http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hong, Suckchang,Kim, Minsik,Jung, Myunggi,Ha, Min Woo,Lee, Myungmo,Park, Yohan,Kim, Mi-hyun,Kim, Taek-Soo,Lee, Jihoon,Park, Hyeung-geun The Royal Society of Chemistry 2014 Organic & Biomolecular Chemistry Vol.12 No.9
<P>A new enantioselective synthetic method for α-halo-α-alkylmalonates is reported. α-Alkylation of diphenylmethyl <I>tert</I>-butyl α-halomalonates under phase-transfer catalytic conditions (solid KOH, toluene, −40 °C) in the presence of (<I>S</I>,<I>S</I>)-3,4,5-trifluorophenyl-NAS bromide (5 mol%) afforded diphenylmethyl <I>tert</I>-butyl α-halo-α-alkylmalonates in very high chemical yields (up to 99%) and optical yields (up to 93% ee).</P> <P>Graphic Abstract</P><P>A new enantioselective synthetic method for α-halo-α-alkylmalonates is reported. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3ob42107d'> </P>
Total Synthesis of Swinholide A: An Exposition in Hydrogen-Mediated C–C Bond Formation
Shin, Inji,Hong, Suckchang,Krische, Michael J. American Chemical Society 2016 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.138 No.43
<P>Diverse hydrogen-mediated C–C couplings enable construction of the actin-binding marine polyketide swinholide A in only 15 steps (longest linear sequence), roughly half the steps required in two prior total syntheses. The redox-economy, chemo- and stereoselectivity embodied by this new class of C–C couplings are shown to evoke a step-change in efficiency.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2016/jacsat.2016.138.issue-43/jacs.6b10645/production/images/medium/ja-2016-10645f_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja6b10645'>ACS Electronic Supporting Info</A></P>
Enantioselective phase-transfer catalytic α-alkylation of 2-methylbenzyl <i>tert</i>-butyl malonates
Ha, Min Woo,Hong, Suckchang,Park, Cheonhyoung,Park, Yohan,Lee, Jihye,Kim, Mi-hyun,Lee, Jihoon,Park, Hyeung-geun The Royal Society of Chemistry 2013 Organic & biomolecular chemistry Vol.11 No.24
<P>A new asymmetric synthetic method to prepare alpha,alpha-dialkylmalonates for the construction of a quaternary carbon center via phase-transfer catalytic (PTC) alkylation has been developed. Enantioselective alpha-alkylation of 2-methylbenzyl tert-butyl alpha-methylmalonates under phase-transfer catalytic conditions in the presence of (S,S)-3,4,5-trifluorophenyl-NAS bromide (10) afforded the corresponding alpha,alpha-dialkylmalonates in high chemical (up to 99%) and optical yields (up to 91% ee), which were selectively hydrolyzed to malonic monoacids under alkali basic conditions for conversion to versatile chiral intermediates.</P>
Highly Enantioselective Total Synthesis of (+)-Isonitramine
Park, Yohan,Lee, Young Ju,Hong, Suckchang,Lee, Myungmo,Park, Hyeung-geun American Chemical Society 2012 Organic letters Vol.14 No.3
<P>A new efficient enantioselective synthetic method of (+)-isonitramine is reported. (+)-Isonitramine was obtained in 12 steps (98% ee and 43% overall yield) from δ-valerolactam <I>via</I> enantioselective phase-transfer catalytic alkylation, Dieckman condensation, and diastereoselective reduction as key steps.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2012/orlef7.2012.14.issue-3/ol2033042/production/images/medium/ol-2011-033042_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol2033042'>ACS Electronic Supporting Info</A></P>
Kim, Doyoung,Ha, Min Woo,Hong, Suckchang,Park, Cheonhyoung,Kim, Byungsoo,Yang, Jewon,Park, Hyeung-geun American Chemical Society 2017 Journal of organic chemistry Vol.82 No.9
<P>A new efficient synthetic method for chiral alpha-azido-alpha-alkylmalonates and alpha-aryloxy-alpha-alkylmalonates was developed. The enantioselective alpha-alkylation of diphenylmethyl tert-butyl alpha-bromomalonate under phase-transfer catalytic conditions [(S,S)-3,4,5-trifluorophenyl-NAS bromide, 50% KOH, toluene, and -40 degrees C) provided the corresponding alpha-bromo-alpha-alkylmalonates in high chemical yields (<= 98%) and high optical yields (<= 99% ee). The resulting alpha-alkylated products were converted to alpha-azido-alpha-alkylmalonates <= 97% ee) and alpha-aryloxy-alpha-alkylmalonates (<= 79%, <= 93%, ee) by S(N)2 substitution with sodium azide and aryloxides, respectively.</P>
Lee, Myungmo,Lee, Young-Ju,Park, Eunyoung,Park, Yohan,Ha, Min Woo,Hong, Suckchang,Lee, Yeon-Ju,Kim, Taek-Soo,Kim, Mi-hyun,Park, Hyeung-geun The Royal Society of Chemistry 2013 Organic & biomolecular chemistry Vol.11 No.12
<P>An efficient enantioselective synthetic method for the synthesis of (2<I>R</I>)-5-phenyl-2-alkylproline <I>tert</I>-butyl esters was reported. The phase-transfer catalytic alkylation of <I>tert</I>-butyl-5-phenyl-3,4-dihydro-2<I>H</I>-pyrrole-2-carboxylate in the presence of chiral quaternary ammonium catalysts gave the corresponding alkylated products (up to 97% ee). The following diastereoselective reductions afforded chiral 5-phenyl-2-alkylprolines which can be applied to asymmetric synthesis as organocatalysts or synthesis of biologically active proline based compounds, such as chiral α-alkylated analogues of (+)-RP66803, as potential CCK antagonists.</P> <P>Graphic Abstract</P><P>An efficient enantioselective synthetic method for the synthesis of (2<I>R</I>)-5-phenyl-2-alkylproline <I>tert</I>-butyl esters was reported. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3ob27089k'> </P>
Han, Yong-Hyun,Kim, Hyeon-Ji,Kim, Eun-Jin,Kim, Kyu-Seo,Hong, Suckchang,Park, Hyeung-Geun,Lee, Mi-Ock Mary Ann Liebert, Inc 2014 ANTIOXIDANTS AND REDOX SIGNALING Vol.21 No.15
<P>Increased hepatic oxidative stress and inflammation is the main cause of exacerbating nonalcoholic steatohepatitis (NASH). Retinoic acid-related orphan receptor α (RORα) regulates diverse target genes associated with lipid metabolism, and its expression level is low in the liver of patients with NASH. Here, we investigated the role of RORα in regulating hepatic oxidative stress and inflammation.</P>
Kim, Eun‐,Jin,Yoon, Young‐,Sil,Hong, Suckchang,Son, Ho‐,Young,Na, Tae‐,Young,Lee, Min‐,Ho,Kang, Hyun‐,Jin,Park, Jinyoung,Cho, Won‐,Jea,Kim, Sang‐,Gun,Ko Wiley Subscription Services, Inc., A Wiley Company 2012 Hepatology Vol.55 No.5
<P><B>Abstract</B></P><P>There is increasing evidence that the retinoic acid receptor–related orphan receptor α (RORα) plays an important role in the regulation of metabolic pathways, particularly of fatty acid and cholesterol metabolism; however, the role of RORα in the regulation of hepatic lipogenesis has not been studied. Here, we report that RORα attenuates hepatic steatosis, probably via activation of the adenosine monophosphate (AMP)‐activated protein kinase (AMPK) and repression of the liver X receptor α (LXRα). First, RORα and its activator, cholesterol sulfate (CS), induced phosphorylation of AMPK, which was accompanied by the activation of serine–threonine kinase liver kinase B1 (LKB1). Second, the activation of RORα, either by transient transfection or CS treatment, decreased the TO901317‐induced transcriptional expression of LXRα and its downstream target genes, such as the sterol regulatory element binding protein‐1 (SREBP‐1) and fatty acid synthase. RORα interacted physically with LXRα and inhibited the LXRα response element in the promoter of LXRα, indicating that RORα interrupts the autoregulatory activation loop of LXRα. Third, infection with adenovirus encoding RORα suppressed the lipid accumulation that had been induced by a free‐fatty–acid mixture in cultured cells. Furthermore, we observed that the level of expression of the RORα protein was decreased in the liver of mice that were fed a high‐fat diet. Restoration of RORα via tail‐vein injection of adenovirus (Ad)‐RORα decreased the high‐fat‐diet–induced hepatic steatosis. Finally, we synthesized thiourea derivatives that activated RORα, thereby inducing activation of AMPK and repression of LXRα. These compounds decreased hepatic triglyceride levels and lipid droplets in the high‐fat‐diet–fed mice. <I>Conclusion</I>: We found that RORα induced activation of AMPK and inhibition of the lipogenic function of LXRα, which may be key phenomena that provide the beneficial effects of RORα against hepatic steatosis. (H<SMALL>EPATOLOGY</SMALL> 2012;)</P>
Ha, Min Woo,Lee, Myungmo,Choi, Sujee,Kim, Seek,Hong, Suckchang,Park, Yohan,Kim, Mi-hyun,Kim, Taek-Soo,Lee, Jihoon,Lee, Jae Kyun,Park, Hyeung-geun American Chemical Society 2015 Journal of organic chemistry Vol.80 No.6
<P>An efficient enantioselective synthetic method for alpha-amido-alpha-alkylmalonates via phase-transfer catalytic alpha-alkylation was successfully developed. The alpha-alkylation of alpha-amidomalonates under phase-transfer catalytic conditions (50% KOH, toluene, -40 degrees C) in the presence of (S,S)-3,4,5-trifluorophenyl-NAS bromide afforded the corresponding alpha-amido-alpha-alkylmalonates in high chemical yields (up to 99%) and optical yields (up to 97% ee), which could be readily converted to versatile chiral intermediates bearing alpha-amino quaternary stereogenic centers. The synthetic potential of this methodology was demonstrated via the synthesis of chiral azlactone, oxazoline, and unnatural alpha-amino acid.</P>