99522-43-7Relevant academic research and scientific papers
Generation of Alkoxyl Radicals by Photoredox Catalysis Enables Selective C(sp3)-H Functionalization under Mild Reaction Conditions
Zhang, Jing,Li, Yang,Zhang, Fuyuan,Hu, Chenchen,Chen, Yiyun
supporting information, p. 1872 - 1875 (2016/02/03)
Reported herein is the first visible-light-induced formation of alkoxyl radicals from N-alkoxyphthalimides, and the Hantzsch ester as the reductant is crucial for the reaction. The selective hydrogen atom abstraction by the alkoxyl radical enables C(sp3)-H allylation and alkenylation reactions under mild reaction conditions at room temperature. Broad substrate variations, including a structurally complexed steroid, undergo the C(sp3)-H functionalization reaction effectively with high regio- and chemoselectivity.
Catalytic olefin hydroamination with aminium radical cations: A photoredox method for direct C-N bond formation
Musacchio, Andrew J.,Nguyen, Lucas Q.,Beard, G. Hudson,Knowles, Robert R.
supporting information, p. 12217 - 12220 (2014/12/09)
While olefin amination with aminium radical cations is a classical method for C-N bond formation, catalytic variants that utilize simple 2° amine precursors remain largely undeveloped. Herein we report a new visible-light photoredox protocol for the intramolecular anti-Markovnikov hydroamination of aryl olefins that proceeds through catalytically generated aminium radical intermediates. Mechanistic studies are consistent with a process involving amine oxidation via electron transfer, turnover-limiting C-N bond formation, and a second electron transfer step to reduce a carbon-centered radical, rendering the overall process redox-neutral. A range of structurally diverse N-aryl heterocycles can be prepared in good to excellent yields under conditions significantly milder than those required by conventional aminium-based protocols.
Intramolecular cycloaddition of O-tert-butyldimethylsilyloximes in the presence of BF3-OEt2
Tamura, Osamu,Mitsuya, Takahiro,Huang, Xin,Tsutsumi, Yoshiyuki,Hattori, Sanae,Ishibashi, Hiroyuki
, p. 10720 - 10725 (2007/10/03)
Intramolecular cycloaddition of novel 1,3-dipoles, N-boranonitrones, was examined. Treatment of O-tert-butyldimethylsilyloximes 9-12 having olefin moieties with 2 equiv of BF3·OEt2 generated N-boranonitrones, which underwent intramolecular cycloaddition to afford N-nonsubstituted cycloadducts 16 (and/or 18) after extractive workup. Despite the Lewis-acidic conditions, the olefin geometry of the substrates was retained in the cycloadducts in the present cycloaddition. The electronic nature of the N-boranonitrones appeared to be electrophilic. In the case of substrate 11c, having an electron-donating methyl group at an internal position of the olefin moiety, the cycloaddition gave the bridged cycloadduct 18b. The cycloaddition proceeded at relatively low temperature, and the diastereoselectivity was high.
Highly selective intra- and intermolecular coupling reactions of diazo compounds to form cis-alkenes using a ruthenium porphyrin catalyst
Li, Gong-Yong,Che, Chi-Ming
, p. 1621 - 1623 (2007/10/03)
[Ru(2,6-Cl2TPP)(CO)] catalyzed intramolecular coupling reactions of bisdiazoacetates and intermolecular coupling reactions of monodiazoacetates to afford the coupling products in up to 76% and 93% yields, respectively. Only the cis isomers were obtained from the reactions. Employing such a ruthenium-catalyzed coupling reaction of a diazo compound as a key step allowed the synthesis of Patulolide B in 67% yield with a ratio of >40:1 against its trans isomer.
Tributyltin hydride-mediated radical cyclisation of aldehydes and unsaturated ketones: The synthesis of hydroxy tetrahydrofurans, chromanols and related compounds
Bebbington, David,Bentley, Jon,Nilsson, Paul A.,Parsons, Andrew F.
, p. 8941 - 8945 (2007/10/03)
The tributyltin hydride-mediated cyclisation of unsaturated ethers bearing an aldehyde or α,β-unsaturated ketone group is reported. Cyclisation proceeds via addition of the tributyltin radical to the carbonyl double bond and the resultant O-stannyl ketyl can add intramolecularly to electron-rich double bonds to form hydroxy tetrahydrofurans, chromanols or related compounds. (C) 2000 Elsevier Science Ltd.
A new free radical route to oximes using alkyl halides, hexabutylditin and readily available nitrite esters
Kizil, Murat,Murphy, John A.
, p. 16847 - 16858 (2007/10/03)
Reaction of alkyl radicals (generated from alkyl iodides or benzyl bromides with hexabutylditin) in the presence of alkyl nitrites affords oximes as products in good yields.
