67472-23-5Relevant articles and documents
Visible Light-Promoted Recyclable Carbon Nitride-Catalyzed Dioxygenation of β,γ-Unsaturated Oximes
Fu, Xiao-Yang,Si, Ya-Feng,Qiao, Li-Peng,Zhao, Yu-Fen,Chen, Xiao-Lan,Yu, Bing
supporting information, p. 574 - 580 (2021/11/13)
A visible-light-induced dioxygenation of β,γ-unsaturated oximes for the synthesis of diverse useful isoxazolines bearing a hydroxyl moiety was developed by employing graphitic carbon nitride (g-C3N4) as a heterogeneous photocatalyst under an air atmosphere. Noted that, the eminent advantages of this metal-free protocol include step economy, easy operation, a recyclable photocatalyst, external reductant-/oxidant-free and mild reaction conditions. Additionally, mechanistic studies indicated hydroxyl radical was generated under the photocatalysis of g-C3N4.
Synthesis of Flavanones via Palladium(II)-Catalyzed One-Pot β-Arylation of Chromanones with Arylboronic Acids
Cho, Yang Yil,Jang, Hyu Jeong,Kim, Dong Hwan,Kim, Nam Yong,Kim, Nam-Jung,Kim, Young Min,Lee, Soo Jin,Lee, Yong Sup,Park, Boyoung Y.,Son, Seung Hwan,Yoo, Hyung-Seok
supporting information, p. 10012 - 10023 (2019/08/30)
A total of 47 flavanones were expediently synthesized via one-pot β-arylation of chromanones, a class of simple ketones possessing chemically unactivated β sites, with arylboronic acids via tandem palladium(II) catalysis. This reaction provides a novel route to various flavanones, including natural products such as naringenin trimethyl ether, in yields up to 92percent.
Chemoselective Carbonyl Allylations with Alkoxyallylsiletanes
Spaltenstein, Paul,Cummins, Elizabeth J.,Yokuda, Kelly-Marie,Kowalczyk, Tim,Clark, Timothy B.,O'Neil, Gregory W.
, p. 4421 - 4428 (2019/03/26)
Alkoxyallylsiletanes are capable of highly chemo- and diastereoselective carbonyl allylsilylations. Reactive substrates include salicylaldehydes and glyoxylic acids. Chemoselectivity in these reactions is thought to arise from a mechanism involving first exchange of the alkyoxy group on silicon with a substrate hydroxyl followed by activation of a nearby carbonyl by the Lewis acidic siletane and intramolecular allylation. In this way, substrates containing multiple reactive carbonyl groups (e.g., dialdehyde or triketone) can be selectively monoallylated, even overcoming inherent electrophilicity bias.
Active bismuth mediated allylation of carbonyls/N-tosyl aldimines and propargylation of aldehydes in water
Sawkmie, Micky Lanster,Paul, Dipankar,Khatua, Snehadrinarayan,Chatterjee, Paresh Nath
, (2019/06/08)
Abstract: Active bismuth is synthesized by the chemical reduction of bismuth trichloride using freshly prepared sodium stannite solution as the reducing agent at room temperature. The as-synthesized active bismuth is applied as a reagent for the synthesis of homoallyl alcohol/homopropargyl alcohol from allyl bromide/propargyl bromide and carbonyl compounds in water at 50°C. The homoallyl amines are also synthesized from N-tosyl aldimines and allyl bromide using active bismuth reagent in good yields. No assistance of organic co-solvent, co-reagent, phase transfer catalyst or inert atmosphere is required for this reaction. The waste bismuth material obtained after the completion of the organic reaction can be reduced to active bismuth by sodium stannite solution and successfully reused for mediating the allylation of aldehydes. Graphical Abstract:: Synopsis Active bismuth mediated allylation/crotylation of aldehydes is developed in water to get homoallyl alcohols. The method is also applied for the allylation of N-tosyl aldimines and propargylation of aldehydes in water to achieve the homoallyl amines and homopropargyl alcohols, respectively. The reactions do not require the assistance of organic co-solvent, co-reagent, phase transfer catalyst or inert atmosphere.[Figure not available: see fulltext.].
Highly sulphated cellulose: a versatile, reusable and selective desilylating agent for deprotection of alcoholic TBDMS ethers
Dachavaram, Soma Shekar,Penthala, Narsimha R.,Calahan, Julie L.,Munson, Eric J.,Crooks, Peter A.
, p. 6057 - 6062 (2018/09/06)
A mild, efficient and rapid protocol was developed for the deprotection of alcoholic TBDMS ethers using a recyclable, eco-friendly highly sulphated cellulose sulphate acid catalyst in methanol. This acid catalyst selectively cleaves alcoholic TBDMS ethers in bis-TBDMS ethers containing both alcoholic and phenolic TBDMS ether moieties.
Catalytic Nucleophilic Allylation Driven by the Water-Gas Shift Reaction
Denmark, Scott E.,Matesich, Zachery D.,Nguyen, Son T.,Milicevic Sephton, Selena
, p. 23 - 48 (2018/02/19)
The ruthenium-catalyzed allylation of aldehydes with allylic pro-nucleophiles has been demonstrated to be an efficient means to form carbon-carbon bonds under mild conditions. The evolution of this reaction from the initial serendipitous discovery to its general synthetic scope is detailed, highlighting the roles of water, CO, and amine in the generation of a more complete catalytic cycle. The use of unsymmetrical allylic pro-nucleophiles was shown to give preferential product formation through the modulation of reaction conditions. Both (E)-cinnamyl acetate and vinyl oxirane were efficiently used to form the anti-branched products (up to >20:1 anti/syn) and E-linear products (up to >20:1 E/Z) in high selectivity with aromatic, α,β-unsaturated, and aliphatic aldehydes, respectively. Attempts to render the reaction enantioselective are highlighted and include enantioenrichment of up to 75:25 for benzaldehyde.
Organocatalytic Asymmetric Domino Michael/Acyl Transfer Reaction Between α-Nitroketones and in situ-Generated ortho-Quinone Methides: Route to 2-(1-Arylethyl)phenols
Gharui, Chandan,Behera, Debasmita,Pan, Subhas Chandra
supporting information, p. 4502 - 4508 (2018/11/10)
An organocatalytic asymmetric domino Michael/acyl transfer reaction between α-nitroketones and o-quinone methides is disclosed. o-Quinone methides are generated in situ from 2-sulfonylmethylphenols in basic medium. With 10 mol% of bifunctional squaramide catalyst, high yields and excellent enantioselectivities are achieved for a variety of O-acyl 2-(1-arylethyl)phenols under mild reaction condition. (Figure presented.).
Dual roles of sulfonyl hydrazides in the catalyst-free sulfonylation of unsaturated benzylic alcohols in water
Xu, Kun,Li, Lijun,Yan, Wen,Wu, Yuanyuan,Wang, Zhiqiang,Zhang, Sheng
, p. 4494 - 4497 (2017/10/13)
An atom-economical sulfonylation of unsaturated benzylic alcohols in water is described. In this transformation, dual roles of sulfonyl hydrazides serving as both a sulfonyl source and a reductant have been demonstrated, which enabled a facile and green method to synthesize alkyl sulfones from unsaturated benzylic alcohols. Moreover, this approach provides a practical access to deuterated alkanes from the corresponding alkenes by employing the combination of sulfonyl hydrazides and the solvent D2O.
Enantioselective Reactions of 2-Sulfonylalkyl Phenols with Allenic Esters: Dynamic Kinetic Resolution and [4+2] Cycloaddition Involving ortho-Quinone Methide Intermediates
Chen, Ping,Wang, Kai,Guo, Wengang,Liu, Xianghui,Liu, Yan,Li, Can
supporting information, p. 3689 - 3693 (2017/03/21)
We report herein a dynamic kinetic resolution (DKR) involving ortho-quinone methide (o-QM) intermediates. In the presence of Et3N and the cinchonine-derived nucleophilic catalyst D, the DKR of 2-sulfonylalkyl phenols with allenic esters afforded chiral benzylic sulfones in 57–79 % yield with good to excellent enantioselectivity (85–95 % ee). Furthermore, with 2-(tosylmethyl)sesamols or 2-(tosylmethyl)naphthols, from which stable o-QM substrates can be generated, a formal [4+2] cycloaddition delivered 4-aryl- or alkyl-substituted chromans with excellent enantioselectivity (88–97 % ee).
A practical procedure of low valent tin mediated Barbier allylation of aldehydes in wet solvent
Vilanova, Conxín,Sánchez-Péris, María,Roldán, Steven,Dhotare, Bhaskar,Carda, Miguel,Chattopadhyay, Angshuman
, p. 6562 - 6567 (2013/11/19)
Use of aluminium as the reducing metal in spontaneous bimetal redox reaction has been elegantly exploited for allylation/crotylation of aldehydes in wet solvent. Here, low valent tin was prepared in situ by reduction of SnCl2·2H2O wi
