TY  - JOUR
A1  - Wessig, Pablo
A1  - Krebs, Saskia
T1  - N-aroylsulfonamide-photofragmentation (ASAP)
BT  - a versatile route to biaryls
JF  - European journal of organic chemistry
N2  - The photochemical fragmentation of N-aroylsulfonamides 9 (ASAP) is a powerful method for the preparation of various biaryls. Compounds 9 are easily accessible in two steps from amines by treatment with arenesulfonyl chlorides and aroyl chlorides. Many of these compounds were prepared for the first time. The irradiation takes place in a previously developed continuous-flow reactor using inexpensive UVB or UVC fluorescent lamps. Isocyanates and sulphur dioxide are formed as the only by-products. The ASAP tolerates a variety of functional groups and is even suited for the preparation of phenylnaphthalenes and terphenyls. The ASAP mechanism was elucidated by interaction of photophysical and quantum chemical (DFT) methods and revealed a spirocyclic biradical as key intermediate.
KW  - Biaryls
KW  - Fragmentation
KW  - Isocyanates
KW  - Photochemistry
KW  - Sulfonamides
Y1  - 2021
U6  - https://doi.org/10.1002/ejoc.202100955
SN  - 1434-193X
SN  - 1099-0690
VL  - 2021
IS  - 46
SP  - 6367
EP  - 6374
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Sand, Patrick
A1  - Schmidt, Bernd
T1  - Ruthenium-catalyzed sulfoalkenylation of acetanilides and dual-use of the catalyst directing group
JF  - European journal of organic chemistry
N2  - In contrast to vinylsulfonates and vinylsulfones, vinylsulfonamides are unreactive in Pd-catalyzed oxidative Heck-coupling reactions with acetanilides. This limitation has been resolved by using a C-H-activation protocol based on Ru-Cu-Ag-catalysis. Overall, the Ru-Cu-Ag-catalyzed conditions turned out to be more reliable and showed better reproducibility than the Pd-catalyzed C-H-activation. The coupling products thus obtained are functionalized styrenyl sulfones and -sulfonamides which can be used as starting materials for the synthesis of sulfonyl pyrroles and sulfonyl pyrrolo[2,3-c]quinolines.
KW  - Arenes
KW  - C-H activation
KW  - Heterocycles
KW  - Ruthenium
KW  - Sulfonamides
Y1  - 2021
U6  - https://doi.org/10.1002/ejoc.202101216
SN  - 1434-193X
SN  - 1099-0690
VL  - 2021
IS  - 40
SP  - 5497
EP  - 5506
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schmidt, Bernd
A1  - Wolf, Felix
A1  - Brunner, Heiko
T1  - Styrylsulfonates and -Sulfonamides through Pd-Catalysed Matsuda-Heck Reactions of Vinylsulfonic Acid Derivatives and Arenediazonium Salts
JF  - European journal of organic chemistry
N2  - Arene diazonium salts undergo Matsuda-Heck reactions with vinylsulfonates and -sulfonamides to give styrylsulfonic acid derivatives in high to excellent yields and with high to excellent selectivities. By quantifying the evolution of nitrogen over time in a gas-meter apparatus, the reactivities of ethylvinylsulfonate and the benchmark olefin methyl acrylate were compared for an electron-rich and an -deficient arene diazonium salt. Tertiary sulfonamides react in Matsuda-Heck couplings with high conversions, but require long reaction times, which prevents the determination of kinetic data through the measurement of nitrogen evolution. Secondary sulfonamides were found to be unreactive. From these results, the following order of reactivity could be deduced: H2C=CHCO2Me > H2C=CHSO2OEt > H2C=CHSO2N(Me)Bn >> H2C=CHSO2NHBn. Through the Matsuda-Heck coupling of 5-indolyldiazonium salt and a tertiary vinylsulfonamide, the synthesis of the C-5-substituted indole part of the antimigraine drug naratriptan was accomplished in high yield.
KW  - Homogeneous catalysis
KW  - Cross-coupling
KW  - Palladium
KW  - Sulfonamides
KW  - Alkenes
KW  - Drug design
Y1  - 2016
U6  - https://doi.org/10.1002/ejoc.201600469
SN  - 1434-193X
SN  - 1099-0690
SP  - 2972
EP  - 2982
PB  - Wiley-VCH
CY  - Weinheim
ER  -