scholarly journals Modular Terpene Synthesis Enabled by Mild Electrocatalytic Couplings

2021 ◽  
Author(s):  
Stephen Harwood ◽  
Maximilian Palkowitz ◽  
Cara Gannett ◽  
Paulo Perez ◽  
Zhen Yao ◽  
...  
Keyword(s):  
Modular Design ◽  
Modified Electrodes ◽  
Analytical Techniques ◽  
Large Field ◽  
Coupling Reactions ◽  
Terpene Biosynthesis ◽  
Decarboxylative Coupling ◽  
History Of ◽  
Terpene Synthesis

The synthesis of terpenes is a large field of research that is woven deeply into the history of chemistry. Terpene biosynthesis is a case-study of how the logic of a modular design can lead to diverse structures with unparalleled efficiency. This work mimics Nature by leveraging modern Ni-catalyzed electrochemical sp2–sp3 decarboxylative coupling reactions—enabled by Ag-nanoparticle modified electrodes—to intuitively assemble terpene natural products and complex polyenes. The step-change in efficiency of this approach is exemplified through the scalable preparation of 13 complex terpenes, which minimized protecting group manipulations, functional group interconversions, and redox fluctuations. Finally, the mechanistic aspects of the essential functionalized electrodes are studied in depth through a variety of spectroscopic and analytical techniques.

scholarly journals Modular Terpene Synthesis Enabled by Mild Electrocatalytic Couplings

2021 ◽  
Author(s):  
Stephen Harwood ◽  
Maximilian Palkowitz ◽  
Cara Gannett ◽  
Paulo Perez ◽  
Zhen Yao ◽  
...  
Keyword(s):  
Modular Design ◽  
Modified Electrodes ◽  
Analytical Techniques ◽  
Large Field ◽  
Coupling Reactions ◽  
Terpene Biosynthesis ◽  
Decarboxylative Coupling ◽  
History Of ◽  
Terpene Synthesis

The synthesis of terpenes is a large field of research that is woven deeply into the history of chemistry. Terpene biosynthesis is a case-study of how the logic of a modular design can lead to diverse structures with unparalleled efficiency. This work mimics Nature by leveraging modern Ni-catalyzed electrochemical sp2–sp3 decarboxylative coupling reactions—enabled by Ag-nanoparticle modified electrodes—to intuitively assemble terpene natural products and complex polyenes. The step-change in efficiency of this approach is exemplified through the scalable preparation of 13 complex terpenes, which minimized protecting group manipulations, functional group interconversions, and redox fluctuations. Finally, the mechanistic aspects of the essential functionalized electrodes are studied in depth through a variety of spectroscopic and analytical techniques.

Press Propaganda and Subaltern Agents of Pan-Islamic Networks in the Muslim Mediterranean World prior to World War I

2018 ◽  
Author(s):  
Odile Moreau
Keyword(s):  
Middle East ◽  
World War I ◽  
North Africa ◽  
World War ◽  
Subaltern Studies ◽  
Resistance Movements ◽  
The Press ◽  
Mediterranean World ◽  
History Of

This chapter explores movement and circulation across the Mediterranean and seeks to contribute to a history of proto-nationalism in the Maghrib and the Middle East at a particular moment prior to World War I. The discussion is particularly concerned with the interface of two Mediterranean spaces: the Middle East (Egypt, Ottoman Empire) and North Africa (Morocco), where the latter is viewed as a case study where resistance movements sought external allies as a way of compensating for their internal weakness. Applying methods developed by Subaltern Studies, and linking macro-historical approaches, namely of a translocal movement in the Muslim Mediterranean, it explores how the Egypt-based society, al-Ittihad al-Maghribi, through its agent, Aref Taher, used the press as an instrument for political propaganda, promoting its Pan-Islamic programme and its goal of uniting North Africa.

Turning Aliens into Socialists

2010 ◽  
Vol 1 (1) ◽  
pp. 75-93
Author(s):  
Jessica Moberg
Keyword(s):  
Outer Space ◽  
The United States ◽  
Second World War ◽  
World War ◽  
History Of ◽  
Swedish History ◽  
Second World ◽  
The Universe ◽  
Highly Evolved

Immediately after the Second World War Sweden was struck by a wave of sightings of strange flying objects. In some cases these mass sightings resulted in panic, particularly after authorities failed to identify them. Decades later, these phenomena were interpreted by two members of the Swedish UFO movement, Erland Sandqvist and Gösta Rehn, as alien spaceships, or UFOs. Rehn argued that ‘[t]here is nothing so dramatic in the Swedish history of UFOs as this invasion of alien fly-things’ (Rehn 1969: 50). In this article the interpretation of such sightings proposed by these authors, namely that we are visited by extraterrestrials from outer space, is approached from the perspective of myth theory. According to this mythical theme, not only are we are not alone in the universe, but also the history of humankind has been shaped by encounters with more highly-evolved alien beings. In their modern day form, these kinds of ideas about aliens and UFOs originated in the United States. The reasoning of Sandqvist and Rehn exemplifies the localization process that took place as members of the Swedish UFO movement began to produce their own narratives about aliens and UFOs. The question I will address is: in what ways do these stories change in new contexts? Texts produced by the Swedish UFO movement are analyzed as a case study of this process.

Metal-Organic Frameworks vs. Buffers: Case Study of UiO-66 Stability

2020 ◽  
Author(s):  
Daniel Bůžek ◽  
Slavomír Adamec ◽  
Kamil Lang ◽  
Jan Demel
Keyword(s):  
Inductively Coupled Plasma ◽  
Buffer Capacity ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Analytical Techniques ◽  
Aqueous Dispersions ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Metal Organic

<div><p>UiO-66 is a zirconium-based metal-organic framework (MOF) that has numerous applications. Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature. The present work therefore assessed the behaviour of UiO-66 in buffers: 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS), 4-(2-hydroxyethyl)piperazine-1-ethane sulfonic acid (HEPES), N-ethylmorpholine (NEM) and phosphate buffer (PB), all of which are commonly used in many UiO-66 applications. High pressure liquid chromatography and inductively coupled plasma mass spectrometry were used to monitor degradation of the MOF. In each buffer, the terephthalate linker was released to some extent, with a more pronounced leaching effect in the saline forms of these buffers. The HEPES buffer was found to be the most benign, whereas NEM and PB should be avoided at any concentration as they were shown to rapidly degrade the UiO-66 framework. Low concentration TRIS buffers are also recommended, although these offer minimal buffer capacity to adjust pH. Regardless of the buffer used, rapid terephthalate release was observed, indicating that the UiO-66 was attacked immediately after mixing with the buffer. In addition, the dissolution of zirconium, observed in some cases, intensified the UiO-66 decomposition process. These results demonstrate that sensitive analytical techniques have to be used to monitor the release of MOF components so as to quantify the stabilities of these materials in liquid environments.</p></div>

A Case Study on the Process of Creating Interests in History of History-Deokhu

2019 ◽  
Vol 58 (1) ◽  
pp. 147-159
Author(s):  
Young-Seok Seo ◽  
Bong-Seok Kim
Keyword(s):  
History Of

Scales and Units

2018 ◽  
Author(s):  
Kathryn M. de Luna
Keyword(s):  
Language Change ◽  
Historical Linguistics ◽  
Bantu Languages ◽  
The North ◽  
First Case ◽  
Linguistic Evidence ◽  
River Region ◽  
History Of ◽  
Alternative Approaches

This chapter uses two case studies to explore how historians study language movement and change through comparative historical linguistics. The first case study stands as a short chapter in the larger history of the expansion of Bantu languages across eastern, central, and southern Africa. It focuses on the expansion of proto-Kafue, ca. 950–1250, from a linguistic homeland in the middle Kafue River region to lands beyond the Lukanga swamps to the north and the Zambezi River to the south. This expansion was made possible by a dramatic reconfiguration of ties of kinship. The second case study explores linguistic evidence for ridicule along the Lozi-Botatwe frontier in the mid- to late 19th century. Significantly, the units and scales of language movement and change in precolonial periods rendered visible through comparative historical linguistics bring to our attention alternative approaches to language change and movement in contemporary Africa.

Case Study: Rome's House of Memory and History: The Politics of Memory and Public Institutions

2012 ◽  
Author(s):  
Alessandro Portelli
Keyword(s):  
Oral History ◽  
Cultural Policy ◽  
Public Institutions ◽  
Politics Of Memory ◽  
Political Events ◽  
History Of ◽  
Ambitious Program ◽  
The City

This article centers around the case study of Rome's House of Memory and History to understand the politics of memory and public institutions. This case study is about the organization and politics of public memory: the House of Memory and History, established by the city of Rome in 2006, in the framework of an ambitious program of cultural policy. It summarizes the history of the House's conception and founding, describes its activities and the role of oral history in them, and discusses some of the problems it faces. The idea of a House of Memory and History grew in this cultural and political context. This article traces several political events that led to the culmination of the politics of memory and its effect on public institutions. It says that the House of Memory and History can be considered a success. A discussion on a cultural future winds up this article.

The Wolf Man’s Glückshaube: Rereading Sergei Pankejeff’s Memoir

2019 ◽  
Vol 67 (5) ◽  
pp. 789-814
Author(s):  
Anat Tzur Mahalel
Keyword(s):  
Complex Matrix ◽  
Neurotic Symptom ◽  
History Of ◽  
The Veil ◽  
Wolf Man

A comparative reading of Freud’s canonical case study “From the History of an Infantile Neurosis” (1918) and the memoir written by the protagonist of that study, Sergei Pankejeff, known as the Wolf Man (1971a), centers on the complex matrix of meanings embodied in the act of lifting the veil. The neurotic symptom of a veil seemingly in front of the analysand’s eyes is interpreted by Freud as a repetition of his birth in a Glückshaube (German for “caul,” literally a “lucky hood”). The veil is represented as an ambivalent object both for Freud and for Pankejeff, who are enticed by the sense of a final truth behind the veil yet constantly doubt the possibility of grasping it. For Freud, psychoanalysis is the very process of lifting the veil, yet his analysand remained for him an unsolved riddle. Pankejeff, in a volume dedicated to his identity as the Wolf Man (Gardiner 1971a), created an autobiographical text that deliberately avoids telling the story of the analysand, thus drawing a veil over his story. The paradox embodied in lifting the veil is discussed in relation to Walter Benjamin’s distinction between materiality and truth and his notion of the inherent unity of the veil and the veiled (1925).

Sign in / Sign up

Export Citation Format

Share Document