- Efficient visible-light photocatalytic aerobic oxidation of cyclic sulfamides to imines
-
A highly efficient photocatalytic aerobic oxidation of cyclic sulfamides to synthesize cyclic N-sulfonyl imines with Ir(ppy)2(dtbpy)PF6 as photocatalyst is reported. These environmentally friendly transformations exihibit good to excellent isolated yields and good generality with respect to both five-membered and six-membered cyclic sulfamides.
- Ming, Zong-Yao,Li, Kang-Rui,Meng, Fan-Jie,Shi, Lei,Jiang, Wen-Feng
-
supporting information
(2020/06/17)
-
- Nitrene transfer catalyzed by a non-heme iron enzyme and enhanced by non-native small-molecule ligands
-
Transition-metal catalysis is a powerful tool for the construction of chemical bonds. Here we show that Pseudomonas savastanoi ethylene-forming enzyme, a non-heme iron enzyme, can catalyze olefin aziridination and nitrene C-H insertion, and that these activities can be improved by directed evolution. The non-heme iron center allows for facile modification of the primary coordination sphere by addition of metal-coordinating molecules, enabling control over enzyme activity and selectivity using small molecules.
- Goldberg, Nathaniel W.,Knight, Anders M.,Zhang, Ruijie K.,Arnold, Frances H.
-
supporting information
p. 19585 - 19588
(2019/12/24)
-
- Sultam compound and preparation method thereof
-
The invention provides a sultam compound and a preparation method thereof. The method provided by the invention specifically comprises the following steps: putting a catalyst C, sulfamide B and an oxidant D into an organic solvent, performing a reaction,
- -
-
Paragraph 0054-0057; 0105-0107
(2019/11/12)
-
- B(C6F5)3-Catalyzed Reduction of Cyclic N-Sulfonyl Ketimines
-
A metal-free method for reduction of cyclic N-sulfonyl ketimines catalyzed by B(C6F5)3, using commercially available methylphenylsilane as a reducing reagent under mild conditions has been developed. This reductive protoco
- Shi, Lei,Bao, Robert Li-Yuan,Zheng, Limin,Zhao, Rong
-
p. 6550 - 6556
(2019/10/22)
-
- Vancomycin-iridium (III) interaction: An unexplored route for enantioselective imine reduction
-
The chiral structure of antibiotic vancomycin (Van) was exploited as an innovative coordination sphere for the preparation of an IrCp* based hybrid catalysts. We found that Van is able to coordinate iridium (Ir(III)) and the complexation was demonstrated by several analytical techniques such as MALDI-TOF, UV, Circular dichroism (CD), Raman IR, and NMR. The hybrid system so obtained was employed in the Asymmetric Transfer Hydrogenation (ATH) of cyclic imines allowing to obtain a valuable 61% e.e. (R) in the asymmetric reduction of quinaldine 2. The catalytic system exhibited a saturation kinetics with a calculated efficiency of Kcat/KM = 0.688 h?1mM?1
- Facchetti, Giorgio,Pellegrino, Sara,Bucci, Raffaella,Nava, Donatella,Gandolfi, Raffaella,Christodoulou, Michael S.,Rimoldi, Isabella
-
-
- Synthesis of Sultams and Cyclic N-Sulfonyl Ketimines via Iron-Catalyzed Intramolecular Aliphatic C-H Amidation
-
Cyclic sulfonamides (sultams) play a unique role in drug discovery and synthetic chemistry. A direct synthesis of sultams by an intramolecular C(sp3)-H amidation reaction using an iron complex in situ derived from Fe(ClO4)2 and aminopyridine ligand is reported. This strategy features a readily available catalyst and tolerates a broad variety of substrates as demonstrated by 22 examples (up to 89% yield). A one-pot iron-catalyzed amidation/oxidation procedure for the synthesis of cyclic N-sulfonyl ketimines is also realized with up to 92% yield (eight examples). The synthetic utility of the method is validated by a gram-scale reaction and derivatization of the products to ring-fused sultams.
- Zhong, Dayou,Wu, Di,Zhang, Yan,Lu, Zhiwu,Usman, Muhammad,Liu, Wei,Lu, Xiuqiang,Liu, Wen-Bo
-
p. 5808 - 5812
(2019/08/26)
-
- Reductions of Imines Using Zirconocene Chloride Hydride
-
Herein, we describe the fast, chemoselective, and clean reduction of imines with zirconocene chloride hydride. The reaction works well on aromatic and enolizable aliphatic aldimines, as well as ketimines. A range of N-protecting groups and various functio
- Vargová, Denisa,Mudráková, Brigita,Némethová, Ivana,?ebesta, Radovan
-
p. 7606 - 7612
(2019/12/03)
-
- Cobalt-Catalyzed Transfer Hydrogenation of α-Ketoesters and N-Cyclicsulfonylimides Using H2O as Hydrogen Source
-
A Co-catalyzed effective transfer hydrogenation of various α-ketoesters and N-cyclicsulfonylimides by safe and environmentally benign H2O as hydrogen source is described. The reaction used easily available and easy to handle zinc metal as a reductant. Interestingly, the catalytic system does not require ligand for reduction of N-cyclicsulfonylimides. (Figure presented.).
- Gao, Yang,Zhang, Xuexin,Laishram, Ronibala Devi,Chen, Jingchao,Li, Kangkui,Zhang, Keyang,Zeng, Guangzhi,Fan, Baomin
-
supporting information
p. 3991 - 3997
(2019/08/02)
-
- Enantioselective Hydrogenation of Activated Aryl Imines Catalyzed by an Iron(II) P-NH-P′ Complex
-
Chiral amines are key building blocks in synthetic chemistry with numerous applications in the agricultural and pharmaceutical industries. Asymmetric imine hydrogenation, particularly with iridium catalysts, is well developed. However, imine reduction still remains challenging in the context of replacing such a precious metal with a cheap, nontoxic, and environmentally friendly substitute such as iron. Here, we report that an unsymmetrical iron P-NH-P′ catalyst that was previously shown to be effective for the asymmetric hydrogenation of aryl ketones is also a very effective catalyst for the asymmetric hydrogenation of prochiral aryl imines activated with N-diphenylphosphinoyl or N-tosyl groups. The P-NH-P′ abbreviation stands for (S,S)-PPh2CHPhCHPhNHCH2CH2PiPr2. Density functional theory results suggest that, surprisingly, the NH group on the catalyst activates and orients the imine to hydride attack by hydrogen bonding to the PO or SO group on the imine nitrogen, as opposed to the imine nitrogen itself. This may explain why N-Ph and N-Bu imines are not hydrogenated.
- Seo, Chris S. G.,Tannoux, Thibault,Smith, Samantha A. M.,Lough, Alan J.,Morris, Robert H.
-
p. 12040 - 12049
(2019/10/02)
-
- Diastereoselective synthesis of 1,3-disubstituted isoindolines and sultams via bronsted acid catalysis
-
The bis(trifluoromethane)sulfonimide (Tf2NH) catalyzed intramolecular hydroamidation of terminal alkynes is reported. The combination of Et3SiH and Tf2NH provides cis-1,3-disubstituted isoindolines and sultams in high yield (up to 98%) and high diastereoselectivity (up to 99?:?1 d.r.).
- Tao, Ye,Gilbertson, Scott R.
-
supporting information
p. 11292 - 11295
(2018/10/26)
-
- Chemoselective, enzymatic C-H bond amination catalyzed by a cytochrome P450 containing an Ir(Me)-PIX cofactor
-
Cytochrome P450 enzymes have been engineered to catalyze abiological C-H bond amination reactions, but the yields of these reactions have been limited by low chemoselectivity for the amination of C-H bonds over competing reduction of the azide substrate t
- Dydio, Pawel,Key, Hanna M.,Hayashi, Hiroki,Clark, Douglas S.,Hartwig, John F.
-
supporting information
p. 1750 - 1753
(2017/02/15)
-
- Synthesis of chiral sultams via palladium-catalyzed intramolecular asymmetric reductive amination
-
A novel palladium-catalyzed intramolecular reductive amination of ketones with weakly nucleophilic sulfonamides has been developed in the presence of a Br?nsted acid, giving a wide range of chiral γ-, δ-, and ε-sultams in high yields and up to 99% of enan
- Song, Bo,Yu, Chang-Bin,Ji, Yue,Chen, Mu-Wang,Zhou, Yong-Gui
-
supporting information
p. 1704 - 1707
(2017/02/10)
-
- An N-heterocyclic carbene iridium catalyst with metal-centered chirality for enantioselective transfer hydrogenation of imines
-
A cyclometalating N-heterocyclic carbene iridium complex featuring metal-centered chirality was designed and used for the asymmetric transfer hydrogenation (ATH) of imines. Four strongly σ-donating carbon-based substituents (2 carbenes and 2 phenyl moieti
- Li, Yanjun,Lei, Meng,Yuan, Wei,Meggers, Eric,Gong, Lei
-
supporting information
p. 8089 - 8092
(2017/07/22)
-
- Highly enantioselective synthesis of sultams via Pd-catalyzed hydrogenation
-
(Chemical Equation Presented) Using pd(cf3co2) 2/(S,S)-f-Binaphane as the catalyst, an efficient enantioselective synthesis of sultams was developed via asymmetric hydrogenation of the corresponding cyclic imines with high
- Yu, Chang-Bin,Wang, Da-Wei,Zhou, Yong-Gui
-
supporting information; experimental part
p. 5633 - 5635
(2009/12/08)
-
- Highly enantioselective Pd-catalyzed asymmetric hydrogenation of activated imines
-
(Chemical Equation Presented) Pd/bisphosphines complexes are highly effective catalysts for asymmetric hydrogenation of activated imines in trifluoroethanol. The asymmetric hydrogenation of N-diphenylphosphinyl ketimines 3 with Pd(CF3CO2)/(S)-SegPhos indicated 87-99% ee, and N-tosylimines 5 could gave 88-97% ee with Pd-(CF3CO 2)/(S)-SynPhos as a catalyst. Cyclic N-sulfonylimines 7 and 11 were hydrogenated to afford the useful chiral sultam derivatives in 79-93% ee, which are important organic synthetic intermediates and structural units of agricultural and pharmaceutical agents.
- Wang, You-Qing,Lu, Sheng-Mei,Zhou, Yong-Gui
-
p. 3729 - 3734
(2008/02/04)
-
- Intramolecular asymmetric amidations of sulfonamides and sulfamates catalyzed by chiral dirhodium(II) complexes
-
Enantioselective intramolecular amidation of aliphatic sulfonamides was achieved for the first time by means of chiral carboxylatodirhodium(II) catalysts in conjunction with PhI(OAc)2 and MgO in high yields and with enantioselectivities of up to 66% (Scheme 3, Table 1). The best results were obtained with [Rh2{(S)-nttI)4] and [Rh 2{(R)-ntv)4] as catalysts ((S)-nttl = (αS)-α- (tert-butyl)-1,3-dioxo-2H-benz[de]isoquinoline-2-acetato, (R)-nto = (αR)-α-isopropyl-1,3-dioxo-2H-benz[de] isoquinoline-2-acetato). In addition, these carboxylatodirhodium(II) catalysts were also efficient in intramolecular amidations of aliphatic sulfamates esters, although the enantioselectivity of these latter reactions was significantly lower (Scheme 4, Table 3).
- Fruit, Corinne,Mueller, Paul
-
p. 1607 - 1615
(2007/10/03)
-
- Sulfonamidyls. 5. Electron Spin Resonance Spectroscopic Evidence for Four- and Five-Membered-Ring Sulfonamidyls and Sulfonyl Nitroxides
-
Cyclic sulfonamidyl radicals, generated by photolysis of the N-bromo (or N-chloro) β- and γ-sultams 1-3 and of N-bromo-2,3-dihydro-1,2-benzisothiazole 1,1-dioxide (4) have been characterized by solution ESR studies.The nitrogen and β hyperfine splitting c
- Teeninga, Herman,Engberts, Jan B. F. N.
-
p. 537 - 542
(2007/10/02)
-