Regioselectivity Switch in Palladium‐Catalyzed Allenylic Cycloadditions of Allenic Esters: [4+1] or [4+3] Cycloaddition/Cross‐Coupling
作者:Long Li、Pengfei Luo、Yuhua Deng、Zhihui Shao
DOI:10.1002/anie.201901511
日期:2019.3.26
The first Pd‐catalyzed asymmetric allenylic [4+1] cycloaddition was successfully developed. Alternatively, tuning the Pd catalyst switched the reactivity toward an unprecedented [4+3] cycloaddition/cross‐coupling. Ligands play a vital role in controlling the reaction pathway, allowing highly selective access to different products from identical substrates. Biological evaluation of the obtained compounds
A new and efficient catalytic strategy that combines asymmetric organocatalysis and iodine catalysis was first developed for the one-pot Michael/iodization/SN2 nucleophilic substitution sequentialcatalyticsynthesis of spirodihydrobenzofuran pyrazolones and spirodihydrobenzofuran oxindoles. The approach results in products with moderate to high yields (up to 93%), high to excellent enantioselectivities
An efficient synthetic strategy for the unique class of pyrazolo[1,2‐a]cinnolines was developed through a rhodium‐catalyzed oxidativecoupling of N‐aryl‐1H‐pyrazol‐5(4H)‐ones with internal alkynes. This protocol features use of the pyrazolone function in the substrate as an intrinsic directing group, hexafluoroisopropyl alcohol (HFIP) as the solvent, and mild reaction conditions as well as a wide substrate
为唯一的类吡唑并的有效的合成策略[1,2一]噌啉通过的铑催化的氧化偶合开发ñ -芳基- 1 H ^ -吡唑-5-(4 ħ) -酮与内部炔烃。该方案的特征是在底物中使用吡唑啉酮功能作为固有的导向基团,在溶剂中使用六氟异丙醇(HFIP),反应条件温和,并且底物范围广。