Enantioselective (Formal) Aza-Diels−Alder Reactions with Non-Danishefsky-Type Dienes
作者:Uttam K. Tambar、Sharon K. Lee、James L. Leighton
DOI:10.1021/ja104480g
日期:2010.8.4
Enantioselective (formal) aza-Diels-Alderreactions between acylhydrazones and non-Danishefsky-type dienes have been developed. The reactions are promoted by a simple and economical chiral silicon Lewis acid and are typically conducted at ambient temperature. Both glyoxylate- and aliphatic aldehyde-derived hydrazones may be employed, as may variously substituted dienes, leading to the synthesis of
The cross-coupling reactions of 2-(1,3-butadienyl)magnesium chloride (1) with aryl and alkyl iodides were investigated in the presence of transition metal catalysts. Tetrakis(triphenylphosphine)pal...
Dehydrogenative Aza-[4 + 2] Cycloaddition of Amines with 1,3-Dienes via Dual Catalysis
作者:Xiaoxiao Chen、Guoxiang Zhang、Rong Zeng
DOI:10.1021/acs.orglett.1c02558
日期:2021.9.17
We describe a synergistic utilization of copper catalysis and proton-transfer catalysis that enables an atom- and step-economical aza-[4 + 2] cycloaddition reaction of readily available N-arylamino carbonyl compounds with simple 1,3-dienes. The reaction proceeds smoothly under an air atmosphere and produces water as the sole side product. Whereas the amines can directly serve as the C- and N-atom donors
我们描述了铜催化和质子转移催化的协同利用,使容易获得的N-芳基氨基羰基化合物与简单的 1,3-二烯进行原子和步骤经济的氮杂-[4 + 2] 环加成反应。反应在空气气氛下顺利进行,并产生水作为唯一的副产物。虽然胺可以直接作为 C 和 N 原子供体,但这种操作简单的方案提供了绿色、快速和高效的 1,2,3,6-四氢吡啶,范围广泛。
Enantioselective Formation of All-Carbon Quaternary Centers via C–H Functionalization of Methanol: Iridium-Catalyzed Diene Hydrohydroxymethylation
作者:Khoa D. Nguyen、Daniel Herkommer、Michael J. Krische
DOI:10.1021/jacs.6b09333
日期:2016.11.2
enantioselective C-C couplings of methanol (>30 × 106 tons/year) are reported. Insertion of 2-substituted dienes into the methanol C-H bond occurs in a regioselective manner to form all-carbon quaternarycenters with excellent levels of enantioselectivity using an iridium-PhanePhos catalyst. Mechanistic studies corroborate a Curtin-Hammett scenario in which methanol dehydrogenation triggers rapid, reversible
Carbonylation reactions constitute important methodologies for the synthesis of all kinds of carboxylic acid derivatives. The development of novel and efficient catalysts for these transformations is of interest for both academic and industrial research. Here, the first palladium-based catalyst system for the aminocarbonylation of 1,3-dienes is described. This atom-efficient transformation proceeds