(R)-5-Hydroxy-2-methyl-2-nitro-pentanoic acid tert-butyl ester | 185054-65-3

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: (R)-5-Hydroxy-2-methyl-2-nitro-pentanoic acid tert-butyl ester
• 英文别名: tert-butyl (2R)-5-hydroxy-2-methyl-2-nitropentanoate
• CAS: 185054-65-3
• 化学式: C₁₀H₁₉NO₅
• 分子量: 233.265
• InChiKey: FMQYGNOIDDUMNQ-SNVBAGLBSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.4
• 重原子数：
  16
• 可旋转键数：
  6
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.9
• 拓扑面积：
  92.4
• 氢给体数：
  1
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  (R)-5-Hydroxy-2-methyl-2-nitro-pentanoic acid tert-butyl ester 在 palladium on activated charcoal 重铬酸吡啶 、 Amberlite IR-120B H⁺ form 、 甲酸铵 、 三氟乙酸 作用下， 反应 15.0h， 生成 (R)-α-methyl-glutamic acid
  参考文献：
  名称：

  Enantioselective Allylation of Nitro Group-Stabilized Carbanions Catalyzed by Chiral Crown Ether Phosphine−Palladium Complexes

  摘要：

  Enantioselective allylations of alpha-nitro ketones (3) and alpha-nitro esters (15) with allyl acetate were carried out in the presence of 2 equiv of alkali metal fluorides (KF, RbF, CsF) and 1 mol % of palladium catalysts prepared in situ from Pd-2(dba)(3) . CHCl3 and chiral phosphine ligands. Moderate enantioselectivities were observed in the reaction of nitro ketones 3, giving products 4 (4a, 49% ee; 4b, 58% ee; 4c, 44% ee) when rubidium fluoride and ferrocenylphosphine ligands bearing monoaza-15-crown-5 (Ib) or monoaza-18-crown-6 (Ic) moieties were used as a base and a chiral ligand, respectively. Optically active allylation product 4a was converted into 1-methyl-1-azaspiro[4.5]-decan-10-amine (13), a precursor to opioid receptor binding agents. Enantioselectivity in the reaction of nitro esters 15 increased in accord with increasing steric demand of the ester alkyl group (Me < Et < t-Bu). The highest selectivity (80% eel for the reaction of tert-butyl ester 15c was observed when the reaction was carried out at -40 degrees C in the presence of the palladium catalyst with the ligand (Ic) bearing a monoaza-18-crown-6 moiety, RbF (2 equiv), and RbClO4 (1 equiv). The pronounced effect of the crown ether moiety for both enantioselection and rate acceleration can be explained by assuming the formation of a ternary complex involving the crown ether, rubidium cation, and enolate anion at the stereodifferentiating transition state. Optically active nitro ester (R)-16c was converted into (R)-alpha-methylglutamic acid (20).

  DOI：

  10.1021/jo961343b
• 作为产物：
  描述：

  2-Methyl-2-nitro-pent-4-enoic acid tert-butyl ester 在 sodium hydroxide 、 9-borabicyclo[3.3.1]nonane dimer 、 双氧水 作用下， 生成 (R)-5-Hydroxy-2-methyl-2-nitro-pentanoic acid tert-butyl ester
  参考文献：
  名称：

  Enantioselective Allylation of Nitro Group-Stabilized Carbanions Catalyzed by Chiral Crown Ether Phosphine−Palladium Complexes

  摘要：

  Enantioselective allylations of alpha-nitro ketones (3) and alpha-nitro esters (15) with allyl acetate were carried out in the presence of 2 equiv of alkali metal fluorides (KF, RbF, CsF) and 1 mol % of palladium catalysts prepared in situ from Pd-2(dba)(3) . CHCl3 and chiral phosphine ligands. Moderate enantioselectivities were observed in the reaction of nitro ketones 3, giving products 4 (4a, 49% ee; 4b, 58% ee; 4c, 44% ee) when rubidium fluoride and ferrocenylphosphine ligands bearing monoaza-15-crown-5 (Ib) or monoaza-18-crown-6 (Ic) moieties were used as a base and a chiral ligand, respectively. Optically active allylation product 4a was converted into 1-methyl-1-azaspiro[4.5]-decan-10-amine (13), a precursor to opioid receptor binding agents. Enantioselectivity in the reaction of nitro esters 15 increased in accord with increasing steric demand of the ester alkyl group (Me < Et < t-Bu). The highest selectivity (80% eel for the reaction of tert-butyl ester 15c was observed when the reaction was carried out at -40 degrees C in the presence of the palladium catalyst with the ligand (Ic) bearing a monoaza-18-crown-6 moiety, RbF (2 equiv), and RbClO4 (1 equiv). The pronounced effect of the crown ether moiety for both enantioselection and rate acceleration can be explained by assuming the formation of a ternary complex involving the crown ether, rubidium cation, and enolate anion at the stereodifferentiating transition state. Optically active nitro ester (R)-16c was converted into (R)-alpha-methylglutamic acid (20).

  DOI：

  10.1021/jo961343b

文献信息

• Enantioselective Allylation of Nitro Group-Stabilized Carbanions Catalyzed by Chiral Crown Ether Phosphine−Palladium Complexes
  作者：Masaya Sawamura、Yuki Nakayama、Wen-Ming Tang、Yoshihiko Ito

  DOI：10.1021/jo961343b

  日期：1996.1.1

  Enantioselective allylations of alpha-nitro ketones (3) and alpha-nitro esters (15) with allyl acetate were carried out in the presence of 2 equiv of alkali metal fluorides (KF, RbF, CsF) and 1 mol % of palladium catalysts prepared in situ from Pd-2(dba)(3) . CHCl3 and chiral phosphine ligands. Moderate enantioselectivities were observed in the reaction of nitro ketones 3, giving products 4 (4a, 49% ee; 4b, 58% ee; 4c, 44% ee) when rubidium fluoride and ferrocenylphosphine ligands bearing monoaza-15-crown-5 (Ib) or monoaza-18-crown-6 (Ic) moieties were used as a base and a chiral ligand, respectively. Optically active allylation product 4a was converted into 1-methyl-1-azaspiro[4.5]-decan-10-amine (13), a precursor to opioid receptor binding agents. Enantioselectivity in the reaction of nitro esters 15 increased in accord with increasing steric demand of the ester alkyl group (Me < Et < t-Bu). The highest selectivity (80% eel for the reaction of tert-butyl ester 15c was observed when the reaction was carried out at -40 degrees C in the presence of the palladium catalyst with the ligand (Ic) bearing a monoaza-18-crown-6 moiety, RbF (2 equiv), and RbClO4 (1 equiv). The pronounced effect of the crown ether moiety for both enantioselection and rate acceleration can be explained by assuming the formation of a ternary complex involving the crown ether, rubidium cation, and enolate anion at the stereodifferentiating transition state. Optically active nitro ester (R)-16c was converted into (R)-alpha-methylglutamic acid (20).