16963-29-4Relevant academic research and scientific papers
Studies on quinones. Part 32.1 Regioselective synthesis of benz[b]phenantridines related to phenantroviridone
Valderrama, Jaime A.,Gonzalez, M. Florencia,Valderrama, Claudio
, p. 6039 - 6050 (1999)
The Diels-Alder reaction of juglone (4) and bromojuglone 18 with 1- cyclohexenecarboxaldehyde dimethylhydrazone (3) is described. Through these cycloaddition reactions 8-hydroxy-1,2,3,4-tetrahydrobenz[b]phenantridin- 7,12-dione (5) was obtained in 55 and
Enantioselective N-Heterocyclic Carbene Catalyzed Cyclopentene Synthesis via the β-Azolium Ylide
Scott, Lydia,Nakano, Yuji,Zhang, Changhe,Lupton, David W.
supporting information, p. 10299 - 10303 (2018/07/31)
Herein we report the cycloisomerization of electron-poor 1,5-dienes via the β-azolium ylide to give enantioenriched cyclopentenes. The reaction is mediated by a chiral N-heterocyclic carbene (NHC) catalyst, exploits readily available substrates, has good generality (17 examples), and displays excellent enantioselectivity (mostly >94:6). Studies demonstrating the viability of a related dynamic kinetic resolution are reported, as are those with alternate tethers and derivatizations.
Synthesis of Chromone-Containing Allylmorpholines through a Morita–Baylis–Hillman-Type Reaction
Chernov, Nikita M.,Shutov, Roman V.,Barygin, Oleg I.,Dron, Mikhail Y.,Starova, Galina L.,Kuz'mich, Nikolay N.,Yakovlev, Igor P.
supporting information, p. 6304 - 6313 (2018/11/10)
The first example of an unusual addition of chromone-substituted acrylic acid to enamines is described. The process shows high versatility concerning both enamines and chromones. The reaction is catalyzed by tertiary amines and is highly likely of Morita–
Regiospecific synthesis of neuroprotective 1,4-benzoxazine derivatives through a tandem oxidation-Diels-Alder reaction
Nguyen, Khac Minh Huy,Schwendimann, Leslie,Gressens, Pierre,Largeron, Martine
, p. 3749 - 3756 (2015/03/30)
The tandem oxidation-inverse electron demand Diels-Alder reaction of o-aminophenol derivatives and enamines has been accomplished at room temperature using a stoichiometric amount of manganese dioxide as the oxidant to furnish highly substituted 1,4-benzoxazine cycloadducts with complete regiochemical control. Because of its efficiency in introducing diverse elements in both cycloaddition partners, this one-pot process should allow the assembly of libraries of biologically relevant 1,4-benzoxazine derivatives. In this respect, the 3,3-diphenyl-substituted-1,4-benzoxazine derivative 3n was found to be a potent neuroprotective agent in an animal model of excitotoxic lesions in newborn mice.
Palladium-catalysed amination of aryl- and heteroaryl halides using tert-butyl tetraisopropylphosphorodiamidite as an easily accessible and air-stable ligand
Roiban, Gheorghe-Doru,Mehler, Gerlinde,Reetz, Manfred T.
, p. 2070 - 2076 (2014/04/17)
The phosphorus compound tert-butyl tetraisopropylphosphorodiamidite, prepared from bis(diisopropylamino)chlorophosphine, is an excellent ligand for palladium-catalysed Buchwald-Hartwig amination of aryl- and heteroaryl chlorides and bromides. Based on its ready accessibility and air-stability, this amination protocol is a practical approach to the synthesis of industrially important aryl- and heteroarylamines. Copyright
(t-Bu)2PN=P(i-BuNCH2CH2)3N: New efficient ligand for palladium-catalyzed C-N couplings of aryl and heteroaryl bromides and chlorides and for vinyl bromides at room temperature
Reddy, Ch. Venkat,Kingston, Jesudoss V.,Verkade, John G.
, p. 3047 - 3062 (2008/09/19)
(Chemical Equation Presented) By employing Pd(OAc)2, Cs 2CO3, or NaOH, and the new ligand (t-Bu) 2PN=P(i-BuNCH2CH2)3N (3a), an electronically diverse array of aryl bromides and chlorides possessing base-sensitive substituents (nitro, ester, and keto) provide coupling products with bulky aryl amines in good to excellent yields. Aryl halides possessing other functional groups including cyano, amino, trifluoromethyl, and phenol, coupled with equal ease, producing highly functionalized amines in good to excellent yields. Moreover, an aryl chloro group can be preserved in the presence of a bromo substituent under our reaction conditions. BOC-protected amines also participated efficiently. Heterocyclic bromides and chlorides underwent clean couplings with amines in excellent yields. An important strength of our protocol is the use of lower palladium loadings than those reported earlier, without compromising yields. The air-stable palladium complex (η3-cinnamyl)PdCl·(3a) (5) was also employed successfully in C-N coupling reactions while the crotyl analogue was less efficacious. The 3a/Pd(OAc)2 catalyst system promotes, for the first time, efficient coupling of vinyl bromides with a variety of amines to produce imines and enamines at room temperature.
Cyclobutanones through SNi′ ring closure, a mechanistic study
Lovchik, Martin A.,Goeke, Andreas,Frater, Georg
, p. 2427 - 2433 (2007/10/03)
Mechanistic studies on the intramolecular nucleophilic substitution with allylic rearrangement (SNi′ reaction) and a new stereoselective access to substituted cyclobutanones are reported. 4,4-Dialkyl-5-oxohex-2E-en- 1-yl ethanesulfonates 4 were
A highly effective catalyst system for the Pd-catalyzed amination of vinyl bromides and chlorides
Reddy, Chinta Reddy Venkat,Urgaonkar, Sameer,Verkade, John G.
, p. 4427 - 4430 (2007/10/03)
(Chemical Equation Presented) A highly efficient synthesis of enamines and imines by Pd-catalyzed amination of vinyl bromides or chlorides with amines is described using the Pd2(dba)3/P(i-BuNCH2CH 2)3N catalyst system.
Simultaneously Electrogenerated Cycloaddition Partners for Regiospecific Inverse-Electron-Demand Diels-Alder Reactions: A Route for Polyfunctionalized 1,4-Benzoxazine Derivatives
Blattes, Estelle,Fleury, Maurice-Bernard,Largeron, Martine
, p. 882 - 890 (2007/10/03)
A multistep one-pot electrochemical synthesis of a variety of complex 2-alkylamino-1,4-benzoxazine derivatives is described. The reactions are regiospecific and diastereospecific in the case of heterocyclic annulation. This cascade sequence, wherein both cycloaddition partners are generated in situ, at room temperature, under metal-free conditions, allows the inverse-electron-demand Diels-Alder reaction of an o-iminoquinone diene and a secondary alkylenamine dienophile, two chemically nonaccessible unstable entities. To increase the molecular diversity, a variant in which the enamine is separately prepared completes the aforementioned procedure. The extension of this reaction should be useful to generate libraries of heterocycles.
Regioselective Incorporation of CO into Enamines by Rhodium-Catalyzed Reaction with a Hydrosilane and CO
Ikeda, Shin-ichi,Chatani, Naoto,Kajikawa, Yasuteru,Ohe, Kouichi,Murai, Shinji
, p. 2 - 4 (2007/10/02)
In the presence of 2, the reaction of enamines with a hydrosilane and carbon monoxide (140 deg C, 50 atm of CO) resulted in regioselective incorporation of CO into the α-carbon atom to give α-(siloxymethylene) amines, which can be easily conver
