- Conjugate Addition Routes to 2-Alkyl-2,3-dihydroquinolin-4(1H)-ones and 2-Alkyl-4-hydroxy-1,2-dihydroquinoline-3-carboxylates
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Under CuBr·SMe2/PPh3 catalysis (5/10 mol-%) RMgCl (R = Me, Et, nPr, CH=CH2, nBu, iBu, nC5H11, cC6H11, Bn, CH2Bn, nC11H23) readily (–78 °C) undergo 1,4-addition to Cbz or Boc protected quinolin-4(1H)-ones to provide 2-alkyl-2,3-dihydroquinolin-4(1H)-ones (14 examples, 54–99 % yield). Asymmetric versions require AlEt3 to Boc-protected ethyl 6-substituted 4(1H)-quinolone-3-carboxylates (6-R group = all halogens, n/i/t-alkyls, CF3) and provide 61–91 % yield, 30–86 % ee; any halogen, Me, or CF3 provide the highest stereoselectivities (76–86 % ee). Additions of AlMe3 or Al(nC8H17)3 provide ≈ 45 and ≈ 75 % ee on addition to the parent (6-R = H). Ligand (S)-(BINOL)P–N(CHPh2)(cC6H11) provides the highest ee values engendering addition to the Si face of the 4(1H)-quinolone-3-carboxylate. Allylation and deprotection of a representative 1,4-addition product example confirm the facial selectivity (X-ray crystallography).
- Kingsbury, Alex,Brough, Steve,McCarthy, Antonio Pedrina,Lewis, William,Woodward, Simon
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p. 1011 - 1017
(2019/12/27)
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- Highly Enantioselective Catalytic Addition of Grignard Reagents to N-Heterocyclic Acceptors
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General methods to prepare chiral N-heterocyclic molecular scaffolds are greatly sought after because of their significance in medicinal chemistry. Described here is the first general catalytic methodology to access a wide variety of chiral 2- and 4-substituted tetrahydro-quinolones, dihydro-4-pyridones, and piperidones with excellent yields and enantioselectivities, utilizing a single catalyst system.
- Guo, Yafei,Harutyunyan, Syuzanna R.
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p. 12950 - 12954
(2019/08/07)
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- Tetrahydroquinoline derivatives as CRTH2 antagonists
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The invention relates to compounds of formula (I) wherein R1, R2, R3, R4, R5, R6, R7 and R8 are as defined in the description, their use as medicament, pharmaceutical compositions containing them and processes for their preparation.
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- Quinoline derivatives as CRTH2 antagonists
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The invention relates to compounds of formula (I) wherein R1, R2, R3, R4, R5, R6, R7 and R8 are as defined in the description, their use as medicament, pharmaceutical compositions containing them and processes for their preparation.
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