491-30-5Relevant articles and documents
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Brown,White
, p. 1589,1591 (1957)
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Ono,Hata
, p. 3658,3660 (1973)
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Efficient visible light mediated synthesis of quinolin-2(1H)-ones from quinolineN-oxides
Bhuyan, Samuzal,Chhetri, Karan,Hossain, Jagir,Jana, Saibal,Mandal, Susanta,Roy, Biswajit Gopal
supporting information, p. 5049 - 5055 (2021/07/29)
Quinolin-2(1H)-ones are one of the important classes of compounds due to their prevalence in natural products and in pharmacologically useful compounds. Here we present an unconventional and hitherto unknown photocatalytic approach to their synthesis from easily available quinoline-N-oxides. This reagent free highly atom economical photocatalytic method, with low catalyst loading, high yield and no undesirable by-product, provides an efficient greener alternative to all conventional synthesis reported to date. The robustness of the methodology has been successfully demonstrated with easy scaling up to the gram scale.
Synthesis of Overloaded Cyclopentadienyl Rhodium(III) Complexes via Cyclotetramerization of tert-Butylacetylene
Kolos, Andrey V.,Nelyubina, Yulia V.,Perekalin, Dmitry S.,Sundararaju, Basker
supporting information, p. 3712 - 3719 (2021/09/18)
Herein we describe the synthesis and reactivity of rhodium catalysts with the very bulky cyclopentadienyl ligand C8H3tBu4 (designated as tBu4Cp). The reaction of [Rh(cod)Cl]2 with tert-butylacetylene in the presence of Et3N gives the complex (tBu4Cp)Rh(cod) (60-65% yield), in which the cyclopentadienyl ligand tBu4Cp is assembled from four alkyne molecules. The oxidation of (tBu4Cp)Rh(cod) with chlorine or bromine gives the corresponding halide complexes (tBu4Cp)RhX2 (X = Cl (85%), Br (95%)), which have unusual 16-electron monomeric structures due to the steric shielding provided by tBu groups. A similar reaction with iodine gives the ionic dinuclear complex [(tBu4Cp)RhI3Rh(tBu4Cp)]I (99%) with halide bridges. The bromide complex (tBu4Cp)RhBr2 reacts with phosphorus ligands such as P(OMe)3, P(OPh)3, PMe2Ph, and PMePh2 to give the 18-electron adducts (tBu4Cp)RhBr2(PR3), but no reaction occurs with larger phosphines such as PPh3. The racemic chloride (tBu4Cp)RhCl2 can be separated into enantiomers by preparative TLC of its diastereomeric adducts with (R)-phenylglycinol. The complex (tBu4Cp)RhBr2 catalyzes C-H activation and annulation of O-pivaloyl-hydroxamate as well as insertion of phenyldiazoacetate into E-H bonds, although the reaction rates and the substrate scope are limited by the bulky tBu4Cp ligand.
Ruthenium(II)-Catalyzed C?H Activation/Annulation of Aromatic Hydroxamic Acid Esters with Enamides Leading to Aminal Motifs
Dana, Suman,Sureshbabu, Popuri,Giri, Chandan Kumar,Baidya, Mahiuddin
supporting information, p. 1385 - 1389 (2021/02/26)
Hydroxamic acid ester directed C(sp2)?H activation/annulation strategy has been reported employing electron-rich enamides under Ru(II)-catalysis to access aminal frameworks. Both N-vinyl acetamide and N-vinyl formamide delivered aminals bearing
