描述了一种温和且操作简单的铜催化乙烯基有氧氧化 β,γ-和 α,β-不饱和酯。该方法具有收率好、底物范围广、化学选择性和区域选择性好、官能团耐受性好等特点。该方法还能够氧化β,γ-和α,β-不饱和醛、酮、酰胺、腈和砜。此外,本催化体系适用于双乙烯基和三乙烯基氧化。发现四甲基胍 (TMG) 作为碱的作用至关重要,但我们也推测它可以作为三氟甲磺酸铜 (II) 的配体来生产活性铜 (II) 催化剂。进行的机械实验表明,通过烯丙基铜 (II) 物质存在一个合理的反应途径。最后,
bearing cyanomethyl, acetamide, and N,N-dimethylacetamide groups were examined for Wittig type reactions. All three reacted to give the corresponding olefins. The reaction of the cyanomethyl reagent with aldehydes gave α,β-unsaturated cyanides with high Z-selectivity in the case of aliphatic aldehydes (Z:E=94:6 to 99:1). On the other hand, the reactions of the two amide reagents with aldehydes yielded
[GRAPHICS]The Peterson reaction between (t-BuO)Ph2SiCH2CN and various aidehydes furnishes the corresponding beta-monosubstituted alpha,beta-unsaturated cyanides with high Z selectivity (Z:E = 92:8 to > 98:2).
A Facile, One-Pot Synthesis of β-Substituted (<i>Z</i>)-Acrylonitriles Utilizing an α-Diaminoboryl Carbanion
作者:Takashi Tomioka、Yusuke Takahashi、Trey G. Vaughan、Takayoshi Yanase
DOI:10.1021/ol100534s
日期:2010.5.21
A simple three-step single-pot procedure for Z-stereoselective synthesis of beta-monosubstituted acrylonitriles has been established. The reaction involves olefination of aldehydes with an in situ generated alpha-diaminoboryl carbanion species. Various aromatic and aliphatic aldehydes were smoothly converted into the corresponding (Z)-olefin products (up to 96:4 ratio) in good yields (80-98%).
ETEMAD-MOGHADAM, G.;SEYDEN-PENNE, J., SYNTH. COMMUN., 1984, 14, N 6, 565-573