3453-63-2Relevant academic research and scientific papers
Modified Julia Olefination on Anhydrides: Extension and Limitations. Application to the Synthesis of Maculalactone B
Dussart, Nicolas,Trinh, Huu Vinh,Gueyrard, David
supporting information, p. 4790 - 4793 (2016/10/14)
The preparation of exo-enol esters from cyclic anhydrides is reported using a modified Julia olefination. The reaction is highly stereoselective. The Smiles rearrangement can be performed in a one-pot process, giving a straightforward access to exo-enol lactones. Furthermore, the reaction was extended to semistabilized sulfones, and this methodology was applied to the synthesis of maculalactone B.
NHC-catalyzed oxidative cyclization reactions of 2-alkynylbenzaldehydes under aerobic conditions: Synthesis of O-Heterocycles
Park, Jong Hyub,Bhilare, Sachin V.,Youn, So Won
supporting information; experimental part, p. 2228 - 2231 (2011/07/09)
Chemical equations presented. An NHC-catalyzed, regio- and stereoselective oxidative cyclization of o-alkynylbenzaldehydes bearing an unactivated alkyne moiety as an internal electrophile has been developed to afford phthalides and isocoumarins. A single organocatalytic system enabled two sequential C-O bond formations to take place in an atom economical manner via highly efficient dual activation. Molecular oxygen in air could be utilized as a source of an oxygen atom for the oxidation of aldehydes to the corresponding benzoic acids under our newly developed reagent system.
One-pot synthesis of phthalides via regioselective intramolecular cyclization from ortho-alkynylbenzaldehydes
Li, Jim,Chin, Elbert,Lui, Alfred S.,Chen, Lijing
scheme or table, p. 5937 - 5939 (2010/11/21)
A one-pot synthesis of phthalides via an intramolecular 5-exo-dig cyclization of ortho-alkynylbenzaldehydes under mild NaClO2 oxidation conditions is described.
Catalytic enantioselective synthesis of chiral phthalides by efficient reductive cyclization of 2-acylarylcarboxylates under aqueous transfer hydrogenation conditions
Zhang, Bo,Xu, Ming-Hua,Lin, Guo-Qiang
supporting information; experimental part, p. 4712 - 4715 (2009/12/08)
A new diamine ligand for asymmetric transfer hydrogenation (ATH) was discovered. The reductive cyclization of 2-acylarylcarboxylates was found to proceed highly stereoselective by the new Ru complex-catalyzed ATH and subsequent In situ lactonization under aqueous conditions. It enables efficient access to a wide variety of 3-substituted phthalides In enantiomerically pure form.
Catalytic activation of the leaving group in the SN2 reaction
Yamamoto, Hirofumi,Pandey, Ghanshyam,Asai, Yumiko,Nakano, Mayo,Kinoshita, Atsushi,Namba, Kosuke,Imagawa, Hiroshi,Nishizawa, Mugio
, p. 4029 - 4032 (2008/02/10)
A novel catalytic activation of the leaving group in the SN2 reaction is achieved as an extension of our mercuric triflate-catalyzed reactions. Derivatives of anilinoethyl 4-pentynoate reacted smoothly with catalytic amounts of Hg(OTf)2 to give indoline derivatives in excellent yield with efficient catalytic turnovers under very mild conditions. The reaction of optically pure secondary alcohol derivatives resulted in inversion of stereochemistry, which is a definitive feature of the S N2 reaction. The procedure is applicable for benzoazepine synthesis.
SYNTHESIS OF ISOCOUMARINS VIA THALLATION-OLEFINATION OF BENZOIC ACIDS
Larock, R. C.,Varaprath, S.,Lau, H. H.,Fellows, C. A.
, p. 5274 - 5284 (2007/10/02)
Benzoic acid and substituted benzoic acids are readily thallated by thallium(III) trifluoroacetate and subsequently reacted with palladium chloride and simple olefins, allylic halides, vinyl halides, or vinyl esters to give isocoumarins.The organic halide reactions are catalytic in palladium. 1,2- and 1,3-dienes also react catalytically to afford 4-alkylidene- and 3-vinyl-3,4-dihydroisocoumarins, respectively.Vinylcyclopropanes also afford 3-vinyl-3,4-dihydroisocoumarins.This highly convenient thallation-olefination approach appears quite general for the synthesis of isocoumarins.
