01567nas a2200229 4500008004100000022001400041245016000055210006900215260010600284300001400390490000700404520060700411653001601018653002301034653001701057653003001074653002901104100002901133700002601162700002101188856012801209 2012 eng d a0040-403900aSupported copper triflate as an efficient catalytic system for the synthesis of highly functionalized 2-naphthol Mannich bases under solvent free condition0 aSupported copper triflate as an efficient catalytic system for t aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcAUG a4376-43800 v533 a

Various heterogeneous catalysts (Lewis acid) have been prepared and screened for the synthesis of Betti bases in an attempt to reduce the environmental hazards associated with the conventional homogeneous Lewis acid system. And we found especially Cu(OTf)(2)center dot SiO2 catalyzes the three-component coupling of aldehyde, 2-naphthol, and alicyclic amine to generate Betti base with high efficiency under neat conditions without additional co-catalyst or additive in air. The reaction is not sensitive to water and occurs smoothly in water as well. (c) 2012 Elsevier Ltd. All rights reserved.

10aBetti bases10asingle-crystal XRD10aSolvent-free10aSupported copper triflate10aThree-component coupling1 aDindulkar, Someshwar, D.1 aPuranik, Vedavati, G.1 aJeong, Yeon, Tae uhttps://library.ncl.res.in/content/supported-copper-triflate-efficient-catalytic-system-synthesis-highly-functionalized-2-002682nas a2200253 4500008004100000022001400041245007200055210006900127260007300196300001200269490000900281520182000290653002302110653001802133653002202151653001802173653000802191653002002199100002902219700002702248700002602275700002102301856010602322 2012 eng d a0022-286000aSynthesis and stereochemistry of highly crowded N-benzylpiperidones0 aSynthesis and stereochemistry of highly crowded Nbenzylpiperidon aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a158-1670 v10073 a

A series of N-benzylated 3,5-diakyl-2,6-diarylpiperidin-4-ones 4-8 were conveniently synthesized in significant yields of 68-88% by N-benzylation of the corresponding 2,6-diaryl-3,5-dimethylpiperidin-4-ones 1-3 using different benzyl bromides. Initially, the new piperidone 2,6-bis(4-ethoxypheny1)-3,5-dimethylpiperidin-4-one 3 was synthesized by the condensation of 1:1:2 M ratio of 3-pentanone, ammonium acetate and para-ethoxybenzaldehyde in ethanolic medium. All the synthesized new compounds 3-8 were characterized by their analytical and spectral (IR, H-1 and C-13 NMR) interpretations. The stereochemistry of the new piperidone 3 was elucidated as chair conformation with an equatorial orientation of all substituents, suggested by its vicinal couplings from H-1 NMR spectrum. To investigate the impact on piperidone stereochemistry as well as NMR chemical shifts, all the N-benzylated products 4-8 were compared with their corresponding precursors, and as a result, it is clearly established that all the synthesized N-benzyl piperidones exist in the chair conformation with an equatorial orientation of all the substituents at C-2, C-3, C-5, C-6 and N. Contrary to the probability all N-benzylated compounds retain the same conformation and configuration as their precursors, however, a remarkable change on the chemical shifts are observed. For the further unambiguous confirmation of stereochemistry, the 1-benzyl-3,5-dimethyl-2,6-diphenylpiperidin-4-one 4 was examined by single-crystal X-ray diffraction. The compound 4, C26H27NO, crystallized in a P-1 space group under triclinic system with unit cell dimensions a, b, c (angstrom) and alpha, beta, gamma (degrees) of 10.156(2), 11.002(2), 11.348(4) and 116.74(4), 100.81(3), 100.17(3), respectively. (C) 2011 Elsevier B.V. All rights reserved.

10aChair conformation10aConfiguration10acrystal structure10aN-benzylation10aNMR10aPiperidin-4-one1 aDindulkar, Someshwar, D.1 aParthiban, Paramasivam1 aPuranik, Vedavati, G.1 aJeong, Yeon, Tae uhttps://library.ncl.res.in/content/synthesis-and-stereochemistry-highly-crowded-n-benzylpiperidones-001740nas a2200229 4500008004100000022001400041245015300055210006900208260000800277300001100285490000700296520087400303653003301177653002101210653002301231653004201254653001301296100002901309700002101338700002101359856013001380 2020 eng d a0040-403900aSynthesis of diverse nitrogen fused polycyclic dihydroisoquinoline (DHIQ) derivatives via GBB-based cyclic iminium induced double-annulation cascade0 aSynthesis of diverse nitrogen fused polycyclic dihydroisoquinoli cJUL a1521010 v613 a

A highly efficient and distinct Bronsted acid-mediated unprecedented cyclic iminium induced double annulation cascade (DAC) protocol for the synthesis of novel dihydroindazolo[30,20:2,3]imidazo[5,1-a]isoquinolinamines has been achieved through the three-component Groebke-Blackburn-Bienayme reaction. The transformation is based on sequential cascade processes involving imine formation followed by an intramolecular nucleophilic substitution to generate a highly reactive cyclic iminium species, which would undergo a rapid [4 + 1] formal cycloaddition steps in one-pot fashion. This strategy provides novel skeletally diverse complex nitrogen fused polycyclic DHIQ derivatives by employing readily available substrates and a simple procedure, which would render this method potentially useful in organic synthesis. (C) 2020 Elsevier Ltd. All rights reserved.

10adiversity-oriented synthesis10aExcellent yields10aGBB-based approach10aNovel polycyclic N-fused architecture10aScalable1 aBalwe, Sandip, Gangadhar1 aVagh, Sandip, S.1 aJeong, Yeon, Tae uhttps://library.ncl.res.in/content/synthesis-diverse-nitrogen-fused-polycyclic-dihydroisoquinoline-dhiq-derivatives-gbb-based