- Asymmetric catalysis with a chiral-at-osmium complex
-
The first example of a chiral osmium catalyst is reported in which the overall chirality originates exclusively from a stereogenic metal center (metal-centered chirality) with all coordinating ligands being achiral. The non-C2-symmetric chiral-at-metal complex contains two cyclometalated 7-methyl-1,7-phenanthrolinium heterocycles which can be described as two chelating pyridylidene remote N-heterocyclic carbene (rNHC) ligands. The octahedral coordination sphere is completed with one CO and one acetonitrile ligand. A monodentate chiral oxazoline ligand is used as a chiral auxiliary ligand to obtain enantiomerically pure chiral-at-osmium complexes (>99?:?1 e.r.). Finally, it is demonstrated that the developed chiral-at-osmium complex is suitable for ring-closing enantioselective C(sp3)-H aminations, including the first example of catalytic enantioselective cyclizations of azidoformates to chiral 2-oxazolidinones.
- Wang, Guanghui,Zhou, Zijun,Shen, Xiang,Ivlev, Sergei,Meggers, Eric
-
supporting information
p. 7714 - 7717
(2020/07/27)
-
- Enantioselective Radical Construction of 5-Membered Cyclic Sulfonamides by Metalloradical C-H Amination
-
Both arylsulfonyl and alkylsulfonyl azides can be effectively activated by the cobalt(II) complexes of D2-symmetric chiral amidoporphyrins for enantioselective radical 1,5-C-H amination to stereoselectively construct 5-membered cyclic sulfonami
- Hu, Yang,Lang, Kai,Li, Chaoqun,Gill, Joseph B.,Kim, Isaac,Lu, Hongjian,Fields, Kimberly B.,Marshall, McKenzie,Cheng, Qigan,Cui, Xin,Wojtas, Lukasz,Zhang, X. Peter
-
supporting information
p. 18160 - 18169
(2019/11/19)
-
- Microwave-assisted synthesis of sodium sulfonates precursors of sulfonyl chlorides and fluorides
-
We describe the use of a microwave reaction for the conversion of various bromides to sodium sulfonates that have been further elaborated to sulfonyl chlorides. This new approach leads to much improved yields and shorter reaction times. Representative sul
- Alapafuja, Shakiru O.,Nikas, Spyros P.,Shukla, Vidyanand G.,Papanastasiou, Ioannis,Makriyannis, Alexandros
-
experimental part
p. 7028 - 7031
(2010/02/28)
-
- Arylalkane-sulfonamides having endothelin-antagonist activity
-
The invention relates to novel aryl-alkane-sulfonamides and their use as active ingredients in the preparation of pharmaceutical compositions. The invention also concerns related aspects including processes for the preparation of the compounds, pharmaceutical compositions containing one or more of those compounds and especially their use as endothelin receptor antagonists.
- -
-
-
- N-Sulfonyl homoserine lactones as antagonists of bacterial quorum sensing
-
A series of 11 N-sulfonyl homoserine lactones has been synthesised. Some of them were found to competitively inhibit the action of 3-oxohexanoyl-L- homoserine lactone, the natural inducer of bioluminescence in the bacterium Vibrio fischeri. Molecular modeling suggests a possible explanation based on the prevention of structural rearrangements necessary for the formation of the active dimer of LuxR.
- Castang, Sandra,Chantegrel, Bernard,Deshayes, Christian,Dolmazon, René,Gouet, Patrice,Haser, Richard,Reverchon, Sylvie,Nasser, William,Hugouvieux-Cotte-Pattat, Nicole,Doutheau, Alain
-
p. 5145 - 5149
(2007/10/03)
-
- COMPOUNDS AND METHODS FOR CONTROLLING BACTERIAL VIRULENCE
-
Novel sulfonated homoserine lactones formula I have been found to act ac quorum sensing inhibitors. As such, they may be useful in the treatment of bacterial infections.
- -
-
-
- Solution and Flash Vacuum Pyrolyses of 3-Arylpropanesulfonyl and 2-(Aryloxy)ethanesulfonyl Azides. Synthesis of 7-Membered Sultams
-
The solution and flash vacuum pyrolyses of 3-arylpropanesulfonyl azides have been studied and the results compared with those of the corresponding 2-arylethanesulfonyl azides.The best yields of 7-membered ring sultams are formed on solution decomposition in Freon 113.Hydrogen abstraction and solvent insertion products are obtained mainly in hydrocarbon solvents.The structure of the 7-membered sultams have been established unambiguously and an authentic sample of the parent 2,3,4,5-tetrahydro-1,2-thiazepine 1,1-dioxide prepared.Decomposition of 3-(2,6-dichlorophenyl)propanesulfonyl azide (22) leads to a 6,9-dichloro sultam (33c) via a 1,2-chlorine shift.FVP of 3-(2-mesityl)propanesulfonyl azide (20) gave a good yield of the 7-membered ring sultam (34)(1,2-methyl shift).FVP of 3-phenyl-1-propanesulfonyl azide (16) at 995 deg C (0.05 mm) gave, among other products, a 6.2percent yield of 5,6,7,8-tetrahydroquinoline (39).The formation of these products is discussed.Thermolysis of 2-(aryloxy)ethanesulfonyl azides gave the corresponding 7-membered ring sultams 27 as well.
- Abramovitch, Rudolph A.,Kress, Albert O.,McManus, Samuel P.,Smith, Maurice R.
-
p. 3114 - 3121
(2007/10/02)
-
- Synthesis of Alkanesulphonyl Chlorides from Alkylcobaloximes and Trichloromethanesulphonyl Chloride
-
Alkyl- and substituted alkylcobaloximes react photochemically with trichloromethanesulphonyl chloride to give high yields of alkanesulphonyl chlorides. erythro-2-Phenylethylcobaloxime gives an equimolar mixture of erythro- and threo-2-phenylethanesulphonyl chloride and diastereoisomerically pure 1-phenylpropan-2-ylcobaloxime gives a 1:1 mixture of diastereoisomers of 1-phenylpropane-2-sulphonyl chloride.The reaction is believed to proceed through a non-chain process initiated by photolysis of the carbon-cobalt bond.The product alkanesulphonyl chloride is then formed, either by a direct attack of the alkyl radical on the sulphur of trichloromethanesulphonyl chloride, or through capture of the alkyl radical by sulphur dioxide and halogen abstraction by the so-formed alkanesulphonyl radical from trichloromethanesulphonyl chloride.The latter process seems the more likely.No evidence could be obtained for an intermolecular homolytic attack of trichloromethyl radicals on the saturated alkyl ligand.
- Bougeard, Peter,Johnson, Michael D.,Lampman, Gary M.
-
p. 849 - 854
(2007/10/02)
-
