scholarly journals Palladium-Catalysed Construction of All-Carbon Quaternary Centres with Propargylic Electrophiles: Challenges in the Simultaneous Control of Regio-, Chemo- and Enantioselectivity

Synthesis ◽  
2018 ◽  
Vol 50 (09) ◽  
pp. 1796-1814 ◽  
Author(s):  
Vilius Franckevičius ◽  
Miles Kenny ◽  
Sybrin Schröder ◽  
Nicholas Taylor ◽  
Paula Jackson ◽  
...  
Keyword(s):  
Careful Analysis ◽  
Single Step ◽  
The Other ◽  
Allylic Alkylation ◽  
Dicarbonyl Compounds ◽  
Simultaneous Control ◽  
C And N ◽  
Coupling Partner ◽  
Three Component Coupling

This article describes the palladium-catalysed three-component coupling of 1,3-dicarbonyl compounds with nucleophiles and propargylic electrophiles for the generation of quaternary all-carbon centres in a single step, which necessitates the simultaneous control of regio-, chemo- and enantioselectivity. The use of propargyl enol carbonates, the source of two of the components, was found to be essential in maintaining high levels of regiocontrol and chemoselectivity, whereas a careful analysis of pK a trends of O-, C- and N-nucleophiles as the other coupling partner indicates that the highest levels of selectivity are likely to be obtained with relatively acidic species, such as phenols, 1,3-dicarbonyl compounds and aromatic N-heterocycles. Finally, studies towards the development of the catalytic enantioselective construction of quaternary all-carbon centres by means of alkenylation and allylic alkylation are disclosed.

Camus's Absurd and the World of Melville's Confidence-Man

PMLA ◽  
1967 ◽  
Vol 82 (1) ◽  
pp. 14-27
Author(s):  
Leon F. Seltzer
Keyword(s):  
Careful Analysis ◽  
The Other ◽  
The Novel ◽  
The Past ◽  
The World ◽  
Critical Attention ◽  
Confidence Man ◽  
Ugly Duckling ◽  
History Of ◽  
The One

In recent years, The Confidence-Man: His Masquerade, a difficult work and for long an unjustly neglected one, has begun to command increasingly greater critical attention and esteem. As more than one contemporary writer has noted, the verdict of the late Richard Chase in 1949, that the novel represents Melville's “second best achievement,” has served to prompt many to undertake a second reading (or at least a first) of the book. Before this time, the novel had traditionally been the one Melville readers have shied away from—as overly discursive, too rambling altogether, on the one hand, or as an unfortunate outgrowth of the author's morbidity on the other. Elizabeth Foster, in the admirably comprehensive introduction to her valuable edition of The Confidence-Man (1954), systematically traces the history of the book's reputation and observes that even with the Melville renaissance of the twenties, the work stands as the last piece of the author's fiction to be redeemed. Only lately, she comments, has it ceased to be regarded as “the ugly duckling” of Melville's creations. But recognition does not imply agreement, and it should not be thought that in the past fifteen years critics have reached any sort of unanimity on the novel's content. Since Mr. Chase's study, which approached the puzzling work as a satire on the American spirit—or, more specifically, as an attack on the liberalism of the day—and which speculated upon the novel's controlling folk and mythic figures, other critics, by now ready to assume that the book repaid careful analysis, have read the work in a variety of ways. It has been treated, among other things, as a religious allegory, as a philosophic satire on optimism, and as a Shandian comedy. One critic has conveniently summarized the prevailing situation by remarking that “the literary, philosophical, and cultural materials in this book are fused in so enigmatic a fashion that its interpreters have differed as to what the book is really about.”

MONISMO PREDICAZIONALE SUI LIMITI DI UN’INTERPRETAZIONE EPISTEMOLOGICA DELL’ELEATISMO

Méthexis ◽  
2010 ◽  
Vol 23 (1) ◽  
pp. 5-33
Author(s):  
MASSIMO PULPITO
Keyword(s):  
20Th Century ◽  
Careful Analysis ◽  
Fundamental Question ◽  
The Other ◽  
Traditional View ◽  
Profound Influence ◽  
The One

Today, the field of Parmenidean studies is still divided over the fundamental question of the correct exegesis of the verb 'to be' in the poem On Nature. The two principal interpretative lines supported by scholars are, on the one hand, the traditional view that understands the verb ‘to be’ in its existential sense and, on the other, the one that arose in the 20th century that focuses on its predicative sense. This paper examines the latest and most ambitious attempt to interpret the thought of Parmenides and the profound influence that he had on pluralist philosophers, starting from a purely predicative approach. It is an epistemological interpretation of the Eleaticism proposed by Patricia Curd, centred on the notion of ‘predicational monism’, which has the unquestionable merit to place Parmenides within the pre-Socratic naturalistic debate but that, after a careful analysis, fails to convince. In fact, this interpretation, which certainly appears to be one of the most articulate and intelligent proposals of recent years, raises a series of exegetical and argumentative problems that do not seem possible to resolve without exiting the predicative horizon.

scholarly journals Et3B-mediated two- and three-component coupling reactions via radical decarbonylation of α-alkoxyacyl tellurides: single-step construction of densely oxygenated carboskeletons

2015 ◽  
Vol 6 (5) ◽  
pp. 2765-2769 ◽  
Author(s):  
Masanori Nagatomo ◽  
Daigo Kamimura ◽  
Yuki Matsui ◽  
Keisuke Masuda ◽  
Masayuki Inoue
Keyword(s):  
Single Step ◽  
Coupling Reactions ◽  
One Step ◽  
Sugar Derivatives ◽  
Three Component Coupling

We devised new radical-based two- and three-component coupling reactions of sugar derivatives, and realized one-step construction of contiguously substituted polyol structures.

Visual Mental Rotation: Different Processes Used by Pilots

1992 ◽  
Vol 36 (18) ◽  
pp. 1368-1372
Author(s):  
Itiel E. Dror
Keyword(s):  
Mental Rotation ◽  
Single Step ◽  
The Other ◽  
Angular Rotation ◽  
Small Perturbations ◽  
Starting Position ◽  
Control Subjects ◽  
Complex Stimuli ◽  
And Control ◽  
Incremental Rotation

Air Force pilots and control subjects were tested on a visual “mental rotation” task. Nine of the 16 pilots, as well as all of the 16 control subjects, required more time to rotate greater angular distances. The performance of the other 7 pilots was unique: their response time did not increase with greater angular rotations. The results suggest that visual mental rotation can be accomplished by at least two different processes. One process involves incremental object rotations in a multi-step mapping –like an actual physical rotation of an object– going through intermediate stages. This process requires more time to rotate greater angular distances. The other process involves direct translation in a single-step mapping. In this process, the starting position transforms into the final position in one mapping without any intermediate steps, and thus does not require more time to rotate greater angular rotation. The lack of intermediate stages, which may allow small perturbations in location to be corrected, affects the accuracy of this process; this is particularly apparent when more complex stimuli are rotated. The pilots who did not show incremental rotation effects had different and distinct error patterns, their errors increased when rotating the more complex stimuli.

Single-Step Synthesis of 5,6,7,8-Tetrahydroindolizines via Annulation of 2-Formylpiperidine and 1,3-Dicarbonyl Compounds

2015 ◽  
Vol 17 (14) ◽  
pp. 3564-3567 ◽  
Author(s):  
Simona S. Capomolla ◽  
Ngiap-Kie Lim ◽  
Haiming Zhang
Keyword(s):  
Single Step ◽  
Dicarbonyl Compounds

Types of Negation

2020 ◽  
pp. 57-74
Author(s):  
Karen De Clercq
Keyword(s):  
Critical Review ◽  
Careful Analysis ◽  
The Other ◽  
Fine Grained ◽  
Other Hand ◽  
The One

This chapter discusses the well-known dichotomies between sentence negation and constituent negation on the one hand and external negation and internal negation on the other hand. It explains how the notions differ and where they show overlap. Crucial in this discussion is the presentation and critical review of some of the most relevant tests for negation as discussed by Klima (1964). The discussion leads to the observation that both sentence negation and constituent negation are umbrella terms for multiple scopal types of negation. The chapter further shows how a careful analysis of negative morphology can be insightful in putting up a more fine-grained classification that does better justice to the reality of negative markers than captured by the well-known dichotomies.

scholarly journals Oxidative Photocatalytic Homo- and Cross-Coupling of Phenols: Non-Enzymatic, Catalytic Method for Coupling Tyrosine

2020 ◽  
Author(s):  
Kyle Niederer ◽  
Philip H. Gilmartin ◽  
Marisa Kozlowski
Keyword(s):  
High Selectivity ◽  
Cross Coupling ◽  
The Other ◽  
Nucleophilic Attack ◽  
Coupling Reactions ◽  
Catalytic Method ◽  
Cross Coupling Reactions ◽  
Oxidation Potentials ◽  
Coupling Partner ◽  
Radical Form

The first, oxidative photocatalytic method for phenol-phenol homo-coupling and cross-coupling is described and isolated yields of up to 97% are obtained. Measured oxidation potentials and computed nucleophilicity parameters are consistent with a nucleophilic attack of one partner onto the oxidized radical form of the other partner. Understanding of this model permitted development of cross-coupling reactions between nucleophilic phenols/arenes and easily oxidized phenols in high selectivity and efficiency. A highlight of this method is that one equivalent of each coupling partner is utilized. Building on these findings, the first non-enzymatic, catalytic method for coupling tyrosine was developed.

scholarly journals CONCEPT OF NATIONALISM EMPLOYED IN THE GOLDEN LEGEND BY NADEEM ASLAM

2021 ◽  
Vol 9 (4) ◽  
pp. 41-47
Author(s):  
Shaista Shahzadi ◽  
Muhammad Hanif ◽  
Ali Ahmad ◽  
Hira Ali ◽  
Mehnaz Kousar
Keyword(s):  
Careful Analysis ◽  
The Other ◽  
Imagined Communities ◽  
The Political ◽  
The Novel ◽  
Basic Resource ◽  
The World ◽  
Benedict Anderson ◽  
Golden Legend ◽  
Entire Text

Purpose of the study: The main purpose of this study is to analyze the novel The Golden Legend by Nadeem Aslam in the light of the concept of Nationalism given by Benedict Anderson in Imagined communities. Methodology: The entire data is evaluated by the entire text related to nationalism. This research is based on qualitative research skills. The basic resource of this research is the novel of Nadeem Aslam, named The Golden Legend. Further, the other resources used in this research are the journals or the articles regarding or reflecting the explanation of this novel (The Golden Legend). Main Findings: The findings depict a wonderful series of characters who have humanity in their hearts; they have love and respect for others, either the other person is from their religion or a different one. It is a story of sorrow and the game of religions in the world which is being played under the acts of the political authorities. Applications of this study: This study can be applied to the nationalism literature. Novelty/Originality of this study: The study is one of its kind because, after a careful analysis of the literature available, it is safe to say that no study is done up till now on analyzing the concept of nationalism in the Golden Legend.

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