firouzabadi、Nasser Iranpoor、Babak Karimi
DOI:10.1055/s-1999-2628
日期:1999.4
Tungsten hexachloride (WCl6) in the presence of DMSO could be efficiently used for the conversion of 1,3-dithiolanes and 1,3-dithianes to their corresponding chlorinated derivatives of dihydro-1,4-dithiin and dihydro-1,4-dithiepine in high yield, respectively.
Reactions of Silica Chloride (SiO<sub>2</sub>Cl)/DMSO, a Heterogeneous System for the Facile Regeneration of Carbonyl Compounds from Thioacetals and Ring-Expansion Annelation of Cyclic Thioacetals
Thioketals without enolizable hydrogens adjacent to a sulfur atom are converted easily to the corresponding ketones in high yields under similar reaction conditions. However, thioketals with enolizable methyl and methylene groups undergo ring-expansion reactions to afford 1,4-dithiepins and 1,4-dithiins in dry CH(2)Cl(2) at room temperature in good yields.
Rapid Method for the Ring Expansion of 1,3-Dithiolanes and 1,3-Dithianes with <i>tert</i>-Butyl Hypochlorite
作者:K. Akamanchi、Nitin Arote、Vikas Telvekar
DOI:10.1055/s-2005-921906
日期:——
A new method for the ring expansion of 1,3-dithiolanes and 1,3-dithianes to dihydro-1,4-dithiins and dihydro-1,4-dithiepines, respectively, using tert-butylhypochlorite at room temperature is described. The salient features of the protocol include mild reaction conditions, very short reaction time, and high yield.
New Applications of 2,4,6-Trichloro-1,3,5-triazine (TT) in Synthesis: Highly Efficient and Chemoselective Deprotection and Ring-Enlargement of Dithioacetals and Oxathioacetals
作者:Babak Karimi、Hassan Hazarkhani
DOI:10.1055/s-2003-42459
日期:——
Efficient deprotection of a wide variety of 1,3-dithioacetals and 1,3-oxathiolanes to the corresponding carbonyl compounds at room temperature using a combination of 2,4,6-trichloro-1,3,5-triazine (TT) and dimethyl sulfoxide (DMSO) was investigated. In this way, 1,3-oxathioacetals and 1,3-dithioacetals of enolizable ketones were converted to the corresponding 1,4-oxathiepine and 1,4-dithiepine derivatives, respectively.
A one-pot synthesis of 1,4-dithiins and 1,4-benzodithiins from ketones using the recyclable reagent 1,1′-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT)
作者:Siva Murru、Veerababurao Kavala、C.B. Singh、Bhisma K. Patel
DOI:10.1016/j.tetlet.2006.12.003
日期:2007.2
the corresponding ketones in one-pot using the recyclable reagent, 1,1′-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) is described. This method is mild, simple, environmentally benign and is applied successfully for the ringexpansion of 1,3-dithiolane to 1,4-dithiins and the ringexpansion associated with aromatisation of cyclicketones with or without double bonds in the ring. The main feature