Successively Recycle Waste as Catalyst: A One-Pot Wittig/1,4-Reduction/Paal–Knorr Sequence for Modular Synthesis of Substituted Furans
摘要:
A one-pot tandem Wittig/conjugate reduction/PaalKnorr reaction is reported for the synthesis of di- or trisubstituted furans. This novel sequence first demonstrates the possibility of successively recycling waste from upstream steps to catalyze downstream reactions.
X-ray Absorption and Electron Paramagnetic Resonance Guided Discovery of the Cu-Catalyzed Synthesis of Multiaryl-Substituted Furans from Aryl Styrene and Ketones Using DMSO as the Oxidant
serving not only as a solvent but also as an oxidant to promote the oxidation of Cu(I) to Cu(II) has been demonstrated. X-ray absorption and electron paramagnetic resonance evidence revealed a single-electron redox process where DMSO could oxidize Cu(I) to Cu(II). The novel discovery guided the rational design of copper-catalyzed oxidative cyclization of aryl ketones with styrenes to furans, providing a new
Brønsted Acid-Catalyzed Cycloisomerization of But-2-yne-1,4-diols with or without 1,3-Dicarbonyl Compounds to Tri- and Tetrasubstituted Furans
作者:Srinivasa Reddy Mothe、Sherman Jun Liang Lauw、Prasath Kothandaraman、Philip Wai Hong Chan
DOI:10.1021/jo301093f
日期:2012.8.17
efficiently from cycloisomerization of but-2-yne-1,4-diols with or without 1,3-dicarbonyl compounds is described. By taking advantage of the orthogonal modes of reactivity of the alcoholic substrate through slight modification of the reaction conditions, a divergence in product selectivity was observed. At roomtemperature, p-TsOH·H2O-mediated tandem alkylation/cycloisomerization of the propargylic
Radical Based Strategy toward the Synthesis of 2,3-Dihydrofurans from Aryl Ketones and Aromatic Olefins
作者:Togati Naveen、Rajesh Kancherla、Debabrata Maiti
DOI:10.1021/ol502688r
日期:2014.10.17
with a wide range of aromatic olefins has been developed. This strategy allowed convenient access to 2,3-dihydrofuran derivatives. The versatility of the protocol is shown by synthesizing α-methyl dihydrofurans, which serve as an intermediate for the synthesis of vitamin B1. In addition, the applicability of the protocol in conjugated systems is demonstrated. A radical pathway was presumed and supported
A base-catalysed [3 + 2] cycloaddition reaction of propargylamines and aldehydes for the regiospecific synthesis of substituted furans under metal-free conditions is developed. Propargylamines are used as allenyl anion equivalents and applied in [3 + 2] cycloaddition reactions with aldehydes. Various substituted furans are provided up to 91% yield for 28 examples.
A one-pot tandem Wittig/conjugate reduction/PaalKnorr reaction is reported for the synthesis of di- or trisubstituted furans. This novel sequence first demonstrates the possibility of successively recycling waste from upstream steps to catalyze downstream reactions.