- Copper-Catalyzed Modular Amino Oxygenation of Alkenes: Access to Diverse 1,2-Amino Oxygen-Containing Skeletons
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Copper-catalyzed alkene amino oxygenation reactions using O-acylhydroxylamines have been achieved for a rapid and modular access to diverse 1,2-amino oxygen-containing molecules. This transformation is applicable to the use of alcohols, carbonyls, oximes, and thio-carboxylic acids as nucleophiles on both terminal and internal alkenes. Mild reaction conditions tolerate a wide range of functional groups, including ether, ester, amide, carbamate, and halide. The reaction protocol allows for starting with free amines as the precursor of O-benzoylhydroxylamines to eliminate their isolation and purification, contributing to broader synthetic utilities. Mechanistic investigations reveal the amino oxygenation reactions may involve distinct pathways, depending on different oxygen nucleophiles.
- Hemric, Brett N.,Chen, Andy W.,Wang, Qiu
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supporting information
p. 1468 - 1488
(2019/01/25)
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- PdII-Catalyzed Oxidative Tandem aza-Wacker/Heck Cyclization for the Construction of Fused 5,6-Bicyclic N,O-Heterocycles
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A PdII-catalyzed oxidative tandem cyclization was developed for the construction of fused 5,6-bicyclic N, O-heterocycles. This reaction was enabled by the combined use of a 3-methylpyridine ligand and pentafluorobenzoic acid additive. A range of heterocyclic products with different substituents could be prepared in moderate to good yields via this methodology. Several transformations, including a scaled-up preparation of product 2 a, were also carried out showing the good applicability of our methodology.
- Ye, Chenghao,Kou, Xuezhen,Xia, Jingzhao,Yang, Guoqiang,Kong, Li,Wei, Quhao,Zhang, Wanbin
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supporting information
p. 1897 - 1901
(2018/07/31)
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- Aerobic Photooxidative Synthesis of β-Alkoxy Monohydroperoxides Using an Organo Photoredox Catalyst Controlled by a Base
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Transition-metal-free synthesis of β-alkoxy monohydroperoxides via aerobic photooxidation using an acridinium photocatalyst was developed. This method enables the synthesis of some novel hydroperoxides. The peroxide source is molecular oxygen, which is cost-effective and atomically efficient. Magnesium oxide plays an important role as a base in the catalytic system.
- Asano, Yuya,Nagasawa, Yoshitomo,Yamaguchi, Eiji,Itoh, Akichika
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supporting information
p. 409 - 412
(2018/02/21)
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- Preparation of isoindolinones via a palladium-catalyzed diamination
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A Pd(II)-catalyzed cyclization using oxidative olefin diamination was developed for the preparation of isoindolinones from ortho-olefinic N-methoxybenzamides. Using the optimized reaction conditions, the desired products were obtained in up to 90% yield using NFSI as the oxidant. This reaction provides an efficient and direct access to isoindolinones with amine functionality, an important drug skeleton.
- Li, Yu,Kou, Xuezhen,Ye, Chenghao,Zhang, Xinghua,Yang, Guoqiang,Zhang, Wanbin
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supporting information
p. 285 - 288
(2017/01/03)
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- Reversing the Regioselectivity of Halofunctionalization Reactions through Cooperative Photoredox and Copper Catalysis
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Halofunctionalization of alkenes is a classical method for olefin difunctionalization. It gives rise to adducts which are found in many natural products and biologically active molecules, and offers a synthetic handle for further manipulation. Classically, this reaction is performed with an electrophilic halogen source and leads to regioselective formation of the halofunctionalized adducts. Herein, we demonstrate a reversal of the native regioselectivity for alkene halofunctionalization through the use of an acridinium photooxidant in conjunction with a copper cocatalyst.
- Griffin, Jeremy D.,Cavanaugh, Cortney L.,Nicewicz, David A.
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supporting information
p. 2097 - 2100
(2017/02/15)
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- Palladium-Catalyzed Aerobic Aminooxygenation of Alkenes for Preparation of Isoindolinones
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A palladium-catalyzed intramolecular isoindolinone-forming aminooxygenation of alkenes with 1 atm of oxygen as oxidant is reported. A variety of functionalized alkenes and carboxylic acids can be used, and high yields were observed. Preliminary mechanistic studies revealed that the aminooxygenation products were formed through the oxidation of a C-PdII species using a strong oxidant, peroxide, which is generated in situ from a Pd(OAc)2/bpy/O2/HOAc catalytic system.
- Kou, Xuezhen,Li, Yu,Wu, Liang,Zhang, Xinghua,Yang, Guoqiang,Zhang, Wanbin
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supporting information
p. 5566 - 5569
(2015/12/01)
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- Lewis Acid Mediated Trifluoromethylthio Lactonization/Lactamization
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A highly selective Lewis acid mediated trifluoromethylthio lactonization/lactamization of olefins is described. The reaction was proposed to proceed via a thiiranium ion intermediate, which was further attacked by the carboxylic acid or amide to generate
- Xu, Chunfa,Shen, Qilong
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supporting information
p. 4561 - 4563
(2015/09/28)
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- Copper-mediated/catalyzed oxyalkylation of alkenes with alkylnitriles
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A copper-promoted oxyalkylation of alkenes with alkylnitriles has been developed. The protocol provides rapid access to phthalides (γ-lactones) or isochromanones (d-lactones) via the formation of a C(sp3)-C(sp3) and a C(sp3)-O bond with the generation of up to two quaternary carbon atoms. Mechanistic studies suggest that this reaction is initiated by the formation of the C(sp3)-C(sp3) bond rather than the C(sp3)-O bond. Catalytic conditions were subsequently developed using carboxylic acid as an internal nucleophile.
- Bunescu, Ala,Wang, Qian,Zhu, Jieping
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p. 14633 - 14636
(2015/01/09)
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- C3-symmetric cinchonine-squaramide-catalyzed asymmetric chlorolactonization of styrene-type carboxylic acids with 1,3-dichloro-5,5- dimethylhydantoin: An efficient method to chiral isochroman-1-ones
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A more practical and efficient catalytic asymmetric chlorolactonization of styrene-type carboxylic acids with 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) using C3-symmetric cinchonine-squaramide (CSCS) as organocatalyst has been developed. A series of chiral chloro-substituted isochroman-1-ones was obtained in excellent yields (up to 95%) and enantioselectivities (up to 99% ee), whwereby the results for chloro-substituted isochroman-1-ones are the best ever achieved. The catalyst can be recovered and reused for six cycles. Moreover, the chlorolactonization product 3b was further transformed to optically active bicyclic isochroman-1-one derivatives in high yield without losing the enantioselectivity. Furthermore, compounds 3e and 2n proved to be highly potent inhibitors of the HIV-1 in TZM-bl cells.
- Han, Xin,Dong, Chune,Zhou, Hai-Bing
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supporting information
p. 1275 - 1280
(2014/05/06)
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- Pd-Catalyzed intramolecular oxyalkynylation of alkenes with hypervalent iodine
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(Figure presented) The first example of intramolecular oxyalkynylation of nonactivated alkenes using oxidative Pd chemistry is reported. Both phenol and aromatic or aliphatic acid derivatives could be used under operator-friendly conditions (room temperature, technical solvents, under air). The discovery of the superiority of benzlodoxolone-derlved hypervalent iodine reagent 3d as an alkyne transfer reagent further expands the rapidly increasing utility of hypervalent iodine reagents in catalysis and is expected to have important implications for other similar processes.
- Nicolal, Stefano,Erard, Stephane,Gonzalez, Davinla Fernandez,Waser, Jerome
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supporting information; experimental part
p. 384 - 387
(2010/03/04)
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- Internally Masked Neopentyl Sulfonyl Ester Cyclization Release Prodrugs of Acamprosate, Compositions Thereof, and Methods of Use
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Internally masked neopentyl sulfonyl ester prodrugs of acamprosate, pharmaceutical compositions comprising such prodrugs, and methods of using such prodrugs and compositions thereof for treating diseases are disclosed. In particular, acamprosate prodrugs
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Page/Page column 43
(2009/04/24)
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- Polycyclen vom Triangulen-Typ, II. Dreifach ortho-verbrueckte Triphenylmethan-Derivate
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The syntheses of the new polycyclic systems 12,12c-dihydro-4,4,8,8,12,12-hexamethyl-4H,8H-dibenzopyrene (8), 11,11c-dihydro-7,7,11,11-tetramethyl-7H-naphthaceanthrylene (43), and 9,13b-dihydro-5,5,9,9-tetramethyl-1,13-ethano-5H-naphthanthracene (44) are reported.The spectroscopic data are in accordance with a pyramidal C3v-structure for 8, a similar Cs-structure for 43, and a flexible, helical C1-structure for 44.Furthermore, 8 can be transformed into its rapidly inverting pyramidal anion 11 and into its cation 9 which most probably is planar.
- Hellwinkel, Dieter,Aulmich, Gerhard,Melan, Michael
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