Reaction of alpha-(N-carbamoyl)alkylcuprates with propargyl substrates: synthetic route to alpha-amino allenes and delta3-pyrrolines.
[reaction: see text] Carbamate deprotonation followed by treatment with CuCN.2LiCl affords alpha-(N-carbamoyl)alkylcuprates which react with propargyl halides, mesylates, tosylates, phosphates, acetates, and epoxides to give alpha-(N-carbamoyl) allenes via an anti-S(N)2' substitution process. Propargyl halides, sulfonates, and phosphates give good yields of carbamoyl allenes, while the acetates afford low yields. Propargyl substrates undergo regiospecific S(N)2' substitution in the absence of severe steric hindrance. The alpha-(N-carbamoyl) allenes can be cyclized to 2-oxazolidinones or deprotected to afford the free amines which can be cyclized to Delta(3)-pyrrolines with either AgNO(3) or Ru(3)(CO)(12).
Dieter
R Karl
RK
Department of Chemistry, Howard L. Hunter Laboratory, Clemson University, Clemson, South Carolina 29634-0973, USA.
Chen
Ningyi
N
Yu
Huayun
H
Nice
Lois E
LE
Gore
Vinayak K
VK
D000466:Alkadienes / Q000138:chemical synthesis*; D000480:Alkynes / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D020005:Propanols / Q000737:chemistry*; D011758:Pyrroles / Q000138:chemical synthesis*
D000466:Alkadienes; D000480:Alkynes; D009942:Organometallic Compounds; D020005:Propanols; D011758:Pyrroles; D003300:Copper; C028255:propargyl alcohol