Carbon–Carbon Bond Construction

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Organic Synthesis ◽  
Grignard Reagent ◽  
Secondary Amide ◽  
State University ◽  
Wayne State University ◽  
Carbon Carbon Bond ◽  
Diazo Ketone ◽  
Peking University ◽  
Subsequent Exposure ◽  
The University

Carlo Siciliano and Angelo Liguori of the Università della Calabria showed (J. Org. Chem. 2012, 77, 10575) that an amino acid 1 could be both protected and activated with Fmoc-Cl, so subsequent exposure to diazomethane delivered the Fmoc-protected diazo ketone 2. Pei-Qiang Huang of Xiamen University activated (Angew. Chem. Int. Ed. 2012, 51, 8314) a secondary amide 3 with triflic anhydride, then added an alkyl Grignard reagent with CeCl3 to give an intermediate that was reduced to the amine 4. John C. Walton of the University of St. Andrews found (J. Am. Chem. Soc. 2012, 134, 13580) that under irradiation, titania could effect the decarboxylation of an acid 5 to give the dimer 6. Jin Kun Cha of Wayne State University demonstrated (Angew. Chem. Int. Ed. 2012, 51, 9517) that a zinc homoenolate derived from 7 could be transmetalated, then coupled with an electrophile to give the alkylated product 8. The Ramberg-Bäcklund reaction is an underdeveloped method for the construction of alkenes. Adrian L. Schwan of the University of Guelph showed (J. Org. Chem. 2012, 77, 10978) that 10 is a particularly effective brominating agent for this transformation. Daniel J. Weix of the University of Rochester coupled (J. Org. Chem. 2012, 77, 9989) the bromide 12 with the allylic carbonate 13 to give 14. The Julia-Kocienski coupling, illustrated by the addition of the anion of 16 to the aldehyde 15, has become a workhorse of organic synthesis. In general, this reaction is E selective. Jirí Pospísil of the University Catholique de Louvain demonstrated (J. Org. Chem. 2012, 77, 6358) that inclusion of a K+-sequestering agent switched the selectivity to Z. Yoichiro Kuninobu, now at the University of Tokyo, and Kazuhiko Takai of Okayama University constructed (Org. Lett. 2012, 14, 6116) the tetrasubstituted alkene 20 with high geometric control by the Re-catalyzed addition of 19 to the alkyne 18. André B. Charette of the Université de Montréal converted (Org. Lett. 2012, 14, 5464) the allylic halide 21 to the alkyne 22 by displacement with iodoform followed by elimination. In an elegant extension of his studies with alkyl tosylhydrazones, Jianbo Wang of Peking University added (J. Am. Chem. Soc. 2012, 134, 5742) an alkyne 24 to 23 to give 25.

C–O Ring Formation

2015 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Kinetic Resolution ◽  
Lewis Base ◽  
State University ◽  
Wayne State University ◽  
Northwestern University ◽  
Iminium Ion ◽  
Peking University ◽  
Complete Reversal ◽  
Dyotropic Rearrangement ◽  
The University

A reductive radical cyclization of tetrahydropyran 1 to form bicycle 2 using iron(II) chloride in the presence of NaBH4 was reported (Angew. Chem. Int. Ed. 2012, 51, 6942) by Louis Fensterbank and Cyril Ollivier at the University of Paris and Anny Jutand at the Ecole Normale Supérieure. The enantioselective conversion of tetrahydrofuran 3 to spirocycle 5 via iminium ion-catalyzed hydride transfer/cyclization was developed (Angew. Chem. Int. Ed. 2012, 51, 8811) by Yong-Qiang Tu at Lanzhou University. Daniel Romo at Texas A&M University showed (J. Am. Chem. Soc. 2012, 134, 13348) that enantioenriched tricyclic β-lactone 8 could be readily prepared via dyotropic rearrangement of the diketoacid 6 under catalysis by chiral Lewis base 7. A dyotropic rearrangement was also utilized (Angew. Chem. Int. Ed. 2012, 51, 6984) by Zhen Yang at Peking University, Tuoping Luo at H3 Biomedicine in Cambridge, MA, and Yefeng Tang at Tsinghua University for the conversion of 9 to the bicyclic lactone 10. In terms of the enantioselective synthesis of β-lactones, Karl Scheidt at Northwestern University found that NHC catalyst 12 effects (Angew. Chem. Int. Ed. 2012, 51, 7309) the dynamic kinetic resolution of aldehyde 11 to furnish the lactone 13 with very high ee. Meanwhile, Xiaomeng Feng at Sichuan University has developed (J. Am Chem. Soc. 2012, 134, 17023) a rare example of an enantioselective Baeyer-Villiger oxidation of 4-alkyl cyclohexanones such as 14. The diastereoselective preparation of tetrahydropyran 18 by Lewis acid-promoted cyclization of cyclopropane 17 was accomplished (Org. Lett. 2012, 14, 6258) by Jin Kun Cha at Wayne State University. Stephen J. Connon at the University of Dublin reported (Chem. Commun. 2012, 48, 6502) the formal cycloaddition of aryl succinic anhydrides such as 18 with aldehydes to produce γ-butyrolactones, including 20, in high ee. The stereodivergent cyclization of 21 via desilylation-induced heteroconjugate addition to produce the complex tetrahydropyran 22 was discovered (Org. Lett. 2012, 14, 5550) by Paul A. Clarke at the University of York. Remarkably, while TFA produced a 13:1 diastereomeric ratio in favor of the cis diastereomer 22, the use of TBAF resulted in complete reversal of diastereoselectivity.

Carbon–Carbon Bond Formation: The Bergman Synthesis of (+)-Fuligocandin B

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Grignard Reagent ◽  
Alkyl Halide ◽  
Secondary Alcohol ◽  
Ni Catalyst ◽  
West Virginia University ◽  
Carbon Carbon Bond ◽  
Peking University ◽  
National University ◽  
The University ◽  
École Polytechnique

Xile Hu of the Ecole Polytechnique Fédérale de Lausanne optimized (J. Am. Chem. Soc. 2011, 133, 7084) a Ni catalyst for the coupling of a Grignard reagent 2 with a secondary alkyl halide 1. Duk Keun An of Kangwon National University devised (Tetrahedron Lett. 2011, 52, 1718; Chem. Commun. 2011, 47, 3281) a strategy for the reductive coupling of an ester 4 with a Grignard reagent 2 to give the secondary alcohol. Daniel J. Weix of the University of Rochester added (Org. Lett. 2011, 13, 2766) the halide 7 in a conjugate sense to the bromoenone 6, setting the stage for further organometallic coupling. James Y. Becker of the Ben-Gurion University of the Negev effected (J. Org. Chem. 2011, 76, 4710) Kolbe coupling of the silyl acid 9 to give the decarboxylated dimer 10. Shi-Kai Tian of USTC Hefei showed (Chem. Commun. 2011, 47, 2158) that depending on the sulfonyl group used, the coupling of 11 with 12 could be directed cleanly toward either the Z or the E product. Yoichiro Kuninobu and Kazuhiko Takai of Okayama University added (Org. Lett. 2011, 13, 2959) the sulfonyl ketone 14 to the alkyne 13 to form the trisubstituted alkene 15. Jianbo Wang of Peking University assembled (Angew. Chem. Int. Ed. 2011, 50, 3510) the trisubstituted alkene 18 by adding the diazo ester 16 to the alkyne 17. Gangguo Zhu of Zhejiang Normal University constructed (J. Org. Chem. 2011, 76, 4071) the versatile tetrasubstituted alkene 21 by adding the chloroalkyne 19 to acrolein 20. Other more substituted acceptors worked as well. Chunxiang Kuang of Tongji University and Qing Yang of Fudan University effected (Tetrahedron Lett. 2011, 52, 992) elimination of 22 to 23 by stirring with Cs2CO3 at 115°C in DMSO overnight. Toshiaki Murai of Gifu University created (Chem. Lett. 2011, 40, 70) a propargyl anion by condensing 24 with 25 then adding 26. Xiaodong Shi of West Virginia University found (Org. Lett. 2011, 13, 2618) that the enantiomerically enriched propargyl ether 29 could be rearranged to the trisubsituted allene 30 with retention of the ee and with high de.

Carbon–Carbon Bond Construction: The Baran Synthesis of (+)-Chromazonarol

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Grignard Reagent ◽  
Iron Catalyst ◽  
Alkyl Halide ◽  
Titanocene Dichloride ◽  
Secondary Amide ◽  
Reductive Coupling ◽  
Quaternary Centers ◽  
Carbon Carbon Bond ◽  
The University

Daniel J. Weix of the University of Rochester effected (Org. Lett. 2012, 14, 1476) the in situ reductive coupling of an alkyl halide 2 with an acid chloride 1 to deliver the ketone 3. André B. Charette of the Université de Montréal (not illustrated) developed (Nature Chem. 2012, 4, 228) an alternative route to ketones by the coupling of an organometallic with an in situ-activated secondary amide. Mahbub Alam and Christopher Wise of the Merck, Sharpe and Dohme UK chemical process group optimized (Org. Process Res. Dev. 2012, 16, 453) the opening of an epoxide 4 with a Grignard reagent 5. Ling Song of the Fujian Institute of Research on the Structure of Matter optimized (J. Org. Chem. 2012, 77, 4645) conditions for the 1,2-addition of a Grignard reagent (not illustrated) to a readily enolizable ketone. Wei-Wei Liao of Jilin University conceived (Org. Lett. 2012, 14, 2354) of an elegant assembly of highly functionalized quaternary centers, as illustrated by the conversion of 7 to 8. Antonio Rosales of the University of Granada and Ignacio Rodríguez-García of the University of Almería prepared (J. Org. Chem. 2012, 77, 4171) free radicals by reduction of an ozonide 9 in the presence of catalytic titanocene dichloride. In the absence of the acceptor 10, the dimer of the radical was obtained, presenting a simple alternative to the classic Kolbe coupling. Marc L. Snapper of Boston College found (Eur. J. Org. Chem. 2012, 2308) that the difficult ketone 12 could be methylenated following a modified Peterson protocol. Yoshito Kishi of Harvard University optimized (Org. Lett. 2012, 14, 86) the coupling of 15 with 16 to give 17. Masaharu Nakamura of Kyoto University devised (J. Org. Chem. 2012, 77, 1168) an iron catalyst for the coupling of 18 with 19. The specific preparation of trisubsituted alkenes is an ongoing challenge. Quanri Wang of Fudan University and Andreas Goeke of Givaudan Shanghai fragmented (Angew. Chem. Int. Ed. 2012, 51, 5647) the ketone 21 by exposure to 22 to give the macrolide 23 with high stereocontrol.

Substituted Benzenes: The Saikawa/Nakata Synthesis of Kendomycin

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Alkyl Iodide ◽  
Benzene Derivative ◽  
State University ◽  
One Pot ◽  
Aryl Iodide ◽  
Peking University ◽  
Cu Catalyst ◽  
San Diego State University ◽  
University Of Massachusetts ◽  
The University

Jianbo Wang of Peking University described (Angew. Chem. Int. Ed. 2010, 49, 2028) the Au-promoted bromination of a benzene derivative such as 1 with N-bromosuccinimide. In a one-pot procedure, addition of a Cu catalyst followed by microwave heating delivered the aminated product 2. Jian-Ping Zou of Suzhou University and Wei Zhang of the University of Massachusetts, Boston, observed (Tetrahedron Lett. 2010, 51, 2639) that the phosphonylation of an arene 3 proceeded with substantial ortho selectivity. Yonghong Gu of the University of Science and Technology, Hefei, showed (Tetrahedron Lett. 2010, 51, 192) that an arylpropanoic acid 6 could be ortho hydroxylated with PIFA to give 7. Louis Fensterbank, Max Malacria, and Emmanuel Lacôte of UMPC Paris found (Angew. Chem. Int. Ed. 2010, 49, 2178) that a benzoic acid could be ortho aminated by way of the cyano amide 8. Daniel J. Weix of the University of Rochester developed (J. Am. Chem. Soc. 2010, 132, 920) a protocol for coupling an aryl iodide 10 with an alkyl iodide 11 to give 12. Professor Wang devised (Angew. Chem. Int. Ed. 2010, 49, 1139) a mechanistically intriguing alkyl carbonylation of an iodobenzene 10. This is presumably proceeding by way of the intermediate diazo alkane. Usually, benzonitriles are prepared by cyanation of the halo aromatic. Hideo Togo of Chiba University established (Synlett 2010, 1067) a protocol for the direct electrophilic cyanation of an electron-rich aromatic 15. Thomas E. Cole of San Diego State University observed (Tetrahedron Lett. 2010, 51, 3033) that an alkyl dimethyl borane, readily prepared by hydroboration of the alkene with BCl3 and Et3 SiH, reacted with benzoquinone 17 to give 18. Presumably this transformation could also be applied to substituted benzoquinones. When a highly substituted benzene derivative is needed, it is sometimes more economical to construct the aromatic ring. Joseph P. A. Harrity of the University of Sheffield and Gerhard Hilt of Philipps-Universität Marburg showed (J. Org. Chem. 2010, 75, 3893) that the Co-catalyzed Diels-Alder cyloaddition of alkynyl borinate 21 with a diene 20 proceeded with high regiocontrol, to give, after oxidation, the aryl borinate 22.

Alkaloid Synthesis: Indolizidine 223AB (Cha), Lepadiformine (Kim), Kainic Acid (Fukuyama), Gephyrotoxin (Smith), Premarineosin A (Reynolds)

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Kainic Acid ◽  
Claisen Rearrangement ◽  
State University ◽  
University Of Oxford ◽  
Wayne State University ◽  
Peking University ◽  
Portland State University ◽  
National University ◽  
Ester Enolate ◽  
Indolizidine 223Ab

Jin Kun Cha of Wayne State University prepared (Org. Lett. 2014, 16, 6208) the allene 1 by SN2′ coupling of a cyclopropanol with a propargylic tosylate. Silver-mediated cyclization converted 1 into 2, that was reduced with diimide to the Dendrobates alka­loid indolizidine 223AB 3. Sanghee Kim of Seoul National University observed (Chem. Eur. J. 2014, 20, 17433) high diastereoselectivity in the Ireland–Claisen rearrangement of 4 to 5. The acid 5 was the key intermediate for the synthesis of the tunicate alkaloid lepadiformine 6. Tohru Fukuyama of Nagoya University also used (Eur. J. Org. Chem. 2014, 4823) an ester enolate Claisen rearrangement to set the relative and absolute configuration of 7. Pd-catalyzed cyclization then led to 8, that was carried on to the excitatory amino acid receptor agonist kainic acid 9. Gephyrotoxin 12 was so named because it incorporates structural elements from two different classes of the Dendrobates alkaloids. Martin D. Smith of the University of Oxford envisioned (Angew. Chem. Int. Ed. 2014, 53, 13826) the cascade cyclization of deprotected 10 to give, after reduction, the ketone 11. Zhen Yang of the Peking University Shenzhen Graduate School showed (Chem. Eur. J. 2014, 20, 12881) that the Rh carbene derived from 13 readily cyclized to an imine. The facial selectivity of the addition of the Grignard reagent 14 to that imine depended on the temperature of the reaction. At room temperature, 15 was formed. At low temperature, the other diastereomer predominated. Ring-closing metathesis was used for the elaboration of 15 to the Stemona alkaloid tuberostemospiroline 16. Kevin A. Reynolds of Portland State University prepared (J. Org. Chem. 2014, 79, 11674) 19 by condensation of the pyrrole 17 with the aldehyde 18. The biosyn­thetic enzyme, that they had overexpressed, oxidized 19 to the antimalarial alkaloid permarineosin A 20.

Flow Chemistry: The Direct Production of Drug Metabolites

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Organic Synthesis ◽  
Flow Chemistry ◽  
Florida State University ◽  
State University ◽  
Max Planck ◽  
Direct Production ◽  
Reactor Technology ◽  
University Of Cambridge ◽  
The University

Several overviews of flow chemistry appeared recently. Katherine S. Elvira and Andrew J. deMello of ETH Zürich wrote (Nature Chem. 2013, 5, 905) on micro­fluidic reactor technology. D. Tyler McQuade of Florida State University and the Max Planck Institute Mühlenberg reviewed (J. Org. Chem. 2013, 78, 6384) applications and equipment. Jun-ichi Yoshida of Kyoto University focused (Chem. Commun. 2013, 49, 9896) on transformations that cannot be effected under batch condi­tions. Detlev Belder of the Universität Leipzig reported (Chem. Commun. 2013, 49, 11644) flow reactions coupled to subsequent micropreparative separations. Leroy Cronin of the University of Glasgow described (Chem. Sci. 2013, 4, 3099) combin­ing 3D printing of an apparatus and liquid handling for convenient chemical synthe­sis and purification. Many of the reactions of organic synthesis have now been adapted to flow con­ditions. We will highlight those transformations that incorporate particularly useful features. One of those is convenient handling of gaseous reagents. C. Oliver Kappe of the Karl-Franzens-University Graz generated (Angew. Chem. Int. Ed. 2013, 52, 10241) diimide in situ to reduce 1 to 2. David J. Cole-Hamilton immobilized (Angew. Chem. Int. Ed. 2013, 52, 9805) Ru DuPHOS on a heteropoly acid support, allowing the flow hydrogenation of neat 3 to 4 in high ee. Steven V. Ley of the University of Cambridge added (Org. Process Res. Dev. 2013, 17, 1183) ammonia to 5 to give the thiourea 6. Alain Favre-Réguillon of the Conservatoire National des Arts et Métiers used (Org. Lett. 2013, 15, 5978) oxygen to directly oxidize the aldehyde 7 to the car­boxylic acid 8. Professor Kappe showed (J. Org. Chem. 2013, 78, 10567) that supercritical ace­tonitrile directly converted an acid 9 to the nitrile 10. Hisao Yoshida of Nagoya University added (Chem. Commun. 2013, 49, 3793) acetonitrile to nitrobenzene 11 to give the para isomer 12 with high regioselectively. Kristin E. Price of Pfizer Groton coupled (Org. Lett. 2013, 15, 4342) 13 to 14 to give 15 with very low loading of the Pd catalyst. Andrew Livingston of Imperial College demonstrated (Org. Process Res. Dev. 2013, 17, 967) the utility of nanofiltration under flow conditions to minimize Pd levels in a Heck product.

Eliyana R. Adler and Sheila E. Jelen (eds.), Reconstructing the Old Country: American Jewry in the Post-Holocaust Decades. Detroit: Wayne State University Press, 2017. xviii + 374 pp.

2020 ◽  
pp. 249-251
Keyword(s):  
The United States ◽  
State University ◽  
American Jews ◽  
University Of Maryland ◽  
Wayne State University ◽  
American Jewry ◽  
The Holocaust ◽  
The First World War ◽  
The University ◽  
First World

This anthology stems from a 2014 conference at the University of Maryland, which focused on how American Jews provided material aid to Holocaust refugees during and after the Holocaust, and also how they began to cope with the catastrophe. This coping involved both an imagining and a re-imagining of “the old country,” a reevaluation of the places American Jews had left behind in more or less normal circumstances before the First World War but in increasingly desperate circumstances after 1918 and, again, after 1939. American Jews who had come to the United States before the 1920s maintained ties with their former communities in Central and Eastern Europe, ties that were fostered by efforts to remain in touch with family and friends and, more generally, with the world’s most populous Jewish communities. Those efforts were aided by the ...

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