1449655-53-1Relevant academic research and scientific papers
Rhodium(I)-complexes catalyzed 1,4-conjugate addition of arylzinc chlorides to N-boc-4-pyridone
Guo, Fenghai,McGilvary, Matthew A.,Jeffries, Malcolm C.,Graves, Briana N.,Graham, Shekinah A.,Wu, Yuelin
, (2017)
Rhodium(I)-complexes catalyzed the 1,4-conjugate addition of arylzinc chlorides to N-Boc-4-pyridone in the presence of chlorotrimethylsilane (TMSCl). A combination of [RhCl(C2H4)2]2 and BINAP was determined to be the most effective catalyst to promote the 1,4-conjugate addition reactions of arylzinc chlorides to N-Boc-4-pyridone. A broad scope of arylzinc reagents with both electron-withdrawing and electron-donating substituents on the aromatic ring successfully underwent 1,4-conjugate addition to N-Boc-4-pyridone to afford versatile 1,4-adducts 2-substituted- 2,3-dihydropyridones in good to excellent yields (up to 91%) and excellent ee (up to 96%) when (S)-BINAP was used as chiral ligand.
Conjugate addition reactions of N -carbamoyl-4-pyridones and 2,3-dihydropyridones with grignard reagents in the absence of Cu(I) Salts
Guo, Fenghai,Dhakal, Ramesh C.,Dieter, R. Karl
, p. 8451 - 8464 (2013/09/24)
N-Boc- and N-ethoxycarbonyl-4-pyridones and the resulting 2,3-dihydropyridones undergo 1,4-addition reactions with Grignard reagents in the presence of chlorotrimethylsilane (TMSCl) or BF3·Et 2O in excellent yields. Copper catalysis is not required, and mechanistic considerations suggest that the reaction is proceeding by a conjugate addition pathway rather than by a pathway involving 1,2-addition to an intermediate pyridinium ion. TMSCl-mediated conjugate addition of Grignard reagents to 2-substituted-2,3-dihydropyridones gives the trans-2,6-disubstitued piperidinones stereoselectively, while cuprate reagents give either the trans or cis diastereomers or mixtures.
