233595-58-9Relevant academic research and scientific papers
Reaction of α-(N-carbamoyl)alkylcuprates with propargyl substrates: Synthetic route to α-amino allenes and Δ3-pyrrolines
Dieter, R. Karl,Chen, Ningyi,Yu, Huayun,Nice, Lois E.,Gore, Vinayak K.
, p. 2109 - 2119 (2007/10/03)
(Chemical Equation Presented) Carbamate deprotonation followed by treatment with CuCN·2LiCl affords α-(N-carbamoyl)-alkylcuprates which react with propargyl halides, mesylates, tosylates, phosphates, acetates, and epoxides to give α-(N-carbamoyl) allenes via an anti-SN2′ substitution process. Propargyl halides, sulfonates, and phosphates give good yields of carbamoyl allenes, while the acetates afford low yields. Propargyl substrates undergo regiospecific SN2′ substitution in the absence of severe steric hindrance. The α-(N-carbamoyl) allenes can be cyclized to 2-oxazolidinones or deprotected to afford the free amines which can be cyclized to Δ3-pyrrolines with either AgNO3 or Ru3(CO)12.
Reactivity and Enantioselectivity in the Reactions of Scalemic Stereogenic α-(N-Carbamoyl)alkylcuprates
Dieter, R. Karl,Oba, Gabriel,Chandupatla, Kishan R.,Topping, Chris M.,Lu, Kai,Watson, Rhett T.
, p. 3076 - 3086 (2007/10/03)
Stereogenic 2-(N-carbamoyl)pyrrolidinylcuprates prepared from scalemic (i.e., enantioenriched) N-Boc-2-lithiopyrrolidine and THF soluble CuCN·2LiCl react with vinyl iodides, vinyl triflates, β-iodo-α,β-enoates, propargyl mesylates, and allyl bromide to afford the substitution products with excellent enantioselectivity. Excellent enantiomeric ratios are obtained in the conjugate addition reactions with methyl vinyl ketone while low enantiomeric ratios can be achieved with acrylate esters using HMPA/TMSCl activation. Enantiomeric ratios vary with substrate substitution patterns and the observed enantioselectivities appear to be more a function of cuprate-electrophile reactivities than of the reaction type (e.g., substitution, conjugate addition). Low enantiomeric ratios are obtained with the α-(N-carbamoyl)benzylcuprates. The lithium-copper transmetalation and cuprate vinylation reactions proceed with retention of configuration.
Synthesis of amino allenes via reaction of α-aminoalkylcuprates with propargyl substrates
Dieter, R. Karl,Nice, Lois E.
, p. 4293 - 4296 (2007/10/03)
α-Aminoalkylcuprates prepared from carbamates via sequential deprotonation and treatment with CuCN · 2LiCl react with propargyl bromides, mesylates, tosylates, acetates, and epoxides to afford amino allenes via a S(N)2' substitution process. Propargyl bromides and sulfonates give good yields of amino allenes while the acetates afford low yields. Substrates undergo regiospecific S(N)2' substitution and the use Sc(OTf)3 affords improved yields of amino allenes from propargyl epoxides. The Boc protected α-amino allenes can be cyclized to oxazolidones or deprotected to afford the free amines.
