Functional Group Protection

2013 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Secondary Amines ◽  
Primary Amines ◽  
Silyl Ether ◽  
Southern Illinois ◽  
Convenient Procedure ◽  
North Eastern ◽  
National University ◽  
Facile Preparation ◽  
The University

Bekington Myrboh of North-Eastern Hill University reported (Tetrahedron Lett. 2010, 51, 2862) a convenient procedure for the oxidative removal of a 1,3-oxathiolane 1 or a 1,3-dithiolane. Sang-Gyeong Lee and Yong-Jin Yoon of Gyeongsang National University developed (J. Org. Chem. 2010, 75, 484) the pyridazin-3(2H )-one 4 for the microwave-mediated deprotection of an oxime 3. Dario M. Bassani of Université Bordeaux 1 and John S. Snaith of the University of Birmingham devised (J. Org. Chem. 2010, 75, 4648) a procedure for the facile preparation of esters such as 6. Brief photolysis (350 nm) returned the parent carboxylic acid 7. Craig M. Williams of the University of Queensland prepared (Tetrahedron Lett. 2010, 51, 1158) the trithioorthoester 8 by iterative opening of epichlorohydrin. He found that the keto ester 9 could be efficiently released by Hg-mediated hydrolysis. Masatoshi Mihara of the Osaka Municipal Technical Research Institute established (Synlett 2010, 253) that even very congested alcohols such as 10 could be acetylated by acetic anhydride containing a trace of FeCl3. Colleen N. Scott, now at Southern Illinois University, developed (J. Org. Chem. 2010, 75, 253) a convenient procedure for the preparation of the hydridosilane 13, which on Mn catalysis added the alcohol 12 to make the unsymmetrical bisalkoxysilane 14. Sabine Berteina-Raboin of the Université d’Orléans found (Tetrahedron Lett. 2010, 51, 2115) that NaBH4 in EtOH cleanly removed the chloroacetates from 15. Both other esters and silyl ethers were stable under these conditions. Ram S. Mohan of Illinois Wesleyan University established (Tetrahedron Lett. 2010, 51, 1056) that Fe(III) tosylate in methanol selectively removed the alkyl silyl ether from 17 without affecting the aryl silyl ether. Alakananda Hajra and Adinath Majee of Visva-Bharati University effected (Tetrahedron Lett. 2010, 51, 2896) formylation of an amine 19 by heating with commercial 85% formic acid as the solvent in a sealed tube at 80°C. Although both primary and secondary amines could be effi ciently formylated, the primary amines were much more reactive. Doo Ok Jang of Yonsei University found (Tetrahedron Lett. 2010, 51, 683) that the conveniently handled CF3CCO2H (the acid chloride is a gas) could be activated in situ to selectively convert 22 into 24.

C–N Ring Construction: The Waser Synthesis of Jerantinine E

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Ni Catalyst ◽  
University Of Alberta ◽  
Princeton University ◽  
In Situ Preparation ◽  
National University ◽  
The University ◽  
École Polytechnique ◽  
Pais Vasco ◽  
Multicomponent Coupling

James A. Bull of Imperial College London prepared (J. Org. Chem. 2013, 78, 6632) the aziridine 2 with high diastereocontrol by adding the anion of diiodomethane to the imine 1. Karl Anker Jørgensen of Aarhus University observed (Chem. Commun. 2013, 49, 6382) high ee in the distal aziridination of 3 to give 4. Benito Alcaide of the Universidad Complutense de Madrid and Pedro Almendros of ICOQ- CSIC Madrid reduced (Adv. Synth. Catal. 2013, 355, 2089) the β-lactam 5 to the azetidine 6. Hiroaki Sasai of Osaka University added (Org. Lett. 2013, 15, 4142) the allenoate 8 to the imine 7, delivering the azetidine 9 in high ee. Tamio Hayashi of Kyoto University, the National University of Singapore, and A*STAR devised (J. Am. Chem. Soc. 2013, 135, 10990) a Pd catalyst for the enanti­oselective addition of the areneboronic acid 11 to the pyrroline 10 to give 12. Ryan A. Brawn of Pfizer (Org. Lett. 2013, 15, 3424) reported related results. Nicolai Cramer of the Ecole Polytechnique Fédérale de Lausanne developed (J. Am. Chem. Soc. 2013, 135, 11772) a Ni catalyst for the cyclization of the formamide 13 to the lactam 14. Andrew D. Smith of the University of St. Andrews used (Org. Lett. 2013, 15, 3472) an organocatalyst to cyclize 15 to 16. Jose L. Vicario of the Universidad del Pais Vasco effected (Synthesis 2013, 45, 2669) the multicomponent coupling of 17, 18, and 19, mediated by an organocatalyst, to construct 20 in high ee. André Beauchemin of the University of Ottawa explored (J. Org. Chem. 2013, 78, 12735) the thermal cyclization of ω-alkenyl hydroxyl amines such as 21. Abigail G. Doyle of Princeton University developed (Angew. Chem. Int. Ed. 2013, 52, 9153) a Ni catalyst for the enantioselective addition of aryl zinc bromides such as 24 to the pro­chiral 23, to give 25 in high ee. Dennis G. Hall of the University of Alberta developed (Angew. Chem. Int. Ed. 2013, 52, 8069) an in situ preparation of the allyl boronate 26 in high ee. Addition to the aldehyde 27 proceeded with high diasteroselectivity.

Preparation of Benzene Derivatives: The Yu/Baran Synthesis of (+)-Hongoquercin A

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Electrophilic Aromatic Substitution ◽  
University Of Michigan ◽  
Aromatic Substitution ◽  
Blocking Group ◽  
University Of Texas ◽  
University Of Houston ◽  
National University ◽  
Reformatsky Reagent ◽  
The University

Lutz Ackermann of the Georg-August-Universität Göttingen oxidized (Org. Lett. 2013, 15, 3484) the anisole derivative 1 to the phenol 2. Melanie S. Sanford of the University of Michigan devised (Org. Lett. 2013, 15, 5428) complementary condi­tions for either para acetoxylation of 3, illustrated, to give 4, or meta acetoxylation. Lukas J. Goossen of the Technische Universität Kaiserlautern developed (Synthesis 2013, 45, 2387) conditions for the cascade alkoxylation/decarboxylation of 5 to give 6. Cheol-Hong Cheon of Korea University showed (J. Org. Chem. 2013, 78, 12154) that the boronic acid of 7 could act as a blocking group during electrophilic aromatic substitution or, as illustrated, as an ortho directing group. It could then be removed by protodeboronation, leading to 8. Jun Wu of Zhejiang University coupled (Synlett 2013, 24, 1448) the phenol 9 with the bromo amide 10 to give an ether that, on exposure to KOH at elevated temperature, rearranged to the intermediate amide, that was then hydrolyzed to 11. Dong-Shoo Shin of Changwon National University reported (Tetrahedron Lett. 2013, 54, 5151) a similar protocol (not illustrated) to prepare unsubsti­tuted anilines. Guangbin Dong of the University of Texas, Austin used (J. Am. Chem. Soc. 2013, 135, 18350) a variation on the Catellani reaction to add 13 to the ortho bromide 12 to give the meta amine 14. Kei Manabe of the University of Shizuoka found (Angew. Chem. Int. Ed. 2013, 52, 8611) that the crystalline N-for­myl saccharin 16 was a suitable CO donor for the carbonylation of the bromide 15 to the aldehyde 17. John F. Hartwig of the University of California, Berkeley described (J. Org. Chem. 2013, 78, 8250) the coupling of the zinc enolate of an ester (Reformatsky reagent), either preformed or generated in situ, with an aryl bromide 18 to give 19. Olafs Daugulis of the University of Houston developed (Org. Lett. 2013, 15, 5842) conditions for the directed ortho phenoxylation of 20 with 21 to give 22. Yao Fu of the University of Science and Technology of China effected (J. Am. Chem. Soc. 2013, 135, 10630) directed ortho cyanation of 23 with 24 to give 25.

Reactions of Alkenes

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Iron Catalyst ◽  
Catalytic Reduction ◽  
Indian Institute ◽  
Yale University ◽  
Terminal Alkene ◽  
National University ◽  
Institute Of Technology ◽  
La Jolla ◽  
The University

The catalytic reduction of the alkene 1 gave the cis-fused product (not illustrated), by kinetic H₂ addition to the less congested face of the alkene. Ryan A. Shenvi of Scripps La Jolla found (J. Am. Chem. Soc. 2014, 136, 1300) conditions for stepwise HAT, con­verting 1 to the thermodynamically-favored trans-fused ketone 2. Seth B. Herzon of Yale University devised (J. Am. Chem. Soc. 2014, 136, 6884) a protocol for the reduc­tion, mediated by 4, of the double bond of a haloalkene 3 to give the saturated halide 5. The Shenvi conditions also reduced a haloalkene to the saturated halide. Daniel J. Weix of the University of Rochester and Patrick L. Holland, also of Yale University, established (J. Am. Chem. Soc. 2014, 136, 945) conditions for the kinetic isomerization of a terminal alkene 6 to the Z internal alkene 7. Christoforos G. Kokotos of the University of Athens showed (J. Org. Chem. 2014, 79, 4270) that the ketone 9, used catalytically, markedly accelerated the Payne epoxidation of 8 to 10. Note that Helena M. C. Ferraz of the Universidade of São Paulo reported (Tetrahedron Lett. 2000, 41, 5021) several years ago that alkene epoxidation was also easily carried out with DMDO generated in situ from acetone and oxone. Theodore A. Betley of Harvard University prepared (Chem. Sci. 2014, 5, 1526) the allylic amine 12 by reacting the alkene 11 with 1-azidoadamantane in the presence of an iron catalyst. Rodney A. Fernandes of the Indian Institute of Technology Bombay developed (J. Org. Chem. 2014, 79, 5787) efficient conditions for the Wacker oxida­tion of a terminal alkene 6 to the methyl ketone 13. Yong-Qiang Wang of Northwest University oxidized (Org. Lett. 2014, 16, 1610) the alkene 6 to the enone 14. Peili Teo of the National University of Singapore devised (Chem. Commun. 2014, 50, 2608) conditions for the Markovnikov hydration of the alkene 6 to the alcohol 15. Internal alkenes were inert under these conditions, but Yoshikazo Kitano of the Tokyo University of Agriculture and Technology effected (Synthesis 2014, 46, 1455) the Markovnikov amination (not illustrated) of more highly substituted alkenes.

scholarly journals Saroj Nalini Arambam Parratt (1933–2008)

2009 ◽  
Vol 19 (3) ◽  
pp. 383-384
Author(s):  
JOHN PARRATT
Keyword(s):  
Field Work ◽  
Eastern Region ◽  
Baptist Church ◽  
Research Fellowship ◽  
Critical Methodology ◽  
North Eastern ◽  
National University ◽  
Princely State ◽  
Extended Field ◽  
The University

Arambam Saroj Nalini was born in Imphal, in the then princely state of Manipur, on June 2nd 1933. Her father was a well-known and respected educationalist and government officer. During the war years he was posted to Jiribam, where she received her first education, and later transferred to a convent school in Haflong. She proceeded to Calcutta University, where she became the first Meetei woman to obtain BA and MA degrees, majoring in Philosophy. While in Calcutta she enjoyed close friendship with Christian Naga students, and converted to Christianity. She was baptised at the Lower Circular Road Baptist church, whose minister, Walter Corlett had himself served in Imphal during the war years. The Christian faith was to become a dominant influence on her future life. She came to Britain in the late 1950s to study theology, and obtained a Bachelor of Divinity degree from London University in 1961. Shortly after she married John Parratt. When their desire to work in India was frustrated they decided to work elsewhere in the developing world, initially in Nigeria, where Saroj became a tutor in philosophy at the University of Ile-Ife. When her husband was offered a research fellowship by the Australian National University she enrolled for a PhD in the Department of Asian Studies there, under the supervision of the eminent indologist A.L.Basham. Despite the frequent absences of her husband on field work in Papua-New Guinea and having to care for three young children, the bulk of the thesis was completed before she returned to Manipur for further extended field work in 1972. The doctorate was awarded three years later, one of her examiners being Professor Suniti Kumar Chatterji, who (unusually for the time) himself had a deep interest in India's north-eastern region. Her thesis was published in 1980 (Firma KLM, Calcutta) as The Religion of Manipur. It marked the beginning of a new phase in writing on Manipur by its rigorous application of critical methodology both in the collection and in the analysis of field data, and had considerable influence on younger Meetei scholars.

Penglibatan Ahli Akademik Terhadap Pengajaran Hadith di Institusi Pengajian

2018 ◽  
pp. 47-52
Author(s):  
Amran Abdul Halim ◽  
Abdulloh Salaeh
Keyword(s):  
Public Universities ◽  
Academic Staff ◽  
Descriptive Analysis ◽  
Good Knowledge ◽  
Islamic Studies ◽  
National University ◽  
Islamic Science ◽  
The University

This study is to identify the involvement of academicians on the teaching of the hadith. The contribution of the academicians to the teaching of the hadith is also very much needed so that Muslims can acknowledge al-Sunnah closely. The academicians were selected from Academic of Islamic Studies, University of Malaya Islamic Studies Academy, the National University of Malaysia, the Islamic Science University of Malaysia and the International Islamic University which they are all from various fields of Islamic Studies. The methodology used in this study is a questionnaire which is group sampling. The researcher distributes the questionnaire to the academic staff at the university involved. Based on this descriptive analysis of the questionnaire, it can be concluded that academic practitioners either in the field of hadith or other fields are involved and contribute to the teaching of hadith such as in public universities and other institutions. This shows that most academicians have good knowledge related to the field of hadith. Therefore, they are among the most suitable as references to the community in solving Sunnah and bidaah issues, especially the academicians who are experts in the field of hadith. Abstrak Kajian ini adalah untuk mengenalpasti penglibatan ahli akademik terhadap pengajaran hadith. Sumbangan ahli akademik terhadap pengajaran hadith juga amat diperlukan agar umat Islam dapat mengenali al-Sunnahsecara  lebih  dekat.  Ahli-ahli  akademik  yang  dipilih  adalah  dari  Akademi  Pengajian  Islam  Universiti Malaya,   Universiti   Kebangsaan   Malaysia,   Universiti   Sains   Islam   Malaysia   dan   Universiti   Islam Antarabangsa  yang  mana  kesemuanya  dalam  pelbagai  bidang  Pengajian  Islam.  Kaedah yang  digunakan dalam kajian ini adalah soal selidik iaitu persampelan berkelompok. Penyelidikmengedarkan borang soal selidik tersebut kepada ahli akademik di universiti tersebut. Berdasarkan, analisis deskriptif soal selidik ini, dapat dirumuskan bahawa ahli akademik sama ada dalam bidang hadith atau lain-lain bidang adalah terlibat dan turut memberi sumbangan dalam pengajaran hadith seperti di universiti-universiti awam dan lain-lain institusi  pengajian.  Ini  menunjukkan  bahawa  kebanyakan  ahli  akademik  mempunyai  pengetahuan  yang baik  berkaitan  dengan  bidang  hadith.  Oleh  itu,  mereka  adalah  antara  golongan  sangat  sesuai  dijadikan sebagai rujukan masyarakat dalam menyelesaikan permasalahan Sunnah dan bidaah, terutama sekali ahli akademik yang pakar dalam bidang hadith.

Factors Influencing Academic Stress on Students of University of Economics and Business - Vietnam National University

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Nham Phong Tuan ◽  
Nguyen Ngoc Quy ◽  
Nguyen Thi Thanh Huyen ◽  
Hong Tra My ◽  
Tran Nhu Phu
Keyword(s):  
Academic Stress ◽  
Stress Factors ◽  
Negative Effects ◽  
Cross Sectional ◽  
Stress Scale ◽  
Perceptions And Attitudes ◽  
National University ◽  
Questionnaire Surveys ◽  
The University ◽  
The Impact

The objective of this study is to investigate the impact of seven factors causing academic stress on students of University of Economics and Business - Vietnam National University: Lack of leisure time, Academic performance, Fear of failure, Academic overload, Finances, Competition between students, Relationships with university faculty. Based on the results of a practical survey of 185 students who are attending any courses at the University of Economics and Business - Vietnam National University, the study assesses the impact of stress factors on students. The thesis focuses on clarifying the concept of "stress" and the stress level of students, while pointing out its negative effects on students. This study includes two cross-sectional questionnaire surveys. The first survey uses a set of 16 questions to assess students’ perceptions and attitudes based on an instrument to measure academic stress - Educational Stress Scale for Adolescents (ESSA). The second survey aims to test internal consistency, the robustness of the previously established 7-factor structure. Henceforth, the model was brought back and used qualitatively, combined with Cronbach’s Alpha measurement test and EFA discovery factor analysis. This study was conducted from October 2019 to December 2019. From these practical analyzes, several proposals were made for the society, the school and the students themselves.

Acceptorless amine dehydrogenation and transamination using Pd-doped layered double hydroxides

2018 ◽  
Author(s):  
Diana Ainembabazi ◽  
Nan An ◽  
Jinesh Manayil ◽  
Kare Wilson ◽  
Adam Lee ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Oxidation States ◽  
Secondary Amines ◽  
Primary Amines ◽  
Acid Dissolution ◽  
Oxidative Amination ◽  
Strong Function ◽  
Excellent Activity ◽  
High Yields ◽  
Double Hydroxides

<div> <p>The synthesis, characterization, and activity of Pd-doped layered double hydroxides (Pd-LDHs) for for acceptorless amine dehydrogenation is reported. These multifunctional catalysts comprise Brønsted basic and Lewis acidic surface sites that stabilize Pd species in 0, 2+, and 4+ oxidation states. Pd speciation and corresponding cataytic performance is a strong function of metal loading. Excellent activity is observed for the oxidative transamination of primary amines and acceptorless dehydrogenation of secondary amines to secondary imines using a low Pd loading (0.5 mol%), without the need for oxidants. N-heterocycles, such as indoline, 1,2,3,4-tetrahydroquinoline, and piperidine, are dehydrogenated to the corresponding aromatics with high yields. The relative yields of secondary imines are proportional to the calculated free energy of reaction, while yields for oxidative amination correlate with the electrophilicity of primary imine intermediates. Reversible amine dehydrogenation and imine hydrogenation determine the relative imine:amine selectivity. Poisoning tests evidence that Pd-LDHs operate heterogeneously, with negligible metal leaching; catalysts can be regenerated by acid dissolution and re-precipitation.</p> </div> <br>

Chernivtsi National University during the Romanian period in Bukovina’s history (1918-1940)

2017 ◽  
pp. 118-125
Author(s):  
Liubov Melnychuk
Keyword(s):  
Higher Education ◽  
Church And State ◽  
Radical Change ◽  
The State ◽  
Ongoing Training ◽  
State Apparatus ◽  
National University ◽  
The Government ◽  
The University

The author investigates and analyzes the state Chernivtsi National University during the Romanian period in Bukovina’s history. During that period in the field of education was held a radical change in the direction of intensive Romanization. In period of rigid occupation regime in the province, the government of Romania laid its hopes on the University. The Chernivtsi National University had become a hotbed of Romanization ideas, to ongoing training for church and state apparatus, to educate students in the spirit of devotion Romania. Keywords: Chernivtsi National University, Romania, Romanization, higher education, Bukovina

scholarly journals Metal-Free Air Oxidation in a Convenient Cascade Approach for the Access to Isoquinoline-1,3,4(2H)-triones

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2177
Author(s):  
Antonia Di Mola ◽  
Consiglia Tedesco ◽  
Antonio Massa
Keyword(s):  
Heterocyclic Compounds ◽  
Aromatic Ketone ◽  
Primary Amines ◽  
Cascade Process ◽  
Staudinger Reaction ◽  
Caspase Inhibitor ◽  
Air Oxidation ◽  
Metal Free ◽  
Free Air

Herein we describe a very useful application of the readily available trifunctional aromatic ketone methyl-2-(2-bromoacetyl)benzoate in reactions with primary amines. An unexpected in situ air oxidation that follows a cascade process allowed the access to a series of isoquinoline-1,3,4(2H)-triones, a class of heterocyclic compounds of great interest containing an oxygen-rich heterocyclic scaffold. A modification of the original protocol, utilizing a Staudinger reaction in the presence of trimethylphosphine, was necessary for the synthesis of Caspase inhibitor trione with free NH group.

Cyclic amidines derived from benz[c,d]indole and 4,5-dihydro-3H-1-benzazepine including some related compounds: Synthesis and pharmacological screening

1985 ◽  
Vol 50 (8) ◽  
pp. 1888-1898 ◽  
Author(s):  
Miroslav Protiva ◽  
Zdeněk Šedivý ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
Jiří Němec
Keyword(s):  
Titanium Tetrachloride ◽  
Aqueous Sodium Hydroxide ◽  
Secondary Amines ◽  
Primary Amines ◽  
Open Chain ◽  
Lithium Aluminium ◽  
Pharmacological Screening ◽  
Antiinflammatory Effects ◽  
Related Compounds ◽  
Sodium Amide

Reactions of naphthostyril (I) with primary and secondary amines and titanium tetrachloride afforded cyclic amidines III-IX. Hydrogenation of I on Pd-C resulted in the 6,7,8,8a-tetrahydro derivative X which gave by treatment with sodium amide and 3-dimethylaminopropyl chloride the N-(aminoalkyl) compound XI. Reduction of I and its N-methyl derivative II with sodium amalgam in aqueous sodium hydroxide gave the 2a,3,4,5-tetrahydro derivatives XII and XIII. Reaction of XIII with sodium amide and 3-dimethylaminopropyl chloride afforded the 2a-(aminoalkyl) compound XIV. 1,3,4,5-Tetrahydro-1-benzazepin-2-one (XV) treated with primary amines and titanium tetrachloride gave the amidines XVI-XVIII. 3-Methyl-7,8,9,9a-tetrahydro-1H-benz[d,e]isoquinoline (XIX) was reduced with sodium borohydride to compound XX which was alkylated with propargyl bromide to 1-methyl-2-propargyl-2,3,3a,4,5,6-hexahydro-1H-benz[d,e]isoquinoline (XXI). An attempt to prepare the 2-(2-phenylethyl) analogue by treatment of compound XX with phenylacetyl chloride and by the following reduction with lithium aluminium hydride resulted in the open-chain amine XXII. The lactams I, II, X, and XIII showed some discoordinating, hypothermic, peripheral vasodilating, hyperglycaemic, diuretic and antiinflammatory effects. The amidines III-IX and XVI-XVIII had local anaesthetic, slight hypotensive, antiarrhythmic, peripheral myorelaxant, papaverine-like spasmolytic and thiopental potentiating effects.

Sign in / Sign up

Export Citation Format

Share Document