is reported. Naphthols were found to undergo facile unprecedented oxidative dearomatization with regioselective hydroxylation with phenyl selenyl bromide in open air conditions. Quaternary stereocenters were developed along with formation of sterically demanding α- and γ-ketols with high yields. Functional group tolerance like esters is revealed. A thorough study of the stereoelectronic demands of the
Organocatalytic Asymmetric Dearomatization Reaction for the Synthesis of Axial Chiral Allene-Derived Naphthalenones Bearing Quaternary Stereocenters
作者:Alemayehu Gashaw Woldegiorgis、Zhao Han、Xufeng Lin
DOI:10.1021/acs.orglett.1c01849
日期:2021.9.3
γ-alkynyl-α-imino esters with complete atom economy is disclosed via chiral phosphoric acid catalysis. This protocol provides facile and efficient access to asymmetric construction of a broad range of axially chiral allene-derived naphthalenones bearing quaternary stereocenters in good yields with high diastereoselectivities and enantioselectivities.
Phenyl trimethyl ammonium tribromide mediated robust one-pot synthesis of spiro-oxacycles – an economic route – stereoselective synthesis of oxaspirohexacyclodieneones
作者:Debayan Sarkar、Manoj Kumar Ghosh、Nilendri Rout
DOI:10.1039/c6ob01116k
日期:——
This paper entails the first recognition of PhenylTrimethylAmmonium Tribromide (PTAB) as an effective reagent for spiro-cyclizations proceeding via oxidative dearomatization. The experiment exhibits economical, metal and ligand free one-pot accomplishment of these significant transformations. The described protocol presents the first generalised methodology of spiro-oxacycle synthesis which can be
An enantioselective arylative dearomatization reaction of β‐naphthols with quinone monoimides has been developed for the first time using a chiralphosphoricacid as the catalyst, the desired enantioenriched cyclohexadienones were prepared with excellent yields and enantioselectivities by a domino Michael addition and aromatization process (up to 99 % yield, up to 98 % ee). This process is operationally
An enantioselective sulfenylation of β-naphthols has been developed for the first time using a newly synthesized cinchona-derived thiourea as the catalyst and N-(arylthio) succinimide (or phthalimide) as an electrophilic sulfur source. Various enantioenriched naphthalenones with an S-containing all-substituted stereocenter were prepared via a dearomatization strategy under mild reaction conditions