N-Carbamate α-aminoalkyl-p-tolylsulfones—convenient substrates in the nitro-Mannich synthesis of secondary N-carbamate protected syn-2-amino-1-nitroalkanephosphonates
摘要:
An efficient one-pot synthesis of secondary N-carbamate protected syn-beta-amino-alpha-nitroalkanephosphonates using diethyl nitromethanephosphonate and N-Boc or N-Cbz imines, generated in Situ from stable N-Boc or N-Cbz alpha-aminoalkyl-p-tolylsulfones has been developed under PTC conditions. A model enantioselective version of this reaction is also described. Enantioselectivity up to 67% ee is achieved using a chiral thiourea catalyst derived from a cinchona alkaloid. Completely stereoselective conversion of the title compounds into partially N-carbamate protected syn-1,2-diaminoalkanephosphonates has also been elaborated. (C) 2010 Elsevier Ltd. All rights reserved.
N-Carbamate α-aminoalkyl-p-tolylsulfones—convenient substrates in the nitro-Mannich synthesis of secondary N-carbamate protected syn-2-amino-1-nitroalkanephosphonates
摘要:
An efficient one-pot synthesis of secondary N-carbamate protected syn-beta-amino-alpha-nitroalkanephosphonates using diethyl nitromethanephosphonate and N-Boc or N-Cbz imines, generated in Situ from stable N-Boc or N-Cbz alpha-aminoalkyl-p-tolylsulfones has been developed under PTC conditions. A model enantioselective version of this reaction is also described. Enantioselectivity up to 67% ee is achieved using a chiral thiourea catalyst derived from a cinchona alkaloid. Completely stereoselective conversion of the title compounds into partially N-carbamate protected syn-1,2-diaminoalkanephosphonates has also been elaborated. (C) 2010 Elsevier Ltd. All rights reserved.
N-Carbamate α-aminoalkyl-p-tolylsulfones—convenient substrates in the nitro-Mannich synthesis of secondary N-carbamate protected syn-2-amino-1-nitroalkanephosphonates
An efficient one-pot synthesis of secondary N-carbamate protected syn-beta-amino-alpha-nitroalkanephosphonates using diethyl nitromethanephosphonate and N-Boc or N-Cbz imines, generated in Situ from stable N-Boc or N-Cbz alpha-aminoalkyl-p-tolylsulfones has been developed under PTC conditions. A model enantioselective version of this reaction is also described. Enantioselectivity up to 67% ee is achieved using a chiral thiourea catalyst derived from a cinchona alkaloid. Completely stereoselective conversion of the title compounds into partially N-carbamate protected syn-1,2-diaminoalkanephosphonates has also been elaborated. (C) 2010 Elsevier Ltd. All rights reserved.