Wide Scope in situ

2013 ◽  
Author(s):  
Wolfgang Sternefeld
Keyword(s):  
Wide Scope

Echo Questions in the Minimalist Program

2010 ◽  
Vol 41 (1) ◽  
pp. 131-148 ◽  
Author(s):  
Nicholas Sobin
Keyword(s):  
Minimalist Program ◽  
Wide Scope ◽  
Verb Movement ◽  
Question Formation ◽  
Scope Assignment ◽  
Echo Questions

English echo questions present numerous challenges to the analysis of interrogatives, including (a) simple wh-in-situ (You saw who?); (b) apparent Superiority violations (What did who see?); (c) apparent verb movement without wh-movement (Has Mary seen what?); and (d) requisite wide scope only for echo-question-introduced wh-phrases (underlined in these examples—only who in What did who see? is being asked about). Such apparently contrary features may be explained in terms of independently necessary scope assignment mechanisms and a complementizer that subordinates the utterance being echoed and “freezes” its CP structure. No norms of question formation are violated.

scholarly journals Dearomative Photocatalytic Construction of Bridged 1,3-Diazepanes

2019 ◽  
Author(s):  
Jamie Leitch ◽  
Tatiana Rogova ◽  
Fernanda Duarte ◽  
Darren J. Dixon
Keyword(s):  
Reaction Mechanism ◽  
Radical Addition ◽  
Ring Closure ◽  
Natural Product Synthesis ◽  
Quinoline Derivatives ◽  
Wide Scope ◽  
Mechanistic Studies ◽  
Good Efficiency ◽  
Quaternary Centers

The construction of diverse sp3-rich skeletal ring systems is of importance to drug discovery programmes and natural product synthesis. Herein, we report the photocatalytic construction of 2,7-diazabicyclo[3.2.1]octanes (bridged 1,3-diazepanes) via a reductive diversion of the Minisci reaction. The fused tricyclic product is proposed to form via radical addition to the C4 position of 4-substituted quinoline substrates, with subsequent Hantzsch ester-promoted reduction to a dihydropyridine intermediate which undergoes in situ two-electron ring closure to form the bridged diazepane architecture. A wide scope of N-arylimine and quinoline derivatives was demonstrated and good efficiency was observed in the construction of sterically congested all-carbon quaternary centers. Computational and experimental mechanistic studies provide insights into the reaction mechanism and observed regioselectivity/diastereoselectivity.<br>

scholarly journals Dearomative Photocatalytic Construction of Bridged 1,3-Diazepanes

2019 ◽  
Author(s):  
Jamie Leitch ◽  
Tatiana Rogova ◽  
Fernanda Duarte ◽  
Darren J. Dixon
Keyword(s):  
Reaction Mechanism ◽  
Radical Addition ◽  
Ring Closure ◽  
Natural Product Synthesis ◽  
Quinoline Derivatives ◽  
Wide Scope ◽  
Mechanistic Studies ◽  
Good Efficiency ◽  
Quaternary Centers

The construction of diverse sp3-rich skeletal ring systems is of importance to drug discovery programmes and natural product synthesis. Herein, we report the photocatalytic construction of 2,7-diazabicyclo[3.2.1]octanes (bridged 1,3-diazepanes) via a reductive diversion of the Minisci reaction. The fused tricyclic product is proposed to form via radical addition to the C4 position of 4-substituted quinoline substrates, with subsequent Hantzsch ester-promoted reduction to a dihydropyridine intermediate which undergoes in situ two-electron ring closure to form the bridged diazepane architecture. A wide scope of N-arylimine and quinoline derivatives was demonstrated and good efficiency was observed in the construction of sterically congested all-carbon quaternary centers. Computational and experimental mechanistic studies provide insights into the reaction mechanism and observed regioselectivity/diastereoselectivity.<br>

scholarly journals Analysing Appreciating and Criticizing in Standard Arabic: When Morphology Supports Syntax

2021 ◽  
Vol 3 (1) ◽  
pp. 37-55
Author(s):  
Murdhy Alshamari ◽  
Abdulaziz Albalwi
Keyword(s):  
Positive Attitude ◽  
Ex Situ ◽  
Wide Scope ◽  
Discourse Marker ◽  
Standard Arabic ◽  
State Context

This paper provides a minimalist (Chomsky 2000, 2001) investigation to a syntactic phenomenon slightly analysed in syntactic research on Standard Arabic (SA) literature of poetry (TaqiAldin 1987). This syntactic phenomenon is derived by a construction of a wh-in situ phrase embedded in a construct state phrase (WICS, henceforth). The novelty about this SA WICS phenomenon is that the entity expressed by the wh-phrase is ambiguously assigned two pragmatic values: med? (appreciating) and hid?a? (criticizing). Holding in abeyance with the idea that SA is frozen, having not developed for decades, this research sets a comparative exploration between SA and Saudi variety of Arabic (SDA). It is shown that SDA syntax-pragmatics interface is straightforward. SDA displays WICS, which derives hid?a?, in addition to displaying wh-ex situ phenomenon, which derives med?. In comparison, SA syntax is restricted to WICS phenomenon, which predicts that in construct state context, SA only derives hid?a?, hence, the ambiguity. With minimalist investigation to further articulated structure in the SA data under analysis, the research concludes that the instance of SA WICS is an occurrence of med?, rather than hid?a?. Evidence for this conclusion is based on the observation that, though the occurrence of SA WICS is associated with lack of movement of the wh-phrase, it is simultaneously associated with a wide-scope of the discourse marker wa, which functions as a pragmatic device assigning speaker positive attitude pragmatic value to the proposition. That is to say, SA grammar requires morphology to support syntax with a morphological device when the latter falls short to activate syntactic operations like movement for med? interpretation.

Palladium-catalyzed butoxycarbonylation of (hetero)aryl multibromides-a practical method for the preparation of aryl carboxylate and carboxylic acid

Synthesis ◽  
2021 ◽  
Author(s):  
Weilong Wu ◽  
Yongkang Jing ◽  
Deyi Zhang ◽  
Xianghe Yan ◽  
Rong Liang ◽  
...  
Keyword(s):  
Carboxylic Acids ◽  
Practical Method ◽  
High Yield ◽  
Wide Scope ◽  
Structural Units ◽  
Practical Applications ◽  
Palladium Catalyzed ◽  
Scale Preparation ◽  
New Compounds

The palladium-catalyzed alkoxycarbonylation of (N-hetero)aryl multibromides were investigated systematically. The results show that cheap and readily available in-situ Pd(OAc)2/rac-BINAP catalyst can catalyze butoxycarbonylation of various (N-hetero)aryl multibromides efficiently, and obtain esters with moderate to high yield (59-94% yield). from which, two new compounds (4,4ꞌ-dibutoxycarbonyl-1,1ꞌ-bi-2-naphthol and Di-n-butyl [2,2'-bipyrimidine]-5,5'-dicarboxylate were first reported in this work. In addition, the gram scale preparation of carboxylate and carboxylic acids have be done successful by butoxycarbonylation and hydrolysis reaction. which indicated that the wide scope of substrates and practical applications of the Pd(OAc)2/rac-BINAP catalytic system. Moreover, these carboxylic acids and carboxylate can be used as ligands or structural units to construct MOFs, metal complexes, and COFs etc.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

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