5650-34-0Relevant academic research and scientific papers
A practical method for the aziridination of α,β-unsaturated carbonyl compounds with a simple carbamate utilizing sodium hypochlorite pentahydrate
Minakata, Satoshi,Umeda, Takehiro
, p. 22120 - 22124 (2021/07/02)
The efficient formation oftert-butylN-chloro-N-sodio-carbamate by the reaction of simpletert-butyl carbamate with sodium hypochlorite pentahydrate (NaOCl·5H2O) would be a practical and green method for the aziridination of α,β-unsaturated carbo
Chiral Manganese Aminopyridine Complexes: the Versatile Catalysts of Chemo- and Stereoselective Oxidations with H2O2
Ottenbacher, Roman V.,Talsi, Evgenii P.,Bryliakov, Konstantin P.
, p. 78 - 90 (2017/10/06)
In the last decade, manganese(II) complexes with N-donor tetradentate aminopyridine ligands emerged as efficient catalysts of enantioselective epoxidation of olefins and direct selective oxidation of C?H groups in complex organic molecules, with environmentally benign oxidant hydrogen peroxide. In this personal account, we summarize the progress of these catalysts with regard to ligands design, structure-reactivity correlations, evaluation of the substrate scope, as well as mechanistic studies, shedding light on the nature of active sites and the mechanisms of selective oxygenations. Several practically promising catalytic syntheses with the aid of Mn aminopyridine catalysts are exemplified.
Highly Efficient Oxidation of Secondary Alcohols to Ketones Catalyzed by Manganese Complexes of N4 Ligands with H2O2
Shen, Duyi,Miao, Chengxia,Xu, Daqian,Xia, Chungu,Sun, Wei
supporting information, p. 54 - 57 (2015/07/28)
The manganese complex Mn(S-PMB)(CF3SO3)2 was proven to be highly efficient in the catalytic oxidation of several benzylic and aliphatic secondary alcohols with H2O2 as the oxidant and acetic acid as the additive. A maximum turnover number of 4700 was achieved in the alcohol oxidation. In addition, the Hammett analysis unveiled the electrophilic nature of this manganese catalyst with N4 ligand. (Chemical Equation Presented).
Application of a C-C Bond-Forming Conjugate Addition Reaction in Asymmetric Dearomatization of β-Naphthols
Yang, Dongxu,Wang, Linqing,Kai, Ming,Li, Dan,Yao, Xiaojun,Wang, Rui
, p. 9523 - 9527 (2015/08/11)
A C-C bond-forming conjugate reaction was successfully applied to the enantioselective dearomatization of β-naphthols. A C(sp2)-C(sp3) bond is formed by using propargylic ketones as reactive partners. Good to excellent Z/E ratios and ee values were obtained by employing an in situ generated magnesium catalyst. Further transformations of the Z-configured C-C double bond in the products were achieved under mild reaction conditions. Moreover, the stereocontrolling element of this magnesium-catalyzed dearomatization reaction was explored by computational chemistry.
Indium-promoted chemo- and diastereoselective allylation of α,β-epoxy ketones with potassium allyltrifluoroborate
Nowrouzi, Farhad,Janetzko, John,Batey, Robert A.
supporting information; experimental part, p. 5490 - 5493 (2011/02/27)
A practical method for the chemo- and diastereoselective allylation of α,β-epoxy ketones has been developed by using the convenient air and moisture stable reagent potassium allyltrifluoroborate. Indium metal was found to promote addition in stoichiometric or catalytic amounts, to afford α,β-epoxyhomoallylic tertiary alcohols in high yields and diastereoselectivities, without competing ring-scission of the epoxide.
Dimethyl sulfoxide pivaloyl chloride: A new reagent for oxidation of alcohols to carbonyls
Dubey, Abhishek,Kandula, Subba Rao V.,Kumar, Pradeep
, p. 746 - 753 (2008/09/16)
An efficient procedure for conversion of alcohols to the corresponding carbonyl compounds, an alternative to the classical Swern oxidation, is described. Pivaloyl chloride is employed as a mild and inexpensive electrophile. A possible reaction mechanism is proposed. Copyright Taylor & Francis Group, LLC.
Homologation of vicinal polyketone networks to epoxy ketones with diazomethane
Hartung, Ryan E.,Paquette, Leo A.
, p. 23 - 26 (2007/10/03)
Admixture of vicinal di-, tri-, and tetraketones with ethereal diazomethane results in one-time methylene transfer to the less hindered face of the sterically most accessible and electron-deficient carbonyl group to deliver epoxy ketones in a highly selec
A Highly Efficient Ruthenium-Catalyzed Rearrangement of α,β-Epoxyketones to 1,2-Diketones
Chang, Chia-Lung,Kumar, Manyam Praveen,Liu, Rai-Shung
, p. 2793 - 2796 (2007/10/03)
TpRuPPh3(CH3CN)2PF6 catalyzed the efficient rearrangement of α,β-epoxyketones to 1,2-diketones. Unlike a previously reported iron catalyst, the reaction in this case is applicable not only to 1,2-disubstituted epoxides but also to mono- and trisubstituted epoxides and tolerates oxygen functionalities. The sterically crowded and highly basic tris(1-pyrazolyl)borate (Tp) ligand of the ruthenium catalyst might account for its high selectivity toward 1,2-diketone rather than 1,3-diketone.
SET photochemistry of flavin-cyclopropylamine systems. Models for proposed monoamine oxidase inhibition mechanisms
Kim, Jong-Man,Bogdan, Michael A.,Mariano, Patrick S.
, p. 9251 - 9257 (2007/10/02)
Single electron transfer (SET) induced photochemical reactions of 3-methyllumiflavin (3-MLF) with the cyclopropylamines, trans-2-phenylcyclopropylamine (1) and 1-phenylcyclopropylamine (4), have been explored with the aim of defining the nature of and mechanisms for the reaction pathways followed. The excited-state SET processes probed in this investigation were designed to model those proposed previously for inactivation of the flavine-containing enzyme, monoamine oxidase, by these same cyclopropylamines. Irradiation of 3-MLF in an N2-purged solution containing cyclopropylamine 4 leads to generation of the C-4a,N-5-propanodihydrofiavin 14 as the major primary photoproduct. This substance, which is formed by an SET-promoted radical coupling mechanism, is transformed to the C-4a-(benzoylethyl)dihydroflavin 6 under hydrolytic conditions. Several other minor, cyclopropylamine-derived products are also generated in this reaction, again via radical pathways. In contrast, irradiation of an air-saturated solution of 3-MLF and 4 produces the epoxy ketone 8 efficiently. In this reaction, 3-MLF serves as an SET photosensitizer for the oxidative ring-opening reaction that converts 4 to 8. Finally, the C-4a,N-5-propanodihydroflavin adducts 17 and 18 are generated along with substances arising by secondary reaction of a primary product, cinnamaldehyde (20), when 3-MLF is irradiated in an N2-purged solution containing the cyclopropylamine 1. Mechanistic aspects of these bona fide SET flavin-cyclopropylamine reactions and their possible relationship to proposals made earlier about the nature of and mechanisms for monoamine oxidase inactivation by the same cyclopropylamines are discussed.
Organosilicon compounds with functional groups proximate to silicon. XVII. Synthetic and mechanistic aspects of the lithiation of α,β-epoxyalkylsilanes and related α-heterosubstituted epoxides
Eisch, John J.,Galle, James E.
, p. 293 - 314 (2007/10/02)
A series of α-heterosubstituted epoxides, , has been found to undergo lithiation in the temperature range of -75 to -115 deg C at the C-H bond of the epoxide.The substituent Z could be Me3Si, Ph3Si, n-Bu3Sn, Ph3Sn, PhSO2, (OEt)2PO and Ph; the groups R and R' were H, Ph and n-C6H13; and the lithiating reagents were n-butyllithium, t-butyllithium and lithium diisopropylamide in donor media of THF or TMEDA.The lithiation occurs with retention of configuration and the resulting lithio-epoxide is unstable above 0 deg C, decomposing in a carbenoid manner.The lithiation is facile except for compounds where Z and R (an alkyl or aryl) are cis-oriented; where Z = R3Sn, lithiation occurs by tin-lithium, rather than hydrogen-lithium, exchange.The lithio-epoxides thereby generated can be quenched with various reagents to yield epoxides where the epoxide H has been replaced by D, Me3Sn, R, RCO and COOH.The utility of this procedure in organic synthesis is emphasized.Finally, the possible explanations for the acidity of such α-heterosubstituted epoxides and for the relative stability of the derived lithio-epoxides are considered and assessed.
