TY  - JOUR
A1  - Gessner, Viktoria H.
T1  - Diphenyl[2-(phenyl-sulfon-yl)propan-2-yl]-\(\lambda^5\)-phosphanethione
JF  - Acta crystallographica. Section E, Structure reports online
N2  - The title compound, \(C_{21}H_{21}O_2PS_2\), was obtained from the corresponding dilithio methandiide by treatment with iodo-methane. The bond lengths and angles deviate considerably from those in the dimetallated compound. These differences are most pronounced in the PCS backbone. While the title compound features C-P and C-S distances of 1.9082(17) and 1.8348(17)Å, respectively, the dianion showed \(C-P_{av}\) distances shortened by 11% [1.710(4)Å] and C-S distances shortened by 12% [1.614(3)Å]. Additionally, the P-C-S angle experiences a contraction by methyl-ation of the dianion from 121.4(2) to 111.96(9)° in the title compound.
KW  - wR factor = 0.068
KW  - mean σ(C–C) = 0.003 Å
KW  - T = 173 K
KW  - single-crystal X-ray study
KW  - R factor = 0.025
KW  - data-to-parameter ratio = 14.6
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123635
VL  - E68
IS  - o1045
ER  - 
TY  - JOUR
A1  - Hartung, Andreas
A1  - Seufert, Florian
A1  - Berges, Carsten
A1  - Gessner, Viktoria H.
A1  - Holzgrabe, Ulrike
T1  - One-Pot Ugi/Aza-Michael Synthesis of Highly Substituted 2,5-Diketopiperazines with Anti-Proliferative Properties
JF  - Molecules
N2  - The well-known Ugi reaction of aldehydes with amines, carboxylic acids and isocyanides leads to the formation of acyclic alpha-acylaminocarboxamides. Replacement of the carboxylic acid derivatives with beta-acyl substituted acrylic acids gives access to highly substituted 2,5-diketopiperazines in one single reaction-step without additives or complex reaction procedures. The obtained diketopiperazines show anti-proliferative effects on activated T cells and represent therefore potential candidates for targeting unwanted T cell-mediated immune responses.
KW  - multicomponent Ugi-type reaction
KW  - intramolecular Michael addition
KW  - strategy
KW  - derivates
KW  - diketopiperazines
KW  - chemistry
KW  - T cell
KW  - 2,5-diketopiperazines
KW  - anti-proliferative effects
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130423
VL  - 17
IS  - 12
ER  - 
TY  - JOUR
A1  - Gessner, Viktoria H.
T1  - Diphenyl[(phenylsulfanyl)methyl]-\(λ^5\)-phosphanethione
JF  - Acta Crystallographica, Section E: Structure Reports
N2  - The title compound, \(C_{19}H_{17}PS_2\), results from the direct deprotonation of di­phenyl­methyl­phosphine sulfide and subsequent reaction with diphenyl di­sulfide. The C-P and C-S bond lengths of 1.8242 (18) and 1.8009 (18) Å, respectively, of the central P-C-S linkage are comparable to those found in the sulfonyl analogue, but are considerably longer than those reported for the dimetallated sulfonyl compound. The dihedral angle between the benzene rings of the di­phenyl­methyl moiety is 69.46 (7)°. No distinct inter­molecular inter­actions are present in the crystal structure.
KW  - crystal structure
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120174
VL  - 70
IS  - 3
ER  - 
TY  - JOUR
A1  - Scherpf, Thorsten
A1  - Schwarz, Christopher
A1  - Scharf, Lennart T.
A1  - Zur, Jana-Alina
A1  - Helbig, Andeas
A1  - Gessner, Viktoria H.
T1  - Ylide-Functionalized Phosphines: Strong Donor Ligands for Homogeneous Catalysis
JF  - Angewandte Chemie - International Edition
N2  - Phosphines are important ligands in homogenous catalysis and have been crucial for many advances, such as in cross-coupling, hydrofunctionalization, or hydrogenation reactions. Herein we report the synthesis and application of a novel class of phosphines bearing ylide substituents. These phosphines are easily accessible via different synthetic routes from commercially available starting materials. Owing to the extra donation from the ylide group to the phosphorus center the ligands are unusually electron-rich and can thus function as strong electron donors. The donor capacity surpasses that of commonly used phosphines and carbenes and can easily be tuned by changing the substitution pattern at the ylidic carbon atom. The huge potential of ylide-functionalized phosphines in catalysis is demonstrated by their use in gold catalysis. Excellent performance at low catalyst loadings under mild reaction conditions is thus seen in different types of transformations.
KW  - carbanion
KW  - homogeneous catalysis
KW  - phosphine ligands
KW  - structure elucidation
KW  - ylides
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-228551
VL  - 57
IS  - 39
ER  -