Nucleophilic Additions to Alkylidene Bis(sulfoxides)—Stereoelectronic Effects in Vinyl Sulfoxides
作者:Tobias Wedel、Timo Gehring、Joachim Podlech、Elena Kordel、Angela Bihlmeier、Wim Klopper
DOI:10.1002/chem.200701847
日期:2008.5.19
Conjugate additions of nucleophiles (e.g. enolates, amines and malonate anions) to bis(p-tolylsulfinyl)alkenes, alkylidene-1,3-dithiane-1,3-dioxides and alkylidene-1,3-dithiolane-1,3-dioxides have recently been published. Reasons for different selectivities and reaction rates will be discussed by consideration of steric and electronic effects. The preferred mode of attack can be explained by stereoelectronic
将亲核试剂(例如,烯酸酯,胺和丙二酸根阴离子)共轭添加到双(对甲苯基亚磺酰基)烯烃,亚烷基-1,3-二硫代-1,3-二氧化物和亚烷基-1,3-二硫代-1,3-二氧化物中最近已出版。将通过考虑空间效应和电子效应来讨论选择性和反应速率不同的原因。首选的攻击方式可以通过主要碳负离子中的立体电子效应(超共轭)来解释,该作用通过n-> SO-sigma *与反周平面S = O基团的相互作用来稳定。将丙酮烯酸酯添加至二噻烷衍生的亚烷基双(亚砜)的过渡态[BP86 / aug-TZVP]的计算表明,攻击所需的能量更多,为6.6-7.3 kJ mol(-1),从而减少了稳定的碳负离子。