25310-92-3Relevant academic research and scientific papers
Conjugate addition of acetal-derived benzyl radicals generated from low-valent titanium-mediated CO bond cleavage
Suga, Takuya,Nakamura, Masaharu,Takada, Ryusei,Ukaji, Yutaka
supporting information, p. 1258 - 1260 (2021/05/17)
A new method for the generation of benzyl radicals from acetals via low-valent titanium-mediated homolytic CO bond cleavage is presented. The low cost and availability of the developed titanium reagent enable efficient access to α-alkoxy carbon radical species via the developed reaction.
Iron-Catalyzed Radical Cleavage/C?C Bond Formation of Acetal-Derived Alkylsilyl Peroxides
Shiozaki, Yoko,Sakurai, Shunya,Sakamoto, Ryu,Matsumoto, Akira,Maruoka, Keiji
supporting information, p. 573 - 576 (2020/02/20)
A novel radical-based approach for the iron-catalyzed selective cleavage of acetal-derived alkylsilyl peroxides, followed by the formation of a carbon–carbon bond is reported. The reaction proceeds under mild reaction conditions and exhibits a broad substrate scope with respect to the acetal moiety and the carbon electrophile. Mechanistic studies suggest that the present reaction proceeds through a free-radical process involving carbon radicals generated by the homolytic cleavage of a carbon–carbon bond within the acetal moiety. A synthetic application of this method to sugar-derived alkylsilyl peroxides is also described.
Photocatalytic Reductive Formation of α-Tertiary Ethers from Ketals
Rossolini, Thomas,Ferko, Branislav,Dixon, Darren J.
supporting information, p. 6668 - 6673 (2019/09/03)
A general photocatalytic reductive strategy for the construction of unsymmetrical α-tertiary dialkyl ethers is reported. By merging Lewis acid-mediated ketal activation and visible-light photocatalytic reduction, in situ-generated α-alkoxy radicals were found to engage in addition reactions with a variety of olefinic partners. Good reaction efficiency is demonstrated with a range of ketals of aromatic and aliphatic ketones. Extension to acetal substrates is also described, demonstrating the overall synthetic utility of this methodology for complex ether synthesis.
A step forward in solvent knitting strategies: Ruthenium and gold phosphine complex polymerization results in effective heterogenized catalysts
Valverde-González, Antonio,Marchal, Gwendoline,Maya, Eva M.,Iglesias, Marta
, p. 4552 - 4560 (2019/09/09)
Porous polymers based on ruthenium and gold triphenylphosphine complexes (KPhos(Ru), KPhos(Ru)Bi, KPhos(AuCl) and KPhos(AuNTf2)) were prepared via a cost-effective solvent knitting method with [RuHClCO(PPh3)3] or AuXPPh3 (X = Cl, NTf2) as single monomers or combined with biphenyl, which represents a further approach to obtain heterogenized catalysts. The resulting materials mainly preserve the metal coordination environment of their parent complexes, are stable up to 350 °C and have reasonable surface areas (250-300 m2 g-1 for KPhos(Ru)-polymers). KPhos(Ru)s selectively catalyze the imination of alcohols in the presence of base and the results for KPhos(Au)s show they are effective for the intermolecular hydration and hydroamination of alkynes. These materials can be reused several times without significant loss of activity. This novel and simple method affords heterogenized catalysts that combine the reactivity and selectivity of their homogeneous counterparts with the stability and reusability of a heterogeneous framework.
Utilization of hexabromoacetone for protection of alcohols and aldehydes and deprotection of acetals, ketals, and oximes under UV irradiation
Chaiseeda, Kittichai,Chantharadet, Ladawan,Chavasiri, Warinthorn
, p. 1305 - 1323 (2017/10/30)
Hexabromoacetone (HBA) was efficiently used for the protection of alcohols and aldehydes and deprotection of benzaldehyde dimethyl acetal, solketal, and other acetals and ketals. In only 10?min, the protection of glycerol yielded 90% of solketal and protection of benzaldehyde gave 95% of benzaldehyde dimethyl acetal. The deprotection of benzaldehyde dimethyl acetal under UV irradiation gave over 90% yield of benzaldehyde within 15?s using only 2.5?mol% of HBA. HBA was also successfully used for deoximation. Solvent was found to play an important role in the efficiency of HBA for these reactions.
Stereoselective Ketone Rearrangements with Hypervalent Iodine Reagents
Malmedy, Florence,Wirth, Thomas
supporting information, p. 16072 - 16077 (2016/10/30)
The first stereoselective version of an iodine(III)-mediated rearrangement of arylketones in the presence of orthoesters is described. The reaction products, α-arylated esters, are very useful intermediates in the synthesis of bioactive compounds such as ibuprofen. With chiral lactic acid-based iodine(III) reagents product selectivities of up to 73 % ee have been achieved.
Mono- vs. dinuclear gold-catalyzed intermolecular hydroamidation
Serrano-Becerra, Juan M.,Maier, Alexander F. G.,Gonzalez-Gallardo, Sandra,Moos, Eric,Kaub, Christoph,Gaffga, Maximilian,Niedner-Schatteburg, Gereon,Roesky, Peter W.,Breher, Frank,Paradies, Jan
, p. 4515 - 4522 (2014/08/05)
Mono- and dinuclear gold catalysts were investigated in the intermolecular hydroamidation of olefins. Upon activation of [Ph3PAuCl] and [xantphos(AuCl)2] with various silver salts (AgOTf, Ag[BF 4], and Ag[SbF6]), diverging reactivity of the resulting cationic gold complexes was observed. It was found that both the binding ability of the counterion and the solvent have a significant impact on the reactivity of the mono- and dinuclear complexes. Copyright
Synthesis and structures of heterobimetallic Ir2M (M=Pd, Pt) sulfido clusters and their catalytic activity for regioselective addition of alcohols to internal 1-aryl-1-alkynes
Masui, Dai,Kochi, Takuya,Tang, Zhen,Ishii, Youichi,Mizobe, Yasushi,Hidai, Masanobu
, p. 69 - 79 (2007/10/03)
The heterobimetallic trinuclear suffido clusters [(Cp*Ir)2(μ3-S)2MCl2] (M = Pd (3), Pt (4); Cp* = η5-C5Me5) were synthesized from the dinuclear hydrogensulfido complex [Cp*IrCl(μ
Regioselective addition of alcohols to internal 1-aryl-1-alkynes catalyzed by a triangular heterobimetallic Ir2Pd sulfido cluster
Masui, Dai,Ishii, Youichi,Hidai, Masanobu
, p. 717 - 718 (2007/10/03)
The triangular heterobimetallic sulfido cluster [(Cp*Ir)2(μ3-S)2PdCl2] prepared from [PdCl2(cod)] and [Cp*IrCl(μ-SH)2IrCp*Cl] was found to catalyze the addition of alcohols to alkynes to give the corresponding ketals. In particular, internal 1-aryl-1-alkynes were transformed into the corresponding 2,2-dialkoxy-1-arylalkanes with high regioselectivity. The analogous Ir2PtS2 cluster proved to be much less selective.
Halogenative Deoxygenation of Ketones; Vinyl Bromides and/or gem-Dibromides by Cleavage of 1,3-Benzodioxoles (Ketone Phenylene Acetals) with Boron Tribromide
Napolitano, Elio,Fiaschi, Rita,Mastrorilli, Ettore
, p. 122 - 125 (2007/10/02)
Representative ketones 1 have been converted in generally good yields to the respective 1,3-benzodioxoles 5 by trans-acetalization of ketone dimethyl acetals with 1,2-dihydroxybenzene, and cleaved with boron tribromide. 1,3-Benzodioxoles derived from α-unbranched aliphatic ketones gave in general a mixture of vinyl bromides and gem-dibromides; pure gem-dibromides could be selectively obtained in most of cases using a suitable reaction time. 1,3-Benzodioxoles derived from α-branched ketones gave complex mixtures and their cleavage appears to be of little synthetic signifance. 1,3-Benzodioxoles of aromatic ketones gave vinyl bromides only.Aliphatic cyclic gem-dibromides 3 were converted to the respective vinyl bromides 2 by phase-transfer-catalysed dehydrobromination.
