19847-64-4Relevant academic research and scientific papers
Taming a Vinyl Cation with a Simple Al(OTf)3 Catalyst To Promote C?C Bond Cleavage
Niggemann, Meike,Fu, Liang,Damsen, Helena
, p. 12184 - 12189 (2017)
A detailed mechanistic investigation identified the stepwise nature of the 1,3-aryl shift, which enables our recently disclosed Al3+-catalyzed insertion of unactivated alkynes into the sp2–sp3 C?C bond of benzyl alcohols. The selectivity for the rearranged product was found to be induced by the continued coordination of the aluminum catalyst to the rearranging species, which is encouraged by a reversible background reaction. This participation of the catalyst beyond the ionization step is unique in the realm of carbocation driven reactions and opens up the possibility of a catalyst-induced chiral induction in the future. Furthermore, the study represents a rare example of detailed mechanistic analysis of a reaction with a product selectivity that changes with increasing conversion.
Alkynes as allylmetal equivalents in redox-triggered C-C couplings to primary alcohols: (Z)-homoallylic alcohols via ruthenium-catalyzed propargyl C-H oxidative addition
Park, Boyoung Y.,Nguyen, Khoa D.,Chaulagain, Mani Raj,Komanduri, Venukrishnan,Krische, Michael J.
, p. 11902 - 11905 (2014/10/15)
The cationic ruthenium catalyst generated upon the acid-base reaction of H2Ru(CO)(PPh3)3 and 2,4,6-(2-Pr) 3PhSO3H promotes the redox-triggered C-C coupling of 2-alkynes and primary alcohols to form (Z)-homoallylic alcohols with good to complete control of olefin geometry. Deuterium labeling studies, which reveal roughly equal isotopic compositions at the allylic and distal vinylic positions, along with other data, corroborate a catalytic mechanism involving ruthenium(0)-mediated allene-aldehyde oxidative coupling to form a transient oxaruthenacycle, an event that ultimately defines (Z)-olefin stereochemistry.
Azo and Azoxy Compounds: XII. Use of Nitrogen Oxide in Organic Synthesis
Yandovskii,Tselinskii
, p. 147 - 152 (2007/10/03)
Thermal elimination of the alkoxydiazene oxide group from the derivatives of acyl- and benzoylalkanes (cycloalkanes) afforded the corresponding vinyl ketones. Addition of nitrogen oxide and alkoxides to vinyl ketones followed by removal of the acyl group yielded 1,4-dialkoxy-1,2-diazabut-1-ene 2-oxides.
Enantioselective Synthesis of α-Hydroxyketones using the DiTOX Asymmetric Building Block
Page, Philip C. Bulman,Purdle, Mark,Lathbury, David
, p. 8929 - 8932 (2007/10/03)
The 2-(R)- and 2-(S)-hydroxy-1-phenylbutan-1-ones have been prepared in high enantiomeric excesses and in five steps from propanal using a dithiane oxide unit as an asymmetric building block and a modified Sharpless enantioselective sulphur oxidation as the source of chirality.
Cobalt(II) Chloride Catalyzed Acylation of Alcohols with Acetic Anhydride: Scope and Mechanism
Iqbal, Javed,Srivastava, Rajiv Ranjan
, p. 2001 - 2007 (2007/10/02)
Cobalt(II) chloride catalyzes the acetylation of a variety of alcohols with acetic anhydride in excellent yield.Primary hydroxyl groups can be selectively acylated in the presence of secondary and tertiary ones while the secondary hydroxyl groups can be preferentially acetylated in the presence of tertiary ones.Tertiary alcohols have been found to give ketones, acetoacetates, olefins, and diketene in addition to the acetate.The β-hydroxy esters and ketones can be acylated under these conditions without any elimination, and this reaction has been compared with 4-(dimethylamino)pyridine (DMAP)-mediated acylations where elimination of the resulting β-acetoxy carbonyl compound is observed.A detailed investigation of the acylation of tertiary alcohols has revealed that these reactions proceed via a tertiary alkoxy radical and ketene.A mechanism for these acylations is proposed by invoking an electron-transfer process.
