<(1S)-1-methyl-2-phenylethyl>methoxymethylborane | 133524-06-8

• 分子结构分类: 有机化合物
• 英文名称: <(1S)-1-methyl-2-phenylethyl>methoxymethylborane
• 英文别名: methoxy-methyl-[(2S)-1-phenylpropan-2-yl]borane
• CAS: 133524-06-8
• 化学式: C₁₁H₁₇BO
• 分子量: 176.066
• InChiKey: ZBOLGWYQMIICNV-JTQLQIEISA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.89
• 重原子数：
  13
• 可旋转键数：
  4
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.45
• 拓扑面积：
  9.2
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  1,1-二氯甲醚 、 <(1S)-1-methyl-2-phenylethyl>methoxymethylborane 在 双氧水 、 lithium tert-butoxide 作用下， 生成 (3S)-3-methyl-4-phenylbutan-2-one
  参考文献：
  名称：

  Chiral synthesis via organoboranes. 30. Facile synthesis, by the Matteson asymmetric homologation procedure, of .alpha.-methyl boronic acids not available from asymmetric hydroboration and their conversion into the corresponding aldehydes, ketones, carboxylic acids, and amines of high enantiomeric purity

  摘要：

  2-(alpha-Methylalkyl)- or 2-(alpha-arylethyl)-1,3,2-dioxaborinanes, RMeHC*BO2(CH2)3 (R = alkyl or aryl), of very high enantiomeric purity, not available from asymmetric hydroboration, can be prepared by the Matteson asymmetric homologation procedure of optically pure pinanediol or 2,3-butanediol boronate esters with (dichloromethyl)lithium, LiCHCl2, conveniently generated in situ in THF at -78-degrees-C, followed by reaction with either a Grignard reagent or an alkyllithium, with subsequent removal of the chiral auxiliaries. alpha-Methyl boronic esters thus obtained are readily converted into the corresponding aldehydes by the reaction with [methoxy(phenylthio)methyl]lithium [LiCH(OMe)SPh] (MPML) and mercuric chloride, followed by oxidation with hydrogen peroxide in a pH 8 buffer medium. The two-phase aqueous chromic acid procedure can be used to oxidize these aldehydes to the corresponding alpha-methyl carboxylic acids of very high enantiomeric purity without significant racemization. Additionally, pinanediol or 2,3-butanediol alpha-methylorganylboronate esters can be conveniently converted into borinic ester derivatives, RMeHC*BMe(OMe), of very high enantiomeric purity by reaction with methyllithium, followed by treatment with methanolic hydrogen chloride and subsequent recovery of the valuable chiral auxiliaries. These borinic ester derivatives are converted into alpha-methyl ketones and alpha-methyl primary amines of known absolute configuration by the alpha,alpha-dichloromethyl methyl ether (DCME) reaction and the reaction with hydroxylamine-O-sulfonic acid, respectively. The present synthesis of chiral 2-organyl-1,3,2-dioxaborinanes by the Matteson route, together with our direct asymmetric hydroboration procedure, makes it possible to synthesize many chiral boronic acid derivatives in very high enantiomeric purities. These complementary procedures greatly expand the scope of asymmetric synthesis via chiral organoboranes.

  DOI：

  10.1021/jo00010a022