Liu, Zengjin Lin, Xinglong Yang, Na Su, Zhishan Hu, Changwei Xiao, Peihong He, Yanyang Song, Zhenlei Unique Steric Effect of Geminal Bis(silane) To Control the High <i>Exo</i>-selectivity in Intermolecular Diels–Alder Reaction The unique steric effect of geminal bis­(silane) [(R<sub>3</sub>Si)<sub>2</sub>CH] allows an <i>exo</i>-selective intermolecular Diels–Alder reaction of geminal bis­(silyl) dienes with α,β-unsaturated carbonyl compounds. The approach shows good generality to form <i>ortho</i>–<i>trans</i> cyclohexenes in good yields with high <i>exo</i>-selectivity and high enantioselectivity in some asymmetric cases. The excellent <i>exo</i>-stereocontrol aptitude of (R<sub>3</sub>Si)<sub>2</sub>CH group is highlighted by comparing with R<sub>3</sub>SiCH<sub>2</sub> and R<sub>3</sub>Si groups, which leads to <i>endo</i>-selectivity predominantly. The conformational analysis of dienes suggests that (R<sub>3</sub>Si)<sub>2</sub>CH group effectively shields both sides of the diene moiety, ensuring the desired <i>exo</i>-selectivity. Moreover, the geminal bis­(silane) can be further functionalized to transform the resulting <i>ortho</i>–<i>trans</i> cycloadducts into useful synthons, which makes the approach hold great potential for organic synthesis. steric effect;R 3Si groups;carbonyl compounds;Diel;approach;R 3Si group;diene moiety;Unique Steric Effect;bi;R 3SiCH;ortho;geminal 2016-01-22
    https://acs.figshare.com/articles/dataset/Unique_Steric_Effect_of_Geminal_Bis_silane_To_Control_the_High_i_Exo_i_selectivity_in_Intermolecular_Diels_Alder_Reaction/2072167
10.1021/jacs.5b09689.s002