Variable coordination of amine functionalised N-heterocyclic carbene ligands to Ru, Rh and Rr: C-H and N-H activation and catalytic transfer hydrogenation

Chelating amine and amido complexes of late transition metals are highly valuable bifunctional catalysts in organic synthesis, but complexes of bidentate amine–NHC and amido–NHC ligands are scarce. Hence, we report the reactions of a secondary-amine functionalised imidazolium salt 2a and a primary-amine functionalised imidazolium salt 2b with [( p -cymene)RuCl 2 ] 2 and [Cp*MCl 2 ] 2 (M = Rh, Ir). Treating 2a with [Cp*MCl 2 ] 2 and NaOAc gave the cyclometallated compounds Cp*M(C,C)I (M = Rh, 3 ;M = Ir, 4 ), resulting from aromatic C–H activation. In contrast, treating 2b with [( p -cymene)RuCl 2 ] 2 ,Ag 2 O and KI gave the amine–NHC complex [( p -cymene)Ru(C,NH 2 )I]I ( 5 ). The reaction of 2b with [Cp*MCl 2 ] 2 (M = Rh, Ir), NaO t Bu and KI gave the amine–NHC complex [Cp*Rh(NH 2 )I]I ( 6 ) or the amido–NHC complex Cp*Ir(C,NH)I ( 7 ); both protonation states of the Ir complex could be accessed: treating 7 with trifluoroacetic acid gave the amine–NHC complex [Cp*Ir(C,NH 2 )I][CF 3 CO 2 ]( 8 ). These are the first primary amine– or amido–NHC complexes of Rh and Ir. Solid-state structures of the complexes 3–8 have been determined by single crystal X-ray diffraction. Complexes 5 , 6 and 7 are pre-catalysts for the catalytic transfer hydrogenation of acetophenone to 1-phenylethanol, with ruthenium complex 5 demonstrating especially high reactivity

Ir(III) complexes of diamine ligands for asymmetric ketone hydrogenation

The use of a combination of IrCl3 with a series of ligands derived from the C2-symmetric diamine diphenylethanediamine (DPEN) forms a catalyst capable of the asymmetric hydrogenation of ketones in up to 85% ee

Use of tridentate TsDPEN/pyridine ligands in ruthenium-catalysed asymmetric reduction of ketones

A series of enantiomerically pure tridentate ligands based on the 1,2-diphenylethane-1,2-diamine structure, containing additional pyridine groups, was prepared and tested in asymmetric transfer hydrogenation of ketones using Ru3(CO)12 as a metal source. Alcohols were formed in up to 93% ee in the best cases, and good results were obtained with ortho-haloarylketones

Synthesis and asymmetric hydrogenation of (3E)-1-benzyl-3-[(2-oxopyridin-1(2H)-yl)methylidene]piperidine-2,6-dione

The synthesis of (3E)-1-benzyl-3-[(2-oxopyridin-1(2H)-yl)methylidene]piperidine-2,6-dione 4 from N-benzylglutarimide was achieved in three steps. The asymmetric hydrogenation of 4 gave either the product of partial reduction (10) or full reduction (13), depending on the catalyst which was employed, in high ee in each case. Attempts at asymmetric transfer hydrogenation (ATH) of 4 resulted in formation of a racemic product

Ruthenacycles and Iridacycles as Catalysts for Asymmetric Transfer Hydrogenation and Racemisation

Ruthenacycles, which are easily prepared in a single step by reaction between enantiopure aromatic amines and [Ru(arene)Cl2]2 in the presence of NaOH and KPF6, are very good asymmetric transfer hydrogenation catalysts. A range of aromatic ketones were reduced using isopropanol in good yields with ee’s up to 98%. Iridacycles, which are prepared in similar fashion from [IrCp*Cl2]2 are excellent catalysts for the racemisation of secondary alcohols and chlorohydrins at room temperature. This allowed the development of a new dynamic kinetic resolution of chlorohydrins to the enantiopure epoxides in up to 90% yield and 98% enantiomeric excess (ee) using a mutant of the enzyme Haloalcohol dehalogenase C and an iridacycle as racemisation catalyst.

Synthesis and asymmetric hydrogenation of (3E)-1-benzyl-3-[(2-oxopyridin-1(2H)-yl)methylidene]piperidine-2,6-dione

The synthesis of (3E)-1-benzyl-3-[(2-oxopyridin-1(2H)-yl)methylidene]piperidine-2,6-dione 4 from N-benzylglutarimide was achieved in three steps. The asymmetric hydrogenation of 4 gave either the product of partial reduction (10) or full reduction (13), depending on the catalyst which was employed, in high ee in each case. Attempts at asymmetric transfer hydrogenation (ATH) of 4 resulted in formation of a racemic product

Проблема конкуренції криінально-правових норм (кримінальних законів) у науці пострадянського (радянського) кримінального права та в науці кримінального права держав, які відносяться до романо-германської правової сім'ї

У статті проаналізовано наукові погляди на конкуренцію кримінально-правових норм (кримінальних законів) у теорії пострадянського (радянського) кримінального права та в теорії кримінального права держав, які відносяться до романо-германської правової сім'ї. Ключові слова: конкуренція кримінально-правових норм, конкуренція законів.В статье анализируются научные взгляды на конкуренцию уголовно-правовых норм (уголовных законов) в теории постсоветского (советского) уголовного права и в теории уголовного права государств, которые относятся к романо-германской правовой семье. Ключевые слова: конкуренция уголовно-правовых норм, конкуренция законов.In the article scientific looks are analyzed to the competition of criminal law norm’s (criminal laws) in the theory of post-soviet (soviet) criminal law and in the theory of criminal law of the states which behave to the legal system of civil law. Key words: competition of criminal law norm’s, competition of laws

Exploring EFL Students' Strategies in Writing Research Background at One of the Universities in Cirebon

Learning strategies assist students in revealing their individual learning style, recognizing their identity as “learners”, and being conscious of their learning obstacles. The current study aimed to investigate the strategies in writing research background encountered by English Department students at one of Cirebon’s institutions throughout the academic year 2021/2022. This study employed a qualitative technique with a case study design, with thirty students participating as respondents. The data was gathered via a questionnaire and an interview. There are two research instruments in this research, especially close-ended questionnaire and semi-structured interview.The instruments were also distributed in Bahasa Indonesia. According to the findings, students adopted strategies such as reviewing the references of journal articles. This causes students to use strategies to reduce these difficulties, including reading reference journals or articles. The score using this strategy is 95%.  Furthermore, respondents indicated that they were requesting revisions from their supervisor.This is the experience of lecturers were better because they have done research many times. As a result, they were changing the sentence structure check.In addition, it creates sentences that are difficult to understand between sentences and paragraphs that are out of sync. There was a need for a revision of the review to produce a coherent reading and not confused the readers.It is suggested that the students choose the appropriate strategy, so that the strategy can be implemented properly

PENINGKATAN HASIL BELAJAR IPAS PADA MATERI SISTEM PERNAPASAN MANUSIA MELALUI MEDIA PEMBELAJARAN ASPERA DI KELAS V SDN SUNYARAGI 1

This study aims to analyze the improvement of students' learning outcomes on the topic of the human respiratory system through the use of the ASPERA learning media (Teaching Aids for the Human Respiratory System). The method used is Classroom Action Research (CAR) following the spiral model of C. Kemmis and McTaggart, conducted in two cycles. The research subjects were 27 fifth-grade students of SDN Sunyaragi 1. The data collection technique employed was testing, with test items as the research instrument. Data analysis was carried out both qualitatively and quantitatively using descriptive statistics based on the average scores and mastery learning of the IPAS (Science) subject on the human respiratory system topic. The results showed that in the pre-cycle, the average student score was 64.81, categorized as fair, with a learning mastery percentage of 56%. In Cycle I, the average score increased to 75.19, categorized as good, with a mastery percentage of 74%. Since Cycle I did not meet the success indicator of 85%, the researcher conducted reflection and improvement in Cycle II. In Cycle II, the average student score reached 84.07, categorized as very good, with a mastery percentage of 100%. Thus, the use of the ASPERA learning media (Teaching Aids for the Human Respiratory System) is effective in improving students' learning outcomes on the topic of the human respiratory system in Grade V