- Highly Enantioselective Iridium-Catalyzed Hydrogenation of Conjugated Trisubstituted Enones
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Asymmetric hydrogenation of conjugated enones is one of the most efficient and straightforward methods to prepare optically active ketones. In this study, chiral bidentate Ir-N,P complexes were utilized to access these scaffolds for ketones bearing the stereogenic center at both the α- and β-positions. Excellent enantiomeric excesses, of up to 99%, were obtained, accompanied with good to high isolated yields. Challenging dialkyl substituted substrates, which are difficult to hydrogenate with satisfactory chiral induction, were hydrogenated in a highly enantioselective fashion.
- Peters, Bram B. C.,Jongcharoenkamol, Jira,Krajangsri, Suppachai,Andersson, Pher G.
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supporting information
p. 242 - 246
(2021/01/13)
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- Design, synthesis and antitumor activity evaluation of Chrysamide B derivatives
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Marine natural products derived from special or extreme environment provide an important source for the development of anti-tumor drugs due to their special skeletons and functional groups. In this study, based on our previous work on the total synthesis and structure revision of the novel marine natural product Chrysamide B, a group of its derivatives were designed, synthesized, and subsequently of which the anti-cancer activity, structure-activity relationships and cellular mechanism were explored for the first time. Compared with Chrysamide B, better anti-cancer performance of some derivatives against five human cancer cell lines (SGC-7901, MGC-803, HepG2, HCT-116, MCF-7) was observed, especially for compound b-9 on MGC-803 and SGC-7901 cells with the IC 50 values of 7.88 ± 0.81 and 10.08 ± 1.08 μM, respectively. Subsequently, cellular mechanism study suggested that compound b-9 treatment could inhibit the cellular proliferation, reduce the migration and invasion ability of cells, and induce mitochondrial-dependent apoptosis in gastric cancer MGC-803 and SGC-7901 cells. Furthermore, the mitochondrial-dependent apoptosis induced by compound b-9 is related with the JAK2/STAT3/Bcl-2 signaling pathway. To conclude, our results offer a new structure for the discovery of anti-tumor lead compounds from marine natural products.
- Zhu, Longqing,Li, Junfang,Fan, Xiaohong,Hu, Xiaoling,Chen, Jinhong,Liu, Yonghong,Hao, Xiangyong,Shi, Tao,Wang, Zhen,Zhao, Quanyi
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- Total synthesis of chrysamide B
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We report an efficient synthesis of the dimeric trans-epoxyamide chrysamide B, recently isolated from the deep-sea-derived fungus Penicillium chrysogenum SCSIO41001. Our synthetic strategy exploits a convergent approach using solid-phase peptide synthesis for the piperazine core and a Sharpless-Katsuki epoxidation to prepare the chiral epoxyacid. The double amidation final step provides chrysamide B that was thoroughly characterized with all spectra identical to those of the natural sample. The approach was devised to facilitate the preparation of a library of analogs of chrysamide B.
- Bérubé, Christopher,Carpentier, Claudia,Voyer, Normand
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supporting information
p. 2334 - 2336
(2017/05/29)
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- Multifactorial control of iteration events in a modular polyketide assembly line
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Freedom and control: First insights into the rare programmed iteration of an individual polyketide synthase (PKS) module were obtained from the analysis and mutation of aureothin (1) synthase. The first ketosynthase (KS) domain primes the PKS, allowing intermediate retrotransfer. Addition of a designated loading module results in a complete loss of iteration. The downstream KS functions as a gatekeeper for correct chain length. Copyright
- Busch, Benjamin,Ueberschaar, Nico,Behnken, Swantje,Sugimoto, Yuki,Werneburg, Martina,Traitcheva, Nelly,He, Jing,Hertweck, Christian
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supporting information
p. 5285 - 5289
(2013/06/26)
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- Rasta Resin-PPh3-NBniPr2 and its use in one-pot wittig reaction cascades
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A new triarylphosphine-tertiary amine bifunctional polymeric reagent has been prepared and used effectively in a variety of one-pot Wittig reactions. The design of this reagent resolved a deficiency of a previously reported related material, and allowed it to perform more efficiently in such reactions. Furthermore, it was readily recyclable, and was also successfully applied in cascade processes involving one-pot Wittig reactions followed by either a conjugate reduction or a reductive aldol reaction. In these reaction cascades, the phosphine oxide groups generated in the Wittig reaction served as the catalyst for the subsequent reaction. All in one pot! A recyclable, second-generation heterogeneous bifunctional polymer bearing phosphine and amine groups has been synthesized and showed enhanced utility in one-pot Wittig reactions compared to a previously reported related material. This polymer was also used in Wittig reaction cascade processes in which the oxidized polymer formed in the one-pot Wittig reaction served as the catalyst in a subsequent conjugate reduction or reductive aldol reaction (see scheme).
- Teng, Yan,Lu, Jinni,Toy, Patrick H.
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experimental part
p. 351 - 359
(2012/04/18)
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- Interchenar retrotransfer of aureothin intermediates in an iterative polyketide synthase module
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The course of the enigmatic iterative use of a polyketide synthase module was deduced from targeted domain inactivation in the aureothin assembly line. Mutational analyses revealed that the N-terminus of AurA is not involved in the iteration process, ruli
- Busch, Benjamin,Ueberschaar, Nico,Sugimoto, Yuki,Hertweck, Christian
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supporting information; scheme or table
p. 12382 - 12385
(2012/08/29)
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- An efficient and general method for the heck and buchwald-hartwig coupling reactions of aryl chlorides
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The β-diketiminatophosphane Pd complex acted as a powerful catalyst for the Heck coupling of aryl chlorides with alkenes. Various aryl and heteroaryl chlorides were coupled efficiently under relatively mild conditions. Furthermore, this catalytic system also proved to be highly active in the Buchwald-Hartwig coupling of deactivated and sterically hindered aryl chlorides at room temperature.
- Lee, Dong-Hwan,Taher, Abu,Hossain, Shahin,Jin, Myung-Jong
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supporting information; experimental part
p. 5540 - 5543
(2011/12/15)
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- A convenient synthesis of (E)-α,β-unsaturated esters with total stereoselectivity promoted by catalytic samarium diiodide
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Synthesis of (E)-α,β-unsaturated esters in high yields and with total stereoselectivity is achieved from α-halo-β-hydroxy esters promoted by catalytic amounts of SmI2. The starting compounds were easily prepared from α-halo esters and aldehydes as a mixture of stereoisomers. A mechanism is proposed to explain this samarium(II)-promoted catalytic β-elimination reaction. Georg Thieme Verlag Stuttgart.
- Concellón, José M.,Rodríguez-Solla, Humberto,Concellón, Carmen,Díaz-Pardo, Ainhoa,Llavona, Ricardo
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experimental part
p. 262 - 264
(2011/03/21)
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- GPR120 RECEPTOR AGONISTS AND USES THEREOF
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GPR120 agonists are provided. These compounds are useful for the treatment of metabolic diseases, including Type II diabetes and diseases associated with poor glycemic control.
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Page/Page column 122
(2012/01/06)
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- GPR120 RECEPTOR AGONISTS AND USES THEREOF
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GPR120 agonists are provided. These compounds are useful for the treatment of metabolic diseases, including Type II diabetes and diseases associated with poor glycemic control.
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Page/Page column 49-50
(2012/01/13)
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- Chromatography-free wittig reactions using a bifunctional polymeric reagent
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The first example of a polystyrene bearing two distinct reagent groups has been prepared. This phosphine and amine functionalized material was used in one-pot Wittig reactions with an aldehyde and either an α-halo-ester, -ketone, or -amide. Due to the heterogeneous nature of the polymer, the desired alkene product of these reactions could be isolated in excellent yield in essentially pure form after only filtration and solvent removal.
- Leung, Peter Shu-Wai,Teng, Yan,Toy, Patrick H.
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supporting information; experimental part
p. 4996 - 4999
(2010/12/25)
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- Rasta resin-PPh3 and its use in chromatography-free wittig reactions
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Rasta resin-PPh3, a new heterogeneous polystyrene-based phosphine, has been synthesized and used in one-pot Wittig olefination reactions of aldehydes. In these reactions an excess of rasta resin-PPh3 was used for the in situ generation of the phosphorane reactant and allowed for isolation of a high yield of very pure alkene product after only filtration and solvent removal. The excellent results obtained in this study are attributed to the flexible nature of the rasta resin structure, which makes it less dependant upon swelling than other heterogeneous polystyrene materials previously used to support phosphine reagents in Wittig reactions. Georg Thieme Verlag Stuttgart.
- Leung, Peter Shu-Wai,Teng, Yan,Toy, Patrick H.
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supporting information; experimental part
p. 1997 - 2001
(2010/10/02)
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- BIS(TRIMETHYLSILYL)PHENYL COMPOUND OR SALT THEREOF, AND USE THEREOF
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The present invention provides a compound that exhibits an excellent antitumor effect and reduces side effects, such as skin disorders, of the existing retinoid by selectively activating on the nuclear receptor RARα, thereby possibly producing significant
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Page/Page column 25
(2010/07/08)
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- GPR120 RECEPTOR AGONISTS AND USES THEREOF
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GPR120 agonists are provided. These compounds are useful for the treatment of metabolic diseases, including Type II diabetes and diseases associated with poor glycemic control.
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Page/Page column 96
(2010/08/04)
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- Synthesis of trisubstituted alkenes by reductive dehydroxylation of Baylis-Hillman adducts using polymethylhydrosiloxane (PMHS) and catalytic B(C6F5)3
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B(C6F5)3 as a catalyst and polymethylhydrosiloxane as a hydride source have been employed for the reductive dehydroxylation of Baylis-Hillman adducts wherein the hydride adds in an SN2′ manner onto the unactivat
- Chandrasekhar,Chandrashekar,Vijeender,Reddy, M. Srinivasa
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p. 3475 - 3478
(2007/10/03)
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- Synthesis and characterization of pentaerythritol-derived oligoglycol and their application to catalytic Wittig-type reactions
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Several pentaerythritol-derived oligoglycols 1 with free hydroxyl groups are readily prepared by a convergent approach. Quantitative 13C NMR proves to be an efficient tool for the characterization of oligoglycols. The corresponding telluride of oligoglycol 17 is synthesized and used as a good catalyst for Wittig-type reactions in preparing both disubstituted and trisubstituted olefins in good to high yields.
- Li, Kai,Ran, Li,Yu, Yi-Hua,Tang, Yong
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p. 3986 - 3989
(2007/10/03)
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- Biomimetic studies on polyenes.
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The crispatenes and SNF4435 C&D are complex polypropionate derived natural products. The core structures of these compounds along with a complex unnatural structure can be easily prepared from a common polyene precursor simply by variation of the reaction conditions. The reaction pathways provide insight into the biosynthesis of these complex natural products.
- Moses, John E,Baldwin, Jack E,Brueckner, Sebastien,Eade, Serena J,Adlington, Robert M
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p. 3670 - 3684
(2007/10/03)
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- Studies on the biomimetic synthesis of SNF4435 C and D
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(equation Presented) The biomimetic synthesis of the bicyclic core of the novel immunosuppresants SNF4435C and SNF4435D is reported. The core framework was efficiently generated from the all-trans tetraene precursor in one step and in good yield.
- Moses, John E.,Baldwin, Jack E.,Marquez, Rodolfo,Adlington, Robert M.,Cowley, Andrew R.
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p. 3731 - 3734
(2007/10/03)
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- Kinetic study of microwave-assisted Wittig reaction of stabilised ylides with aromatic aldehydes
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The Wittig reaction of a pool of stabilised ylides and aromatic aldehydes was carried out in a microwave oven. Only a few minutes were needed for high conversion rates under microwave heating in comparison to hour time with traditional methods.
- Frattini, Sara,Quai, Monica,Cereda, Enzo
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p. 6827 - 6829
(2007/10/03)
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- Activated Alumina Promoted Stereoselective Wittig Reaction
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Aldehydes undergo efficient E-stereoselective Wittig olefination with alkylidenetriphenylphosphoranes in the presence of activated alumina under mild conditions with high yields.
- Dhavale, Dilip D.,Sindkhedkar, Milind D.,Mali, Raghao S.
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p. 414 - 415
(2007/10/03)
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- Phenylcarboxylic acid derivatives
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Phenylcarboxylic acid derivatives having the formula: STR1 wherein R1 and R2 are each H, halogen, alkyl, haloalkyl, alkanoyl, cycloalkyl, nitro, amino, --O--D--R5 (D is alkylene, R5 is H, amino, morpholino, carboxyl, phthalimido, phenyl, epoxy), substituted or unsubstituted phenoxy, substituted or unsubstituted phenylalkylamino, carboxylalkenyl, or both form alkylenedioxy; R3 is H, --E--R6 (E is alkylene, R6 is H, carboxyl, cyano, OH, phenylalkoxy, or halogen-substituted phenyl, or phenylcarbamoyl), --CO--G--R7 (G is alkylene, R7 is H, substituted or unsubstituted phenylcarbamoyl), substituted or unsubstituted benzoyl, alkenyl, carbamoyl, phenyl, or halophenyl; R4 is H or alkyl; A is alkylene, alkylene condensed with cycloalkyl ring, or alkenylene; B is alkylene or alkenylene; l is 0 or 1. Said compounds have fatty acid synthesis-inhibitory activity, cholesterol synthesis-inhibitory activity and are useful as antilipidemic agent, prophylactic and treating agent of artherosclerosis, prophylactic and treating agent of obesity, antidiabetics.
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- Process for the Pd-catalyzed arylation of olefins with aryl halides
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Compounds of the formula I STR1 in which A is C2-12 -alkenyl, C4-8 -cycloalkenyl or a grouping--C(R)=C(R')--Y and Y, R, R', R1, R2, R3 and R3 ' are as defined in patent claim 1, can be prepared in high yields in a simple and economical manner by reacting corresponding bromobenzenes or iodobenzenes with a compound HA in the presence of an alkali metal salt or alkaline earth metal salt of an aliphatic monocarboxylic acid having 1-12 C atoms or benzoic acid, of a cyclic or N,N-disubstituted amide as the solvent, particularly N,N-dimethylformamide, and of a palladium compound which can, if desired, contain arsenic or phosphorus, as the catalyst.
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- Carboxamide compounds as SRS-A antagonists
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The compounds of the invention are certain new propenamides and 2-butenamides having a (carboxyalkanamido)phenyl or a (carboxyalkenamido)phenyl group at the 3-position, and certain esters thereof, and certain cyclopropanecarboxamide compounds having a (ca
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- Carboxamide compounds as SRS-A antagonists
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The compounds of the invention are certain new propenamide and 2-butenamide compounds, having a (4-carboxy-2-oxo-pyrrolidino)phenyl substituent at the 3-position, and certain esters thereof, and certain cyclopropanecarboxamide compounds, having a (4-carbo
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- (Carboxy-oxo-pyrrolidino)phenylalkenamides and esters thereof as SRS-A antagonists
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Certain new propenamide and 2-butenamide compounds, having a (4-carboxy-2-oxo-pyrrolidino)phenyl substituent at the 3-position, and certain esters thereof, and their use for antagonizing the spasmogenic activity of slow-reacting substance of anaphylaxis (
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- (Carboxyacylamino)phenylalkenamides and esters thereof as SRS-A antagonists
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Certain new propenamides and 2-butenamides having a (carboxyalkanamido)phenyl or a (carboxyalkenamido)phenyl group at the 3-position, and certain esters thereof, and their use for antagonizing the spasmogenic activity of slow-reacting substance of anaphyl
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