944338-99-2Relevant academic research and scientific papers
α-Pyridylation of chiral amines via urea coupling, lithiation and rearrangement
Clayden, Jonathan,Hennecke, Ulrich
supporting information; experimental part, p. 3567 - 3570 (2009/05/07)
(Chemical Equation Presented) 2-, 3- and 4-Bromopyridine, along with other brominated electron-deficient arenes, undergo palladium-catalyzed coupling with ureas of structure RNMeCONHMe. Where R is a chiral, α-substituted benzyl group, treatment with LDA leads to a benzylic organolithium which undergoes rearrangement with stereospecific and regiospecific transfer of the pyridyl group, generating a quaternary stereogenic center with high enantioselectivity. Alcoholysis of the urea under neutral conditions reveals the pyridyl amine.
Substituted diarylmethylamines by stereospecific intramolecular electrophilic arylation of lithiated ureas
Clayden, Jonathan,Dufour, Jeremy,Grainger, Damian M.,Helliwell, Madeleine
, p. 7488 - 7489 (2008/02/11)
On lithiation, N-benzyl ureas varying N′-aryl substituents undergo a migration of the aryl ring to the ∞ carbon of the N-benzyl group. With chiral, enantiomerically pure N-∞-methylbenzyl ureas, the rearrangement is stereospecific and creates a new, fully substituted stereogenic center ∞ to N. Removal of the urea function by N-nitrosation and hydrolysis allows the synthesis of chiral tertiary carbinamines in high enantiomeric purity. Copyright
