NHC-Catalyzed Enantioselective Dearomatizing Hydroacylation of Benzofurans and Benzothiophenes for the Synthesis of Spirocycles
作者:Daniel Janssen-Müller、Mirco Fleige、Danny Schlüns、Marco Wollenburg、Constantin G. Daniliuc、Johannes Neugebauer、Frank Glorius
DOI:10.1021/acscatal.6b01852
日期:2016.9.2
Benzofurans and benzothiophenes have been efficiently employed as substrates in an enantioselective intramolecular hydroacylation. Breaking aromaticity in a 5-exo-trig cyclization of easily accessible heteroarenes by NHC-catalyzedhydroacylation gives access to a simple class of mainly unexplored spirocycles with up to 99% enantiomeric excess (ee). The formed product class bears interesting three-dimensional
TOMINAGA, YOSHINORI;LEE, M. L.;CASTLE, R. N., J. HETEROCYCL. CHEM., 1981, 18, N 5, 967-972
作者:TOMINAGA, YOSHINORI、LEE, M. L.、CASTLE, R. N.
DOI:——
日期:——
Ultrasound assisted Bradsher reaction in aqueous and non-aqueous media: First use of ultrasounds in electrophilic aromatic cyclisation leading to polyacenes
作者:Emilia Kowalska、Piotr Bałczewski
DOI:10.1016/j.ultsonch.2016.07.010
日期:2017.1
ortho-formyl diarylmethanes. This reaction is also the first example of electrophilic, aromatic cyclisation assisted by ultrasounds which leads to pure polycyclic, fused aromatic hydrocarbons containing 3 and 4 fused rings in excellent yields. The reaction proceeds not only in aqueous but also in non-aqueous media at milder conditions (room temperature) and in much shorter reaction times than in conventional