نتایج جستجو برای: substituted

تعداد نتایج: 39156  

2009
Reinhold Zimmer Elmar Schmidt Michal Andrä Marcel-Antoine Duhs Igor Linder Hans-Ulrich Reissig

A number of 4-aryl- and 4-alkynyl-substituted 6H-1,2-oxazines 8 and 9 have been prepared in good yields via cross coupling reactions of halogenated precursors 2, which in turn are easily accessible by bromination of 6H-1,2-oxazines 1. Lewis-acid promoted reaction of 1,2-oxazine 9c with 1-hexyne provided alkynyl-substituted pyridine derivative 12 thus demonstrating the potential of this approach...

Journal: :Chemical communications 2012
Yuh Kohyama Takashi Murase Makoto Fujita

Aryl-substituted allylic chlorides are accommodated by a self-assembled cage in such a restricted orientation that the internal reaction sites are shielded while the external ones are exposed. This non-covalent protection enhances terminal regioselectivity in the allylic substitution.

Journal: :Organic & biomolecular chemistry 2016
Naohiko Ikuma Koji Nakagawa Ken Kokubo Takumi Oshima

Grignard reagents (RMgBr: R = Et, p-tolyl) selectively attacked the β-position of the bridgehead double bond of tosylazafulleroid through interaction of Mg with the S[double bond, length as m-dash]O group. The following [5,6] ring closure and C-N bond scission led to aryl/alkyl aminylfullerenes with 1,2-configuration. Tolyl-substituted aminylfullerene was further converted into 1,4-di(p-tolyl)f...

2016
Barbora Hanulikova Ivo Kuritka Pavel Urbanek

BACKGROUND Recent efforts in the field of mesoscale effects on the structure and properties of thin polymer films call to revival interest in conformational structure and defects of a polymer backbone which has a crucial influence on electronic properties of the material. Oligo[methyl(phenyl)silylene]s (OMPSi) as exemplary molecules were studied theoretically by DFT in the form of optimal decam...

2014
Andreas Gansäuer Andreas Okkel Lukas Schwach Laura Wagner Anja Selig Aram Prokop

An operationally simple, convenient, and mild strategy for the synthesis of triazole-substituted titanocenes via strain-driven 1,3-dipolar cycloadditions between azide-functionalized titanocenes and cyclooctyne has been developed. It features the first synthesis of titanocenes containing azide groups. These compounds constitute 'second-generation' functionalized titanocene building blocks for f...

Journal: :Journal of nematology 1988
R D Riggs D P Schmitt G R Noel

Tests of Heterodera glycines on differential host plants to determine races were run in Arkansas, Illinois, and North Carolina to check the uniformity of results of the test. Methods used at the three locations varied somewhat. Results indicate that the race test is highly variable. Isolates previously identified as race 1 were identified as race 1 or race 3; those identified as race 2 were ide...

Journal: :Chemical communications 2014
Victor Gray Anders Lennartson Phasin Ratanalert Karl Börjesson Kasper Moth-Poulsen

Red-shifting the absorption of norbornadienes (NBDs), into the visible region, enables the photo-isomerization of NBDs to quadricyclanes (QCs) to be driven by sunlight. This is necessary in order to utilize the NBD-QC system for molecular solar thermal (MOST) energy storage. Reported here is a study on five diaryl-substituted norbornadienes. The introduced aryl-groups induce a significant red-s...

Journal: :Journal of nematology 1977
R D Riggs M L Hamblen L Rakes

The reproductive abilities of four races of Heterodera glycines were compared on soybean cultivars by using single cyst or mass inoculations. Progeny transfers were used to determine changes in reproduction of H. glycines. Reproduction of all races (1, 2, 3, 4) was best on 'Lee' and poorest on P1 88788. The size of females produced and numbers of eggs/female of the different races varied with t...

2010
Tilman Lechel Irene Brüdgam Hans-Ulrich Reissig

A series of trifluoromethyl-substituted 3-alkoxypyridinol derivatives has been deprotected to furnish pyridine-3,4-diol derivatives in good yields. The X-ray crystal structure analysis proved that a 1:1 mixture of pyridine-3,4-diols and their pyridin-4-one tautomers exist in the solid state. Subsequent conversion into bis(perfluoroalkanesulfonate)s were smoothly achieved. The obtained compounds...

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