C–H Functionalization: The Maimone Synthesis of Podophyllotoxin

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
University Of California ◽  
University Of Illinois ◽  
Methyl Group ◽  
Du Bois ◽  
Princeton University ◽  
University Of Cambridge ◽  
Rh Catalyst ◽  
Institute Of Technology ◽  
La Jolla ◽  
The University

Matthias Beller of the Universität Rostock developed (Angew. Chem. Int. Ed. 2014, 53, 6477) a Rh catalyst for the acceptorless dehydrogenation of an alkane 1 to the alkene 2. Bhisma K. Patel of the Indian Institute of Technology Guwahati effected (Org. Lett. 2014, 16, 3086) oxidation of cyclohexane 3 and 4 to form the allylic benzoate 5. Justin Du Bois of Stanford University devised (Chem. Sci. 2014, 5, 656) an organocatalyst that mediated the hydroxylation of 6 to 7. Vladimir Gevorgyan of the University of Illinois, Chicago hydrosilylated (Nature Chem. 2014, 6, 122) 8 to give an intermediate that, after Ir-catalyzed intramolecular C–H functionalization followed by oxidation, was converted to the diacetate 9. Sukbok Chang of KAIST used (J. Am. Chem. Soc. 2014, 136, 4141) the methoxime of 10 to direct selective amination of the adjacent methyl group, leading to 11. John F. Hartwig of the University of California, Berkeley effected (J. Am. Chem. Soc. 2014, 136, 2555) diastereoselective Cu-catalyzed amination of 12 with 13 to make 14. David W. C. MacMillan of Princeton University accomplished (J. Am. Chem. Soc. 2014, 136, 6858) β-alkylation of the aldehyde 15 with acrylonitrile 16 to give 17. Yunyang Wei of the Nanjing University of Science and Technology alkenylated (Chem. Sci. 2014, 5, 2379) cyclohexane 3 with the styrene 18, leading to 19. Bin Wu of the Kunming Institute of Botany described (Org. Lett. 2014, 16, 480) the Pd-mediated cyclization of 20 to 21. Similar results using Cu catalysis were reported (Angew. Chem. Int. Ed. 2014, 53, 3496, 3706) by Yoichiro Kuninobu and Motomu Kanai of the University of Tokyo and by Haibo Ge of IUPUI. Jin-Quan Yu of Scripps La Jolla constructed (J. Am. Chem. Soc. 2014, 136, 5267) the lactam 24 by γ-alkenyl­ation of the amide 22 with 23, followed by cyclization. Philippe Dauban of CNRS Gif-sur-Yvette prepared (Eur. J. Org. Chem. 2014, 66) the useful crystalline chiron 27 by asymmetric amination of the enol triflate 26 with 25. Matthew J. Gaunt of the University of Cambridge showed (J. Am. Chem. Soc. 2014, 136, 8851) that the phenylative cyclization of 28 with 29 to 30 proceeded with near-perfect retention of absolute configuration.

C–H Functionalization: The Hatakeyama Synthesis of (–)-Kaitocephalin

2015 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
University Of California ◽  
University Of Delaware ◽  
State University ◽  
Max Planck ◽  
Pennsylvania State University ◽  
University Of Illinois ◽  
University Of Houston ◽  
Hydride Abstraction ◽  
La Jolla ◽  
The University

John F. Hartwig of the University of California, Berkeley showed (Nature 2012, 483, 70) that intramolecular C–H silylation of 1 selectively gave, after oxidation and acetylation, the bis acetate 2. Gong Chen of Pennsylvania State University coupled (J. Am. Chem. Soc. 2012, 134, 7313) 3 with 4 to give the ether 5. M. Christina White of the University of Illinois effected (J. Am. Chem. Soc. 2012, 134, 9721) selective oxidation of the taxane derivative 6 to the lactone 7. Most of the work on C–H functionalization has focused on the formation of C–C, C–O, and C–N bonds. Donald A. Watson of the University of Delaware developed (Angew. Chem. Int. Ed. 2012, 51, 3663) conditions for the complementary conversion of an alkene 8 to the allyl silane 9, a powerful and versatile nucleophile. Kilian Muniz of ICIQ Tarragona oxidized (J. Am. Chem. Soc. 2012, 134, 7242) the enyne 10 selectively to the amine 11. Phil S. Baran of Scripps/La Jolla devised (J. Am. Chem. Soc. 2012, 134, 2547) a protocol for the OH-directed amination of 12 to 13. Professor White developed (J. Am. Chem. Soc. 2012, 134, 2036) a related OH-directed amination of 14 to 15 that proceeded with retention of absolute configuration. Tom G. Driver of the University of Illinois, Chicago showed (J. Am. Chem. Soc. 2012, 134, 7262) that the aryl azide 16 could be cyclized directly to the amine, which was protected to give 17. As illustrated by the conversion of 18 to 20 devised (Adv. Synth. Catal. 2012, 354, 701) by Martin Klussmann of the Max-Planck-Institut, Mülheim, C–H functionalization can be accomplished by hydride abstraction followed by coupling of the resulting carbocation with a nucleophile. Olafs Daugulis of the University of Houston used (Angew. Chem. Int. Ed. 2012, 51, 5188) a Pd catalyst to couple 21 with 22 to give 23 with high diastereocontrol. Yoshiji Takemoto of Kyoto University cyclized (Angew. Chem. Int. Ed. 2012, 51, 2763) the chloroformate 24 directly to the oxindole 25.

C-N Ring Construction: The Synthesis of Decursivine by Mascal and by Jia

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Pyridinium Salt ◽  
University Of California ◽  
Reductive Coupling ◽  
University Of Arkansas ◽  
Santa Barbara ◽  
University Of Illinois ◽  
Enantiomerically Pure ◽  
Du Bois ◽  
Duke University ◽  
The University

Barry M. Trost and Justin Du Bois of Stanford University described (Org. Lett. 2011, 13, 3336) the cyclization of 1 to the activated aziridine 2. Liming Zhang of the University of California, Santa Barbara, rearranged (Angew. Chem. Int. Ed. 2011, 50, 3236) the propergylic amine 3 to the azetidinone 4 by N-H insertion of an intermediate Au carbene. Xiao Zheng and Pei-Qiang Huang of Xiamen University effected (J. Org. Chem. 2011, 76, 4952) reductive coupling of 6 with 7 to deliver the ester 8 . Eiji Tayama of Niigata University found (Tetrahedron Lett. 2011, 52, 1819) that 9 could be alkenylated with 10 with substantial retention of absolute configuration. Duncan J. Wardrop of the University of Illinois at Chicago, en route to a synthesis of (-)-swainsonine, observed (Org. Lett. 2011 , 13, 2376) high diastereocontrol in the cyclization of 12 to 13. Iain Coldham of the University of Sheffield also observed (J. Org. Chem. 2011, 76, 2360) substantial diastereoselection in the cyclization of 14 to 15. Robert E. Gawley of the University of Arkansas established (Org. Lett. 2011, 13, 394) that exposure of metalated 16 to just 5 mol % of a chiral ligand was sufficient to enable enantioselective coupling, to deliver 17. Christian Nadeau of Merck Frosst effected (J. Am. Chem. Soc. 2011, 133, 2878) enantioselective addition to the pyridinium salt 19 to give 20. Jiyong Hong of Duke University observed (Org. Lett. 2011, 13, 796) that enantiomerically pure 21 cyclized to the cis diastereomer of 22. With the Hayashi catalyst, cyclization could be driven toward the trans diastereomer, 22, enabling the synthesis of (+)-myrtine. Dawei Ma of the Shanghai Institute of Organic Chemistry found (Org. Lett. 2011, 13, 1602) that the Hayashi catalyst also directed the relative and absolute outcome in the addition of 24 to 23 , to give the piperidine 25. Donn G. Wishka of Pfizer/Groton devised (J. Org. Chem. 2011, 76, 1937) a practical route to the cis-substituted azepane 27, by Beckmann rearrangement of the enantiomerically pure 26 followed by reduction and oxidative cleavage.

Protection of Organic Functional Groups

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
University Of California ◽  
Pd Catalyst ◽  
Protecting Group ◽  
New Developments ◽  
Rutgers University ◽  
Organic Functional Groups ◽  
Rh Catalyst ◽  
Institute Of Technology ◽  
The University ◽  
Mild Acid

Several noteworthy new developments in the protection and deprotection of alcohols have been reported. Andrea Biffis of the Università di Padova has developed (Adv. Synth. Catal. 2007, 349, 2485) a Rh catalyst that effected silylation of alcohols such as 1 to the TES ether 2 at just 0.01% loading. Joshua Rokach of the Florida Institute of Technology has observed (Tetrahedron Lett. 2007, 48, 5289) that the reverse reaction, Rh-catalyzed desilylation of 3, was highly selective for the less congested site, even removing the usually less reactive TBS ether of 3 and leaving the more hindered TES ether. Hirokazu Tsukamoto of Tohoku University has devised (Tetrahedron Lett. 2007, 48, 8438) an improved procedure for the deprotection of allyl ethers such as 5. Filtration of the reaction mixture through polymer- bound diethanolamine removed > 95% of the Pd from the product. Patrick Pale of the Université Louis Pasteur has established (Tetrahedron Lett. 2007, 48, 8895) improved con- ditions for preparing diphenylmethyl ethers such as 10. The protecting group was removed with the Pd catalyst and ethanol. Amines can be activated for alkylation by N-formylation. Subsequent deformylation of the alkylated formamide 11 has been a challenge. Longqin Hu of Rutgers University has developed (Tetrahedron Lett . 2007, 48, 4585) microwave conditions that work well. Carbamates are stable, but esters are not. Protection of amides can also be important. Michael J. Zacuto of Merck Process in Rahway, NJ has optimized (J. Org. Chem. 2007, 72, 6298) the Rh-catalyzed deallylation of 13 to give 14. Carbonyl protection and deprotection is also important. Yoshihisa Kobayashi of the University of California, San Diego has devised (J. Org. Chem. 2007, 72, 3913) the isonitrile 15. Usually, the product 16 after Ugi condensation would be very difficult to hydrolyze. In the case of 16, mild acid effected cyclization to the acyl indole 17, which was easy to hydrolyze. In a different approach, Francesco Naso of the Università di Bari has shown (Chem. Commun. 2007, 3756) that acid chlorides such as 18 condensed with 19 to give the furan 20. Such furans are easily oxidized, liberating the starting acid.

scholarly journals Ecological Media Studies and the Matter of Digital Technologies

PMLA ◽  
2016 ◽  
Vol 131 (2) ◽  
pp. 364-372
Author(s):  
Allison Carruth
Keyword(s):  
Los Angeles ◽  
Digital Humanities ◽  
University Of California ◽  
Public Higher Education ◽  
Environmental Humanities ◽  
University Of Utah ◽  
Princeton University ◽  
Institute Of Technology ◽  
Cultural Responses ◽  
The University

In 2009 william pannapacker pronounced the digital humanities to be “the first ‘next big thing’ in a longtime” promising to reconfigure and reinvigorate the humanities. The same could now plausibly be said about the environmental humanities with the recent rise of dedicated academic centers (at, e.g., KTH Royal Institute of Technology, in Sweden; Princeton University; the University of California, Santa Barbara; and the University of Utah), grant-funded projects (like the Sawyer Seminar on the Environmental Humanities at the University of California, Los Angeles, and the consortium Humanities for the Environment), and faculty positions. If the digital and environmental humanities have been ascendant amid what Christopher Newfield describes as the “unmaking” of public higher education and what Richard Grusin terms the “crisis humanities,” such an assessment invites the question of whether the ecological digital humanities (EcoDH) might serve to combine the most saleable facets of the digital humanities and the environmental humanities for university stakeholders who promote applied humanities work outside academia or, alternatively, a hybrid method for researching, teaching, and designing cultural responses to structures of ecological and social precarity (Grusin 80).

The impact of publications in core public choice journals: an analysis of institution rankings

2021 ◽  
Author(s):  
Franklin G. Mixon ◽  
Kamal P. Upadhyaya
Keyword(s):  
Public Choice ◽  
University Of Illinois ◽  
Oxford University ◽  
University Of Oxford ◽  
University Of Cambridge ◽  
Emory University ◽  
University Of Göttingen ◽  
The University ◽  
The Impact ◽  
Published Research

This study examines the impact of research published in the two core public choice journals – Public Choice and the Journal of Public Finance and Public Choice – during the five-year period from 2010 through 2014. Scholars representing almost 400 universities contributed impactful research to these journals over this period, allowing us to rank institutions on the basis of citations to this published research. Our work indicates that public choice scholarship emanating from non-US colleges and universities has surged, with the University of Göttingen, University of Linz, Heidelburg University, University of Oxford, University of Konstanz, Aarhus University, University of Groningen, Paderborn University, University of Minho and University of Cambridge occupying ten of the top 15 positions in our worldwide ranking. Even so, US-based institutions still maintain a lofty presence, with Georgetown University, Emory University, the University of Illinois and George Mason University each holding positions among the top five institutions worldwide.

William Alfred Shack

2018 ◽  
pp. 27-36
Author(s):  
Dallas L. Browne
Keyword(s):  
Graduate Students ◽  
Field Research ◽  
University Of California ◽  
University Of Illinois ◽  
Distinguished Career ◽  
The University

This chapter focuses on the life and accomplishments of Africanist anthropologist William Shack. Known to all as Shack, he had a career that included field research in Ethiopia and Swaziland, teaching in African universities as well as at the University of Illinois and the University of California, Berkeley. This chapter can offer hope and encouragement to graduate students of anthropology who may be in departments that are not as supportive or encouraging as they might wish, because William Shack faced major obstacles in completing his Ph.D. Despite the obstacles he faced, Shack went on to a distinguished career as an anthropologist and university administrator.

Using Mammon for Righteousness

2017 ◽  
Author(s):  
Joan Marie Johnson
Keyword(s):  
University Of California ◽  
Massachusetts Institute ◽  
Massachusetts Institute Of Technology ◽  
Access To Education ◽  
Intellectual Achievement ◽  
Institute Of Technology ◽  
The University

Chapter 5 explores what happened when women approached existing coeducational schools offering restricted gifts to benefit women. These donations either forced a school to open its doors to women or increased the number of women admitted by providing scholarships for women or erecting a women’s building or a women’s dormitory. Like the college founders, these donors believed that women were capable of the same intellectual achievement as men but found that many of America’s best universities resisted coeducation. The women in this chapter, including Mary Garrett, and Phoebe Hearst and the gifts they gave show how money could be wielded to force changes that would benefit women, in the form of access to education and professions formerly restricted to men. Moreover, coeducation at these schools, including Johns Hopkins, Massachusetts Institute of Technology, and the University of California, Berkeley, was especially significant. If women were welcomed at these important institutions, they could demonstrate their intellectual and professional capabilities and equality with men.

Synthesis of Substituted Benzenes: The Carter Synthesis of Siamenol

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Aryl Halides ◽  
Substituted Benzenes ◽  
Diversity Oriented Synthesis ◽  
University Of Illinois ◽  
University Of Houston ◽  
Direct Functionalization ◽  
University Of Edinburgh ◽  
Aryl Tosylates ◽  
La Jolla ◽  
The University

Tosylates are among the least expensive, but also among the least reactive toward Pd(0) oxidative addition, of aryl sulfonates. Jie Wu of Fudan University has now devised conditions (J. Org. Chem. 2007, 72, 9346) for the Pd-catalyzed coupling of aryl tosylates such as 1 with arene trifluoroborates. Kei Manabe of RIKEN has found (Organic Lett. 2007, 9, 5593) that an ortho OH activates an adjacent Cl for Pd-mediated coupling, allowing the conversion of 4 to 6 . Philippe Uriac and Pierre van de Weghe of the Université de Rennes I have developed (Organic Lett. 2007, 9, 3623) conditions for the catalytic acylation of aryl halides with alkenyl acetates such as 8. Multi-component coupling lends itself well to diversity-oriented synthesis. As illustrated by the combination of 10 with 11 and 12 to give 13 reported (Organic Lett. 2007, 9, 5589) by Michael F. Greaney of the University of Edinburgh, benzynes can do double addition with high regiocontrol. For other recent references to unsymmetrical double additions to arynes, see Angew.Chem. Int. Ed. 2007, 46, 5921; Chem. Commun. 2007, 2405; and J. Am. Chem. Soc. 2006, 128, 14042. C-H functionalization of arenes is of increasing importance. John F. Hartwig of the University of Illinois has described (Organic Lett. 2007, 9, 757; 761) improved conditions for Ir-catalyzed meta borylation, and conditions for further coupling of the initial borate 16 to give amines such as 17. Lei Liu and Qing-Xiang Guo of the University of Science and Technology, Hefei have found (Tetrahedron Lett. 2007, 48, 5449) that oxygen can be used as the stoichiometric oxidant in the Pd-catalyzed functionalization of H’s ortho to anilides. Two other research groups (J. Am. Chem. Soc. 2007, 129, 6066; Angew. Chem. Int. Ed. 2007, 46, 5554; J. Org. Chem. 2007, 72, 7720) reported advances in this area. In a close competition, Jin-Quan Yu, now at Scripps/La Jolla (J. Am. Chem. Soc. 2007, 129, 3510) and Olafs Daugulis of the University of Houston (J. Am. Chem. Soc. 2007, 129, 9879) both reported that a carboxyl group can activate an ortho H for direct functionalization.

Functionalization of C-H Bonds: The Baran Synthesis of Dihydroxyeudesmane

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Columbia University ◽  
National Chemical Laboratory ◽  
Chemical Laboratory ◽  
Du Bois ◽  
Rh Catalyst ◽  
Hydride Abstraction ◽  
Mcgill University ◽  
Radical Removal ◽  
The University ◽  
Useful Yield

Arumugam Sudalai of the National Chemical Laboratory, Pune reported (Tetrahedron Lett. 2008, 49, 6401) a procedure for hydrocarbon iodination. With straight chain hydrocarbons, only secondary iodination was observed. Chao-Jun Li of McGill University uncovered (Adv. Synth. Cat. 2009, 351, 353) a procedure for direct hydrocarbon amination, converting cyclohexane 1 into the amine 3. Justin Du Bois of Stanford University established (Angew. Chem. Int. Ed. 2009, 48, 4513) a procedure for alkane hydroxylation, converting 4 selectively into the alcohol 6. The oxirane 8 usually also preferentially ozidizes methines, hydroxylating steroids at the C-14 position. Ruggero Curci of the University of Bari found (Tetrahedron Lett. 2008, 49, 5614) that the substrate 7 showed some C-14 hydroxylation, but also a useful yield of the ketone 9. The authors suggested that the C-7 acetoxy group may be deactivating the C-14 C-H. C-H bonds can also be converted directly to carbon-carbon bonds. Mark E. Wood of the University of Exeter found (Tetrahedron Lett. 2009, 50, 3400) that free-radical removal of iodine from 10 followed by intramolecular H-atom abstraction in the presence of the trapping agent 11 delivered 12 with good diastereo control. Professor Li observed (Angew. Chem. Int. Ed. 2008, 47, 6278) that under Ru catalysis, hydrocarbons such as 13 could be directly arylated. He also established (Tetrahedron Lett. 2008, 49, 5601) conditions for the direct aminoalkylation of hydrocarbons such as 13, to give 17. Huw M. L. Davies of Emory University converted (Synlett 2009, 151) the ester 4 to the homologated diester 19 in preparatively useful yield using the diazo ester 18, the precursor to a selective, push-pull stabilized carbene. Intramolecular bond formation to an unactivated C-H can be even more selective. Guoshen Liu of the Shanghai Institute of Organic Chemistry developed (Organic Lett. 2009, 11, 2707) an oxidative Pd system that cyclized 20 to the seven-membered ring lactam 21 . Professor Du Bois devised (J. Am. Chem. Soc. 2008 , 130, 9220) a Rh catalyst that effected allylic amination of 22, to give 23 with substantial enantiocontrol. Dalibor Sames of Columbia University designed (J. Am. Chem. Soc. 2009, 131, 402) a remarkable cascade approach to C-H functionalization. Exposure of 24 to Lewis acid led to intramolecular hydride abstraction. Cyclization of the resulting stabilized carbocation delivered the tetrahydropyan 25 with remarkable diastereocontrol.

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