Reducing-Agent-Free Convergent Synthesis of Hydroxyimino-Decorated Tetracyclic Fused Cinnolines via Rh<sup>III</sup>-Catalyzed Annulation Using Nitroolefins
作者:Pidiyara Karishma、Chikkagundagal K. Mahesha、Sanjay K. Mandal、Rajeev Sakhuja
DOI:10.1021/acs.joc.0c02729
日期:2021.2.5
A mild Rh-catalyzed method was developed for the synthesis of hydroxyimino functionalized indazolo[1,2-a]cinnolines and phthalazino[2,3-a]cinnolines by reductive [4 + 2] annulation between 1-arylindazolones and 2-aryl-2,3-dihydrophthalazine-1,4-diones with varied nitroolefins. The targeted oxime decorated tetracyclic fused cinnolines were synthesized via sequential C–H activation/olefin insertion/reduction
开发了一种温和的Rh催化方法,通过还原1-芳基吲唑酮和2-芳基-[4 + 2]环合反应,合成羟基亚氨基官能化的吲唑并[1,2- a ] cinnolines和邻苯并[2,3- a ] cinnolines。 2,3-二氢酞嗪-1,4-二酮与各种硝基烯烃。在无还原剂的条件下,通过连续的C–H活化/烯烃插入/还原反应,合成了目标肟肟修饰的四环稠合肉桂醛。
A Deprotonation Approach to the Unprecedented Amino‐Trimethylenemethane Chemistry: Regio‐, Diastereo‐, and Enantioselective Synthesis of Complex Amino Cycles
作者:Barry M. Trost、Youliang Wang
DOI:10.1002/anie.201805876
日期:2018.8.20
The first realization of the amino‐trimethylenemethane chemistry is reported using a deprotonation strategy to simplify the synthesis of the amino‐trimethylenemethane donor in two steps from commercial and inexpensive materials. A broad scope of cycloaddition acceptors (seven different classes) participated in the chemistry, chemo‐, regio‐, diastereo‐, and enantioselectively generating various types
Dynamic Kinetic Asymmetric Synthesis of Five Contiguous Stereogenic Centers by Sequential Organocatalytic Stetter and Michael−Aldol Reaction: Enantioselective Synthesis of Fully Substituted Cyclopentanols Bearing a Quaternary Stereocenter
作者:Bor-Cherng Hong、Nitin S. Dange、Che-Sheng Hsu、Ju-Hsiou Liao、Gene-Hsiang Lee
DOI:10.1021/ol200006e
日期:2011.3.18
A synthesis of fully substituted cyclopentanes bearing a quaternary carbon center and fivecontiguous stereogenic centers has been achieved by sequential organocatalyzed Stetter and Michael−Aldol reactions of heteroaromatic aldehydes, nitroalkenes, and α,β-unsaturated aldehydes via the [1 + 2 + 2] annulation strategy with dynamic kinetic asymmetric transformation and excellent enantioselectivities
Asymmetric dihydroxylation of vinyl sulfones: routes to enantioenriched α-hydroxyaldehydes and the enantioselective syntheses of furan-2(5H)-ones
作者:Paul Evans、Mélanie Leffray
DOI:10.1016/j.tet.2003.08.003
日期:2003.9
dihydroxylation of α,β-unsaturated sulfones under Sharpless conditions affords enantioenriched α-hydroxyaldehydes in a complex mixture of dimeric species. These mixtures undergo olefination generating the corresponding α,β-unsaturated esters or furan-2(5H)-ones with high levels of enantiomeric excess. The application of this method for the rapid stereoselective synthesis of the furanone natural products; quercus
A series of novel l-proline derived tertiary amine bifunctional organocatalysts 9 are reported, which were applied to the asymmetric Michaeladdition of dithiomalonates 2 to trans-β-nitroolefins 1. The reaction proceeded in high yields (up to 99%) with high enantioselectivities (up to 97% ee). The synthetic utility of this methodology was demonstrated in the short synthesis of (R)-phenibut in high