Willis Michael C, Randell-Sly Helen E, Woodward Robert L, McNally Steven J, Currie Gordon S
Department of Chemistry, University of Bath, Bath BA2 7AY, UK.
J Org Chem. 2006 Jul 7;71(14):5291-7. doi: 10.1021/jo060582o.
The use of beta-S-substituted aldehydes in rhodium-catalyzed intermolecular hydroacylation reactions is reported. Aldehydes substituted with either sulfide or thioacetal groups undergo efficient hydroacylation with a variety of electron-poor alkenes, such as enoates, in Stetter-like processes and with both electron-poor and neutral alkynes. In general, the reactions with electron-poor alkenes demonstrate good selectivity for the linear regioisomer, and the reactions with alkynes provide enone products with excellent selectivity for the E-isomers. The scope of the process was shown to be broad, tolerating a variety of substitution patterns and functional groups on both reaction components. A novel CN-directing effect was shown to be responsible for reversing the regioselectivity in a number of alkyne hydroacylation reactions. Catalyst loadings as low as 0.1 mol % were achievable.
报道了β-S-取代醛在铑催化的分子间氢酰化反应中的应用。被硫化物或硫代缩醛基团取代的醛在类施陶丁格反应过程中能与多种缺电子烯烃（如烯酸酯）以及缺电子和中性炔烃高效地发生氢酰化反应。一般来说，与缺电子烯烃的反应对线性区域异构体表现出良好的选择性，与炔烃的反应则为E-异构体的烯酮产物提供了优异的选择性。该反应过程的适用范围很广，两种反应组分上的各种取代模式和官能团都能兼容。在许多炔烃氢酰化反应中，一种新的氰基导向效应被证明是导致区域选择性反转的原因。催化剂负载量低至0.1 mol%即可实现。
