Author
Young Eun Lee
Other affiliations: UPRRP College of Natural Sciences
Bio: Young Eun Lee is an academic researcher from University of Pennsylvania. The author has contributed to research in topics: Radical cyclization & Honokiol. The author has an hindex of 4, co-authored 8 publications receiving 203 citations. Previous affiliations of Young Eun Lee include UPRRP College of Natural Sciences.
Topics: Radical cyclization, Honokiol, Salt (chemistry), Diene, Carboxylic acid
Papers
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TL;DR: Simple catalysts that use atom-economical oxygen as the terminal oxidant to accomplish selective ortho–ortho, ortho-para, or para–para homo-couplings of phenols are described.
Abstract: Simple catalysts that use atom-economical oxygen as the terminal oxidant to accomplish selective ortho–ortho, ortho–para, or para–para homo-couplings of phenols are described. In addition, chromium salen catalysts have been discovered as uniquely effective in the cross-coupling of different phenols with high chemo- and regioselectivity.
140 citations
TL;DR: (+)-SCH 351448 (Na+ salt A) was synthesized employing ring-closing olefin metathesis reaction of an open diene diester intermediate for construction of the 28-membered macrodiolide structure under acidic conditions, but SCH 35 1448 (Ca2+ salt) and (Na- salt B) appear to be physiologically important species.
Abstract: (+)-SCH 351448 (Na+ salt A) was synthesized employing ring-closing olefin metathesis reaction of an open diene diester intermediate for construction of the 28-membered macrodiolide structure. The open diene diester was prepared from the monomeric hydroxy carboxylic acid and two different olefin fragments. The monomeric hydroxy acid was synthesized via Julia−Julia coupling reaction of intermediates derived from the same olefinic fragments. Oxane units in these fragments were prepared by radical cyclization reactions of β-alkoxyacrylates. Analogous SCH 351448 salts incorporating other mono- and divalent cations may be prepared. Under acidic conditions, SCH 351448 (Na+ salt A) was the most stable complex, but SCH 351448 (Ca2+ salt) and (Na+ salt B) appear to be physiologically important species.
51 citations
TL;DR: Stereoselective synthesis of (+)-monocerin was accomplished via radical cyclization of a vinylic ether intermediate.
22 citations
TL;DR: In this paper, simple catalysts that use atom-economical oxygen as the terminal oxidant to accomplish selective ortho-ortho, orthopara, or para-para homo-couplings of phenols are described.
Abstract: Simple catalysts that use atom-economical oxygen as the terminal oxidant to accomplish selective ortho–ortho, ortho–para, or para–para homo-couplings of phenols are described. In addition, chromium salen catalysts have been discovered as uniquely effective in the cross-coupling of different phenols with high chemo- and regioselectivity.
6 citations
Patent•
21 Oct 2016
TL;DR: In this paper, improved methods for the synthesis of honokiol, as well as methods for 3,3'-di-tert-butyl-5,5'-dimethyl-[1,1'-biphenyl]-2,4'-diol, 3',5-dimethyl]-1, 1-biphensyl-2, 4-diol and 2.4'-dimethoxy-3',5dimethyl-1-1"-biphetyl-1, bisphenyl, were presented.
Abstract: Disclosed herein are improved methods for the synthesis of honokiol, as well as methods for the synthesis of 3,3'-di-tert-butyl-5,5'-dimethyl-[1,1'-biphenyl]-2,4'-diol, 3',5-dimethyl-[1,1'-biphenyl]-2,4'-diol, and 2,4'-dimethoxy-3',5-dimethyl-1,1'-biphenyl, 3,3',5,5'-tetra-tert-butyl-[1,1'-biphenyl]-2,4'-diol, and certain tetrasubstituted bisphenols, and uses therefor.
1 citations
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832 citations
TL;DR: This paper aims to demonstrate the efforts towards in-situ applicability of EMMARM, as to provide real-time information about concrete mechanical properties such as E-modulus and compressive strength.
Abstract: We thank the Spanish Ministerio de Ciencia e Innovacion (Grant Nos. CTQ2007-65218 and Consolider Ingenio 2010-CSD-2007-00006 and CTQ2011-24165), the Generalitat Valenciana (Grant No. PROMETEO/2009/039 and FEDER), and the University of Alicante for generous and continuous financial support.
403 citations
TL;DR: A DFT calculation indicates that Mn catalyst plays key dual roles as an efficient catalyst for the generation of azido radical and a stabilizer for peroxyl radical intermediate, which provides a novel approach to high value-added β-azido alcohols.
Abstract: An efficient Mn-catalyzed aerobic oxidative hydroxyazidation of olefins for synthesis of β-azido alcohols has been developed. The aerobic oxidative generation of azido radical employing air as the terminal oxidant is disclosed as the key process for this transformation. The reaction is appreciated by its broad substrate scope, inexpensive Mn-catalyst, high efficiency, easy operation under air, and mild conditions at room temperature. This chemistry provides a novel approach to high value-added β-azido alcohols, which are useful precursors of aziridines, β-amino alcohols, and other important N- and O-containing heterocyclic compounds. This chemistry also provides an unexpected approach to azido substituted cyclic peroxy alcohol esters. A DFT calculation indicates that Mn catalyst plays key dual roles as an efficient catalyst for the generation of azido radical and a stabilizer for peroxyl radical intermediate. Further calculation reasonably explains the proposed mechanism for the control of C-C bond cleavage or for the formation of β-azido alcohols.
234 citations
TL;DR: The Julia-Kocienski reaction has become indispensable in the synthetic organic chemist's olefination toolbox as discussed by the authors, although the stereochemical outcome of the transformation is sometimes difficult to predict.
231 citations