Nucleophilic reactions of fluoroolefins.IV. Regioselectivity in the reactions of 1-phenylpentafluoropropenes with alkyllithium reagents
作者:Wojciech Dmowski
DOI:10.1016/s0022-1139(00)80925-2
日期:1984.10
steric constants was found. Overall regioselectivity, in the reaction of 1-phenylpentafluoropropenes 1 with alkyllithiumreagents, considering both the influence of the benzene ring substituents and steric factors, is expressed by the Pavelich-Taft type equation. Observed direction of the influence of the bulk of the alkyllithiumreagents on the ratio of products 2 and 3 is interpreted in terms of steric
详细研究了1-苯基五氟丙烯1a – c与许多烷基锂试剂的反应。在所有情况下,均得到1-烷基-1-苯基四氟丙烯2和2-烷基-1-苯基四氟丙烯3的混合物。产物2和3的比例受苯环取代基的电负性和烷基锂试剂的大部分烷基的强烈影响。这两个因素的增加有利于2-烷基取代的烯烃3的形成,而1-烷基取代的烯烃2的产率降低。烯烃1中苯环取代基的影响服从哈米特类型相关性,而烯烃1的影响遵循哈米特类型相关性。烷基锂试剂的大部分与空间替代常数E x s的Fellous和Luft标度显示出良好的关系; 没有发现与其他空间常数的线性相关。考虑到苯环取代基的影响和位阻因素,在1-苯基五氟丙烯1与烷基锂试剂反应中的总体区域选择性由Pavelich-Taft型方程表示。观察到的烷基锂试剂的大部分对产物2和3的比率的影响的方向是根据影响这些反应中所涉及的中间体的几何形状和自由能的空间应变来解释的。
Nucleophilic reaction of fluoroolefins. V. Regioselectivity and stereochemistry in the reactios of 1-phenylpentafluoropropenes with lithium dialkylamides
作者:Wojciech Dmowski
DOI:10.1016/s0022-1139(00)80938-0
日期:1984.11
alkenes and 2-amino-substituted alkenes , with the latter being the favoured products. The reactions with bulky lithium diethylamide and lithium 2-methylpiperidinoamide gave exclusively 1-amino-substituted products . The effect of the increased bulk of N-nucleophiles is opposite to that observed for the reactions of alkenes with C-nucleophiles Increasing electronegativity of the phenyl ring substituents
Nucleophilic reactions of fluoroolefins. II. Regioselectivity and elimination-addition competition in the reaction of 1-phenylpentafluoropropenes with sodium ethoxide
作者:Wojciech Dmowski
DOI:10.1016/s0022-1139(00)81242-7
日期:1982.10
1-Phenylpentafluoropropene and its para-substituted analogs are susceptible to nucleophilic attack at both vinylic carbon atoms C-1 and C-2. They react with ethanolio sodium ethoxide to give predominantly substitution products, 1-ethoxy-1-phenyltetrafluoropropenes and 2-ethoxy-1-phenyltetrafluoropropenes , with only little formation of adducts, . 2-ethoxy-1H-1-phenylpentafluoropropanes . Alkenes ,