<scp>β‐Nitrostyrenes</scp>
as a valuable precursor for the synthesis of β‐aryl‐γ‐lactam and 2‐oxo‐1,2‐dihydroquinoline derivatives
作者:Dandamudi V. Lenin、Disha Patel、Payal Malvi
DOI:10.1002/jhet.4446
日期:2022.3
2-dihydroquinoline derivatives using β-nitrostyrenes. The reaction strategy involves the Michaeladdition followed by reduction and cyclization reactions. Michael adducts containing two different nitro group such as one on aryl ring and another on side chain, selectively takes the path to involve nitro group on aryl to form 2-oxo-1,2-dihydroquinoline derivatives as cyclized product. Michael adducts with
progress has been made toward the development of metal-free catalysts of enantioselective transformations, yet the discovery of organic catalysts effective at low catalyst loadings remains a major challenge. Here we report a novel synergistic catalyst combination system consisting of a peptide-inspired chiral helical (thio)urea oligomer and a simple tertiary amine that is able to promote the Michael reaction
Divergent Reactivity of Nitrocyclopropanes with Huisgen Zwitterions and Facile Syntheses of 3-Alkoxy Pyrazolines and Pyrazoles
作者:Changjiang Yang、Wei Liu、Zijian He、Zhengjie He
DOI:10.1021/acs.orglett.6b02415
日期:2016.10.7
A novel annulation reaction of trans-2-substituted-3-nitrocyclopropane-1,1-carboxylates with in situ generated Huisgen zwitterions is reported, providing facile synthesis of 3-alkoxy pyrazolines in good yields and high diastereoselectivities. This reaction unveils the divergent reactivity of the nitrocyclopropanes as a kind of versatile donor–acceptor cyclopropanes. It is also demonstrated that the
Highly Enantioselective Michael
Addition of Malonates to Nitroolefins Catalyzed by Chiral
Bifunctional Tertiary Amine-Thioureas Based on Saccharides
作者:Jun-An Ma、Xiao-Juan Li、Kun Liu、Hai Ma、Jing Nie
DOI:10.1055/s-0028-1087370
日期:——
A series of saccharide-derived bifunctional tertiary amine-thioureas for the asymmetric Michaeladdition reaction have been designed and synthesized. The addition products between malonates and various nitroolefins were obtained in high yields (up to 99%) and excellentenantioselectivities (up to 99% ee).
Iodine-Promoted Synthesis of 3-Arylindolizine-1-Carboxylates from 2-(2-Nitro-1-Arylethyl)Malonates and Pyridine
作者:Yun Li、Zhengquan Zhou、Weijian Ye、Juanjuan Liu、Juan Yao、Cunde Wang
DOI:10.3184/174751913x13737205567934
日期:2013.9
An efficient and straightforward one-pot synthetic protocol has been developed for the synthesis of 3-arylindolizine-1-carboxylates via 1,3-dipolar annulation of 2-(2-nitro-1-arylethyl)malonates with pyridine and subsequent aromatisation in the presence of molecular iodine. The structure of methyl 3-(4-methoxyphenyl)indolizine-1-carboxylate (2a) and methyl 3-iodo-2-(4-nitrophenyl)indolizine-1-carboxylate