Исследование характеристик пробоя твердых горючих ископаемых при воздействии джоулева тепла и частичных разрядов

Актуальность темы: оценка целесообразности применения электрофизического способа конверсии твердых горючих ископаемых. Объект исследования является тепловой и триинговый пробой в горючих сланцах. Пробой как способ формирования нагревательного элемента в толще пласта, для дальнейшей термической конверсии органических компонентов породы. Цель исследовательской работы: экспериментальное определение влияния времени воздействия частичных разрядов и джоулева тепла на напряжение и механизм пробоя. В ходе исследования была проведена серия опытов по пробою горючего сланца, выявлены зависимости характеризующие тепловой и триинговый пробой.Relevance of the topic: evaluation of the expediency of using the electro- physical method of conversion of solid fossil fuels. Object of a research is thermal and treeing breakdown in oil shales. Thermal breakdown as a method of forming a heating element in the shale formation, for further thermal conversion of organic formation components. Aim of the study is the experimental determination of the partial discharges action time influence and Joule heat influence on the voltage and the mechanism of breakdown. During the course of study, a series of experiments on the breakdown of oil shale was conducted, and dependences characterizing the thermal and triage breakdown were revealed

Organokatalytische Chromanonsynthese und enantioselektive Synthese von Isochromanonen und polysubstituierten Cyclohexanderivaten

In this work a new organocatalytic variation for a Friedel-Crafts-type reaction of indoles with chromanones and a cyclopropanation of chromanones has been developed. Moreover, it was developed an enantioselective organocatalytic one-pot reaction of polysubstituted cyclohexanecarbaldehydes with six stereocenters from three different components. It was also possible to synthesize isochromanonderivatives by an organocatalytic procedure and thus to create an access for the synthesis of natural products. The best results for the cyclopropanation of chromanones (1) were achieved with sparteine and potassium carbonate. By varying the reaction conditions and the processing method the yield can be increased to 77% and a dr of 78:22 by using K2CO3 (Fig. 1). It was successfully performed a Friedel-Crafts-type reaction of indoles 6 and 3-nitro-chromanones 4. For this reaction was used N,N'-dimethylthiourea (5) (Fig. 2). A chiral catalyst 8 was also successfully used in this reaction (Fig. 3). The problem was the measurement of the enantiomeric excess because the products decompose on the HPLC. Also using chiral auxiliary reagents within an NMR measurement the enantiomeric excess could not be determined. Using 10 mol% of the catalyst 8 it was obtained a dr greater than 95:5 and it was measured a rotation value of -12.8 degrees. This result proves an enantiomeric excess in this reaction. It was developed an asymmetric organocatalytic one-pot reaction, which can be handled very flexible and simple. By means of this one-pot reaction sequence could easily be synthesized highly substituted cyclohexanecarbaldehydes 13 with six stereocenters (Fig. 4). The resulting cyclohexanes wear many functional groups such as a hydroxygroup, an ester, and a nitrogroup, which make further reactions possible. The first step of this one-pot reaction, the Michael addition, was initiated by the bifunctional thioureacatalyst 12. Followed by the amine-catalyzed Michael / aldol addition by means of an iminium / enamine activation were obtained good yields (22-70%) by generating three new bonds and six stereocenters. On this way excellent diastereoselectivities of >95:5 and enantioselectivities 91-98% were obtained. It could be demonstrated a simple organocatalytic access for isochromanones 16. This takes place by means of proline as catalyst by an intramolecular aldol addition. The standard system, the 2-carboxybenzaldehyde-2-oxopropylester, was obtained in quantitative yield with a diastereoselectivity of 5:1 and an enantiomeric excess 82% (Fig. 5). After recrystallization only one diastereomer with an enantiomeric excess of 90% was obtained. Furthermore, it was already possible to use some varied substrates, but they were not converted with the same success as the standard system. All other examples were either in yield or the stereoselectivity less successful. This should be improved in future studies