Stereoselective synthesis of functionalised cyclopropanes from nitroalkenes via an organocatalysed Michael-initiated ring-closure approach
摘要:
Synthetically useful nitrocyclopropanes are easily obtained via Michael addition of dimethyl bromomalonate to nitrostyrenes promoted by commercially available (S)-alpha,alpha-di-beta-naphthlyl-2-pyrrolidinemethanol as the catalyst, followed by DABCO-mediated intramolecular nucleophilic substitution. The functionalised nitrocyclopropanes are obtained in good yield, excellent diastereoselectivity and up to 49% ee. (C) 2010 Elsevier Ltd. All rights reserved.
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
Iodobenzene-Catalyzed Oxidative Cyclization for the Synthesis of Highly Functionalized Cyclopropanes
作者:Yang Li、Hao Guo、Renhua Fan
DOI:10.1055/s-0039-1690809
日期:2020.3
iodobenzene-catalyzed oxidative cyclization of Michael adducts of activated methylene compounds with nitroolefins or chalcones is developed. mCPBA is used as oxidant together with Bu4NI for the generation of a highly reactive iodine(III) species to mediate the cyclopropanation via a ligand exchange and reductive elimination process. A range of highly functionalized cyclopropanes are synthesized with
Stereoselective Synthesis of Highly Functionalized Nitrocyclopropanes via Organocatalyic Conjugate Addition to Nitroalkenes
作者:Séamus H. McCooey、Thomas McCabe、Stephen J. Connon
DOI:10.1021/jo0613838
日期:2006.9.1
A convenient and novel one-pot organocatalytic methodology for the stereoselectivesynthesis of highly functionalized nitrocyclopropanes is reported. The addition of dimethyl chloromalonate to a variety of nitroolefins catalyzed by tertiary amines leads to a Michaeladduct which cyclizes to form the cyclopropane in the presence of DBU under carefully controlled reaction conditions with outstanding
Highly Enantioselective Synthesis of Nitrocyclopropanes via Organocatalytic Conjugate Addition of Bromomalonate to α,β-Unsaturated Nitroalkenes
作者:Yi-ning Xuan、Shao-zhen Nie、Li-ting Dong、Jun-min Zhang、Ming Yan
DOI:10.1021/ol900227j
日期:2009.4.2
Highly enantioselectivesynthesis of nitrocyclopropanes was achieved via the organocatalytic conjugate addition of dimethyl bromomalonate to nitroalkenes and the consequent intramolecular cyclopropanation. 6′-Demethyl quinine was found to be the efficient catalyst. Excellent enantioselectivities, diastereoselectivities, and good yields were obtained for a variety of aryl or heteroaryl nitroethylenes