Activation of sp3 C-H bonds with cobalt(I): catalytic synthesis of enamines.
C-H bond activation has been extensively studied with (Cp*)M(L)n (M = Ir, Rh), but cobalt, the third member of this triad, has not previously been shown to activate sp3 C-H bonds. Further, practical functionalization of the metal alkyl products of oxidative addition has not been fully explored. Toward these ends, we have developed catalytic dehydrogenation of alkyl amines with a Co(I) catalyst. Amine substrates are protected with vinyl silanes, followed by catalytic transfer hydrogenation, to yield a broad range of stable protected enamines and 1,2-diheteroatom-substituted alkenes, including several unprecedented heterocycles. (Cp*)Co(VTMS)2 catalyzes transfer hydrogenation under surprisingly mild conditions with high chemo-, regio-, and diastereoselectivity, while tolerating additional functionality.
Bolig
Andrew D
AD
Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, USA.
Brookhart
Maurice
M
D000588:Amines / Q000138:chemical synthesis* / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D015394:Molecular Structure
D000588:Amines; D003035:Cobalt; D002244:Carbon; D006859:Hydrogen