849203-60-7Relevant articles and documents
Oxidative Ring Expansion of Cyclobutanols: Access to Functionalized 1,2-Dioxanes
Lapez, Mara-A Marta-N,Jamey, Nicolas,Pinet, Alexis,Figadeìre, Bruno,Ferri, Laurent
, p. 1626 - 1631 (2021/03/08)
Cyclobutanols undergo an oxidative ring expansion with Co(acac)2 and triplet oxygen to give 1,2-dioxanols. The formation of an alkoxy radical drives the regioselective cleavage of the ring on the more substituted side before insertion of molecular oxygen. The reaction is particularly effective on secondary cyclobutanols but works also on certain tertiary alcohols. Further substitution with neutral nucleophiles under catalytic Lewis acid conditions led to original 1,2-dioxanes with a preferred 3,6-cis-configuration.
Use of cyclopropyl diphenylsulfonium trifluoromethanesulfonate as sulfur ylide reagent and method for preparation of four-membered cyclic ketone
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Paragraph 0019; 0020; 0021; 0022, (2017/08/28)
The invention provides a use of cyclopropyl diphenylsulfonium trifluoromethanesulfonate as a sulfur ylide reagent and a method for preparation of four-membered cyclic ketone. The cyclopropyl diphenylsulfonium trifluoromethanesulfonate solves the problem that cyclopropyl diphenylsulfonium tetrafluoroborate as the traditional sulfur ylide reagent used in the synthesis of a four-membered cyclic ketone compound from aldehydes or ketones has large synthesis difficulty, complex operation and an expensive price. Under the same reaction conditions, the reactivity of cyclopropyl diphenylsulfonium trifluoromethanesulfonate is comparable to that of cyclopropyl diphenylsulfonium tetrafluoroborate and thus the cyclopropyl diphenylsulfonium trifluoromethanesulfonate can replace cyclopropyl diphenylsulfonium tetrafluoroborate and be used as a novel sulfur ylide reagent.
Synthesis of four novel natural product inspired scaffolds for drug discovery
Jenkins, Ian D.,Lacrampe, Fabienne,Ripper, Justin,Alcaraz, Lilian,Van Le, Phuc,Nikolakopoulos, George,De Leone, Priscila Almeida,White, Rodney H.,Quinn, Ronald J.
supporting information; experimental part, p. 1304 - 1313 (2009/07/04)
Inspired by the novel spiro structures of a number of bioactive natural products such as the histrionicotoxins, a series of novel spiro scaffolds have been designed and robust syntheses developed. The scaffolds are ready-to-use building blocks and can be easily prepared on a 5-20 g scale. They contain two amino groups (one Boc-protected) and have been designed for ease of conversion to a lead generation library, using either amide formation or reductive amination procedures. The synthesis of the 1,9-diazaspiro[5.5]undecane and 3,7-diazaspiro[5.6]dodecane ring systems was achieved using RCM as the key step. A simple workup procedure is reported for the removal of highly colored ruthenium residues. The synthesis of the 1,8-diazaspiro[4.5]decane scaffold has been achieved using a bromine-mediated 5-endo cyclization of the corresponding 4-aminobutene intermediate under acidic conditions. This is the first example of this type of cyclization to be reported. A novel mechanism involving a bromine transfer reaction from an initially formed bromonium ion to a neighboring nitrogen atom is suggested as the reason for the failure of this type of reaction under "normal" bromination conditions. An unusual rearrangement of a 1-acyl-1,9-diazaspiro[5.5]undecane to the corresponding 9-acyl-1,9-diazaspiro[5.5]undecane is reported.
