101-48-4Relevant academic research and scientific papers
Hypoiodous acid-catalyzed regioselective geminal addition of methanol to vinylarenes: synthesis of anti-Markovnikov methyl acetals
Peraka, Swamy,Mameda, Naresh,Marri, Mahender Reddy,Kodumuri, Srujana,Chevella, Durgaiah,Sripadi, Prabhakar,Nama, Narender
, p. 73732 - 73736 (2015)
A novel metal-free, catalytic geminal dimethoxylation of vinylarenes based on in situ generated HOI species from iodide salt and oxone is reported. The preliminary mechanistic investigations suggest that the key factor for achieving the anti-Markovnikov regioselectivity is the semipinacol rearrangement of an iodo functionalized intermediate, which is confirmed by an isotope labeling experiment. In addition, the reaction involves the de-iodination of a co-iodo intermediate via its oxidation to hypervalent iodine species rather than a common iodide abstraction by electrophiles. The HRESI-MS studies support the conversion of monovalent iodine containing intermediates to trivalent iodine intermediates during the catalytic conversion of aromatic alkenes into the corresponding terminal acetals.
An efficient protection of carbonyls and deprotection of acetals using decaborane
Lee, Seung Hwan,Lee, Ji Hee,Yoon, Cheol Min
, p. 2699 - 2703 (2002)
Carbonyls were efficiently converted to the corresponding dimethyl acetals at room temperature using trimethyl orthoformate and 1 mol% of decaborane under a nitrogen atmosphere. In turn, acetals were deprotected to the corresponding carbonyls using 1 mol% of decaborane in aqueous THF chemoselectively.
Termolecular Trapping of Benzylchlorocarbene by Methanol
Liu, Michael T. H.,Subramanian, Ramasamy
, p. 1062 - 1064 (1984)
The trapping of benzylchlorocarbene by methanol is termolecular leading to a frequency factor of 2 x 105 l2 mol-2 s-1 and an activation energy of -4.5 kcal mol-1 (18.8 kJ mol-1).
Atom-economical synthesis of 3,3,3-trifluoropropanal dialkyl acetals through Pd/C catalyzed acetalization of 3,3,3-trifluoropropene
Kang, Jian-Ping,Lu, Ju-You,Li, Yang,Wang, Zhi-Xuan,Mao, Wei,Lu, Jian
, p. 39387 - 39391 (2016)
A facile and efficient procedure for one-step synthesis of 3,3,3-trifluoropropanal dialkyl acetals from readily available 3,3,3-trifluoropropene (TFP) has been developed. The catalyst can be recycled for 4 times without obvious deactivation. This process provides a novel and atom-economical synthetic strategy for the preparation of functional CF3-containing compounds.
Reactivity of hydroxy- and aquo(hydroxy)-λ3-iodane-crown ether complexes
Miyamoto, Kazunori,Yokota, Yukie,Suefuji, Takashi,Yamaguchi, Kentaro,Ozawa, Tomoyuki,Ochiai, Masahito
, p. 5447 - 5453 (2014)
We have designed a series of hydroxy(aryl)-λ3-iodane-[18] crown-6 complexes, prepared from the corresponding iodosylbenzene derivatives and superacids in the presence of [18]crown-6, and have investigated their reactivities in aqueous media. These activated iodosylbenzene monomers are all non-hygroscopic shelf-storable reagents, but they maintain high oxidizing ability in water. The complexes are effective for the oxidation of phenols, sulfides, olefins, silyl enol ethers, and alkyl(trifluoro)borates under mild conditions. Furthermore, hydroxy-λ3-iodane-[18]crown-6 complexes serve as efficient progenitors for the synthesis of diaryl-, vinyl-, and alkynyl-λ3-iodanes in water. Other less polar organic solvents, such as methanol, acetonitrile, and dichloromethane, are also usable in some cases. Aqua-friendly iodosylbenzene equivalents: Hydroxy- and aquo(hydroxy)-λ3-iodane-[18]crown-6 complexes (see graphic), readily prepared from commercial PhI(OAc)2 or PhIO, serve as excellent oxygen atom donors toward olefins, phenols, sulfides, and alkyl(trifluoro)borates. They also serve as progenitors for diaryl-, vinyl-, and alkynyl-λ3-iodane-[18]crown-6 complexes. These reactions can be carried out in aqueous media under mild reaction conditions.
Palladium-catalyzed aerobic oxidation of terminal olefins with electron-withdrawing groups in scCO2
Jiang, Huan-Feng,Shen, Yan-Xia,Wang, Zhao-Yang
, p. 508 - 514 (2008)
Product control of palladium-catalyzed aerobic oxidation of terminal olefins with electron-withdrawing groups can be achieved through modifying reaction conditions. When the oxidant, such as CuCl2/O2, benzoquinone/O2 or O2, was present in scCO2, aerobic oxidation of terminal olefins goes smoothly. With enough MeOH and sufficient oxygen, acetalization preponderated over cyclotrimerization, while with little MeOH as co-solvent in scCO2 or no MeOH in DMF and an appropriate pressure of O2, cyclotrimerization of terminal olefins became the dominated reaction. When oxygen is absent and triethylamine was added into the reaction system, palladium-catalyzed C-N bond formation occurs to produce β-amino acid derivatives as the sole product.
Synthesis, structure and catalytic activity of a gold(i) complex containing 1,2-bis(diphenylphosphino)benzene monoxide
Hahn, Christine,Cruz, Leticia,Villalobos, Amanda,Garza, Liliana,Adeosun, Samuel
, p. 16300 - 16309 (2014)
The gold(i) complex [Au(dppbO)Cl] was synthesized by reaction of Na[AuCl4]·2H2O with 1,2-bis(diphenylphosphino)benzene (dppb) in the presence of water. This is a new method for the synthesis of a bisphosphine monoxide gold(i) complex. The new gold(i) complex was characterized by NMR spectroscopy and X-ray crystal structure analysis. In the solid state structure a relatively short contact between the oxygen atom of the phosphine oxide group and the gold center was observed. The catalytic activity of [Au(dppbO)Cl] was tested for three different intermolecular alkyne hydrofunctionalization reactions. Silver tetrafluoroborate was used as co-catalyst for halide abstraction. While the bisphosphine monoxide gold(i) complex showed moderate activity for the hydration of various alkynes and the hydroamination of phenyl acetylene, high activity was observed for the hydroarylation of ethylpropiolate. Electron-rich arenes add very fast to the C-C triple bond but with relatively low selectivity.
TRIMETHYLSILYLFLUOROSULFONATE (TMSOFs): AN ALTERNATIVE TO TMS TRIFLATE AS A SOURCE OF Me3Si+
Lipshutz, Bruce H.,Burgess-Henry, Jana,Roth, Gregory P.
, p. 995 - 998 (1993)
Generation of trimethylsilylfluorosulfonate in situ provides a useful source of TMS+, the reactivity of which is essentially equivalent to that of TMS triflate.Its precursors, in particular FSO3H, are less costly than those of TMSOTf or the reagent itself.
Substituent and Temperature Effects on the Reactions of Benzylchlorocarbene with Alcohol
Liu, Michael T. H.,Subramanian, Ramasamy
, p. 1233 - 1240 (1986)
The insertion reaction of the para-substituted benzylchlorocarbenes with methanol shows a second-order dependence in methanol, but only a first-order dependence in ethylene glycol.The results are consistent with a mechanism whereby the carbene inserts into the O-H bond of the alcohol dimer or oligomer by electrophilic attack of the carbene on the oxigenone pair to produce a reversibly formed ylide intermediate.The effects of the substituents indicate that electron-releasing group favours rearrangement while electron-withdrawing group facilitates insertion.Photolysis of halogenodiazirines in methanol at low temperatures give rise to V-shaped Arrhenius behaviour and the importance of N2 in influencing the reactivity of the singlet halogenocarbene in the matrix is demonstrated.
Method for the selective formation of dimethyl acetals in the presence of hydroxylamine
Mickelsen, Ky J.,Tajc, Chelsea M.,Greenwood, Kevin R.,Browder, Cindy C.
, p. 186 - 194 (2012)
An inexpensive and mild method for the formation of dimethyl acetals from the corresponding aldehydes is achieved using hydroxylamine and methanol under neutral conditions at room temperature. Notably, the reaction is selective for aldehydes in the presence of ketones, rendering this an example of a chemoselective acetalization. For saturated, sterically accessible aldehydes, catalytic amounts of hydroxylamine may be employed to attain the corresponding dimethyl acetal as the sole product in good to excellent yield. Unsaturated and hindered aldehydes required stoichiometric amounts of hydroxylamine but provided dimethyl acetals as the major product in typically excellent yield. In some cases, the corresponding oxime was also observed but may be separated from the acetal by flash column chromatography or distillation. The involvement of an intermediate oxime compound is postulated. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file. Taylor & Francis Group, LLC.
