22835-64-9Relevant academic research and scientific papers
Complex Polyheterocycles and the Stereochemical Reassignment of Pileamartine A via Aza-Heck Triggered Aryl C-H Functionalization Cascades
Bower, John F.,Caiger, Lewis,García-Cárceles, Javier,Hazelden, Ian R.,Jones, Benjamin T.,Langer, Thomas,Lewis, Richard J.
supporting information, p. 15593 - 15598 (2021/10/12)
Structurally complex benzo- and spiro-fused N-polyheterocycles can be accessed via intramolecular Pd(0)-catalyzed alkene 1,2-aminoarylation reactions. The method uses N-(pentafluorobenzoyloxy)carbamates as the initiating motif, and this allows aza-Heck-type alkene amino-palladation in advance of C-H palladation of the aromatic component. The chemistry is showcased in the first total synthesis of the complex alkaloid (+)-pileamartine A, which has resulted in the reassignment of its absolute stereochemistry.
Chemodivergent Synthesis of One-Carbon-Extended Alcohols via Copper-Catalyzed Hydroxymethylation of Alkynes with Formic Acid
Jin, Xin,Fu, Hong-Chen,Wang, Mei-Yan,Huang, Shouying,Wang, Yue,He, Liang-Nian,Ma, Xinbin
supporting information, p. 4997 - 5001 (2021/06/28)
The development of selective catalytic reactions that utilize easily available reagents for the efficient synthesis of alcohols is a long-standing goal of chemical research. Here an intriguing strategy for the chemodivergent copper-catalyzed hydroxymethylation of alkynes with formic acid and hydrosilane has been developed. By simply tuning the amount of formic acid and reaction temperature, distinct one-carbon-extended primary alcohols, that is, allylic alcohols and β-branched alkyl alcohols, were produced with high levels of Z/E-, regio-, and enantioselectivity.
Magnesium chloride (MgCl2) catalyzed highly regioselective C-3 ring opening of 2,3 epoxy alcohols by N-nucleophile
Kumar, Amit,Panda, Gautam
, (2021/04/09)
We herein report Magnesium chloride (MgCl2) catalyzed first highly C3-selective ring-opening reaction of various 2,3-epoxy alcohols with assorted N-Nucleophiles and sodium azide to furnish 3-amino-1,2 diols and 3-azido-1,2 diols respectively in high yields under mild reaction conditions. This protocol attributes the use of catalytic amount of Magnesium chloride (MgCl2), simple reaction conditions, practical operation and broad functional group tolerance.
Copper-Catalyzed and Proton-Directed Selective Hydroxymethylation of Alkynes with CO2
Wang, Mei-Yan,Jin, Xin,Wang, Xiaofei,Xia, Shumei,Wang, Yue,Huang, Shouying,Li, Ying,He, Liang-Nian,Ma, Xinbin
supporting information, p. 3984 - 3988 (2020/12/25)
An intriguing strategy for copper-catalyzed hydroxymethylation of alkynes with CO2 and hydrosilane was developed. Switched on/off a proton source, for example, tBuOH, direct hydroxymethylation and reductive hydroxymethylation could be triggered selectively, delivering a series of allylic alcohols and homobenzylic alcohols, respectively, with high levels of Z/E, regio- and enantioselectivity. Such a selective synthesis is attributed to the differences in response of vinylcopper intermediate to proton and CO2. The protonation of vinylcopper species is demonstrated to be prior to hydroxymethylation, thus allowing a diversion from direct alkyne hydroxymethylation to reductive hydroxymethylation in the presence of suitable proton.
Highly-functionalized arene synthesis based on palladium on carbon-catalyzed aqueous dehydrogenation of cyclohexadienes and cyclohexenes
Yasukawa, Naoki,Yokoyama, Hiroki,Masuda, Masahiro,Monguchi, Yasunari,Sajiki, Hironao,Sawama, Yoshinari
supporting information, p. 1213 - 1217 (2018/03/28)
Transition metal-catalyzed dehydrogenation is a clean oxidation method requiring no additional oxidants. We have accomplished a heterogeneous Pd/C-catalyzed aqueous dehydrogenation of 1,4-cyclohexadienes and cyclohexenes to give the corresponding highly-functionalized arenes. Furthermore, various arenes could be efficiently constructed in a one-pot manner via a Diels-Alder reaction and the following dehydrogenation.
Ni-Catalyzed regio- and stereoselective addition of arylboronic acids to terminal alkynes with a directing group tether
Hari Babu, Madala,Ranjith Kumar, Gadi,Kant, Ruchir,Sridhar Reddy, Maddi
supporting information, p. 3894 - 3897 (2017/04/04)
Addition of arylboronic acids to directing group tethered acetylenes in a regio and stereoselective manner using an inexpensive catalytic system is achieved for the first time to access highly sought after allyl/homoallyl alcohol/amine units. The apparent vinylnickel intermediate was successfully trapped by the Michael electrophiles to get defined tri- and tetra-substituted olefins. An interesting selectivity switch was observed with internal alkynes.
Systematic methodology for the development of biocatalytic hydrogen-borrowing cascades: Application to the synthesis of chiral α-substituted carboxylic acids from α-substituted α,β-unsaturated aldehydes
Knaus, Tanja,Mutti, Francesco G.,Humphreys, Luke D.,Turner, Nicholas J.,Scrutton, Nigel S.
, p. 223 - 233 (2015/02/19)
Ene-reductases (ERs) are flavin dependent enzymes that catalyze the asymmetric reduction of activated carbon-carbon double bonds. In particular, α,β-unsaturated carbonyl compounds (e.g. enals and enones) as well as nitroalkenes are rapidly reduced. Conversely, α,β-unsaturated esters are poorly accepted substrates whereas free carboxylic acids are not converted at all. The only exceptions are α,β-unsaturated diacids, diesters as well as esters bearing an electron-withdrawing group in α- or β-position. Here, we present an alternative approach that has a general applicability for directly obtaining diverse chiral α-substituted carboxylic acids. This approach combines two enzyme classes, namely ERs and aldehyde dehydrogenases (Ald-DHs), in a concurrent reductive-oxidative biocatalytic cascade. This strategy has several advantages as the starting material is an α-substituted α,β-unsaturated aldehyde, a class of compounds extremely reactive for the reduction of the alkene moiety. Furthermore no external hydride source from a sacrificial substrate (e.g. glucose, formate) is required since the hydride for the first reductive step is liberated in the second oxidative step. Such a process is defined as a hydrogen-borrowing cascade. This methodology has wide applicability as it was successfully applied to the synthesis of chiral substituted hydrocinnamic acids, aliphatic acids, heterocycles and even acetylated amino acids with elevated yield, chemo- and stereo-selectivity. A systematic methodology for optimizing the hydrogen-borrowing two-enzyme synthesis of α-chiral substituted carboxylic acids was developed. This systematic methodology has general applicability for the development of diverse hydrogen-borrowing processes that possess the highest atom efficiency and the lowest environmental impact. This journal is
Asymmetric epoxidation of allylic alcohols catalyzed by vanadium-binaphthylbishydroxamic acid complex
Noji, Masahiro,Kobayashi, Toshihiro,Uechi, Yuria,Kikuchi, Asami,Kondo, Hisako,Sugiyama, Shigeo,Ishii, Keitaro
, p. 3203 - 3210 (2015/03/30)
A vanadium-binaphthylbishydroxamic acid (BBHA) complex-catalyzed asymmetric epoxidation of allylic alcohols is described. The optically active binaphthyl-based ligands BBHA 2a and 2b were synthesized from (S)-1,1'-binaphthyl-2,2'dicarboxylic acid and N-substituted-O-trimethylsilyl (TMS)-protected hydroxylamines via a one-pot, three-step procedure. The epoxidations of 2,3,3-trisubstituted allylic alcohols using the vanadium complex of 2a were easily performed in toluene with a TBHP water solution to afford (2R)-epoxy alcohols in good to excellent enantioselectivities.
Highly enantioselective hydrogenation of 2-substituted-2-alkenols catalysed by a ChenPhos-Rh complex
Wang, Quanjun,Liu, Xueying,Liu, Xian,Li, Bin,Nie, Huifang,Zhang, Shengyong,Chen, Weiping
supporting information, p. 978 - 980 (2014/01/06)
Highly enantioselective hydrogenation of a variety of 2-substituted-2- alkenols has been achieved using a ChenPhos-Rh complex as catalyst, giving ≥99% ee for most substrates. Optically active antifungal agent amorolfine was first synthesised using hydrogenation as the key step. This journal is
Copper-catalyzed hydrocarboxylation of alkynes using carbon dioxide and hydrosilanes
Fujihara, Tetsuaki,Xu, Tinghua,Semba, Kazuhiko,Terao, Jun,Tsuji, Yasushi
, p. 523 - 527 (2011/03/16)
Getting a fix: The copper-catalyzed hydrocarboxylation of alkynes using carbon dioxide in the presence of a hydrosilane, which serves as a reducing agent, has been developed (see scheme). Copper fluorides bearing N-heterocyclic carbene ligands such as IMes and Cl2IPr show high catalytic activities.
