ortho-Acidic aromatic thiols as efficient catalysts of intramolecular Morita–Baylis–Hillman and Rauhut–Currier reactions
作者:Philipp S. Selig、Scott J. Miller
DOI:10.1016/j.tetlet.2010.11.077
日期:2011.4
ortho-Mercaptobenzoic acid and ortho-mercaptophenols were discovered as efficient thiol catalysts of both the intramolecular Morita–Baylis–Hillman (MBH) and Rauhut–Currier (RC) reaction. High reaction rates were achieved under mildly basic, aqueous conditions. The unprecedented catalytic activity of these protic nucleophiles could originate from a Brønsted acid induced destabilization of intermediate
Triflic Acid-Catalyzed Enynes Cyclization: A New Strategy beyond Electrophilic π-Activation
作者:Zhunzhun Yu、Lu Liu、Junliang Zhang
DOI:10.1002/chem.201601599
日期:2016.6.13
The cyclization of enynes, catalyzed by a transition metal, represents a powerful tool to construct an array of cyclic compounds through electrophilic π‐activation. In this paper, we disclose a new and efficient strategy for enynes cyclizationcatalyzed by triflic acid. The salient features of this transformation includes a broad substrate scope, metal free synthesis, open flask and mild conditions
intramolecular Rauhut–Currier reaction of linear bis(enones) has been achieved via double activation catalysis of thiols and phase transfer substances, furnishing both enantioenriched cyclohexene and cyclopentene derivatives (up to 95% ee). Furthermore, the desymmetric version of prochiral substrates was developed under similar catalysis, producing the frameworks bearing an additional tertiary or even quaternary
Tandem Michael/Michael reactions mediated by phosphines or aryl thiolates
作者:Paul M Brown、Nina Käppel、Patrick J Murphy
DOI:10.1016/s0040-4039(02)02142-1
日期:2002.11
Tri-n-Butyl phosphine was found to effect tandem Michael/Michael cyclisations leading to the formation of cyclopentenes and cyclohexenes in good yields, whilst p-TolSH in conjunction with a catalytic amount of p-TolSNa effected cyclisation to the corresponding cyclopentanes and cyclohexanes. (C) 2002 Published by Elsevier Science Ltd.
Organocatalytic Michael Cycloisomerization of Bis(enones): The Intramolecular Rauhut−Currier Reaction
作者:Long-Cheng Wang、Ana Liza Luis、Kyriacos Agapiou、Hye-Young Jang、Michael J. Krische
DOI:10.1021/ja0121686
日期:2002.3.1
The utilization of enones as latent enolates enables regioselective enolate formation from chemically robust presursors. In this communication, we report a catalytic Michael cycloisomerization of bis(enones) under Morita-Baylis-Hillman conditions. Upon exposure to 10 mol % tributylphosphine, bis(enone) substrates afford both five- and six-membered ring products. Notably, unsymmetrical bis(enones) possessing sufficient steric or electronic bias yield single isomeric products.