50648-70-9Relevant academic research and scientific papers
Ruthenium-catalysed synthesis of chiral exocyclic allylic alcoholsviachemoselective transfer hydrogenation of 2-arylidene cycloalkanones
Zhang, Kaili,Liu, Qixing,He, Renke,Chen, Danyi,Deng, Zhangshuang,Huang, Nianyu,Zhou, Haifeng
supporting information, p. 1628 - 1632 (2021/03/09)
An exclusive asymmetric reduction of C=O bonds of 2-arylidene four-, five-, six-, and seven-membered cycloalkanones has been studied systematically. The asymmetric transfer hydrogenation was performed using a robust and commercially available chiral diamine-derived ruthenium complex as a catalyst and HCOOH/Et3N as a hydrogen source under mild conditions, giving 51 examples of chiral exocyclic allylic alcohols in up to 96% yield and 99% ee. This method was also applicable to the gram-scale synthesis of the active intermediates of the anti-inflammatory loxoprofen and natural product (?)-goniomitine.
Rh(I)-catalyzed ring-opening of cyclobutanols via C–C bond activation: Synthesis of cis-olefin with a remote aldehyde
Nie, Yu,Chen, Jianzhong,Zhang, Wanbin
supporting information, (2019/09/03)
A Rh(I)-catalyzed ring-opening of cyclobutanols has been developed with ring opening products bearing cis-olefin and a remote aldehyde. Various substrates bearing different substituted aryl groups, heterocyclic groups and alkyl groups were compatible with
Installation of a chiral side chain to a 2-alkylidene-1-cycloalkan-1-ol unit by using allylic substitution
Feng, Chao,Kobayashi, Yuichi
, p. 6666 - 6676 (2013/11/06)
The allylic substitution of optically active exocyclic allylic esters of cyclopentane and cyclohexane with ArMgBr-based copper reagents (Ar = aryl) was examined. ArMgBr/Cu(acac)2 in a 2:1 ratio was an adequate reagent to produce the anti-SN2' products efficiently in terms of regioselectivity (95-99a€‰%), chirality transfer (91-99a€‰%), and yield (71-91a€‰%). The Ar groups that were successfully installed include Ph and p-tolyl, those with electron-donating (i.e., p-MeOC6H4) and electron-withdrawing groups (i.e., p-FC6H4), and those with sterically demanding groups (i.e., o-tolyl, o-MeOC6H 4). In an examination of an alkyl reagent, BuMgBr/CuBr·Me 2S in a 2:1 ratio in the presence of ZnI2 afforded the product with high regioselectivity (99a€‰%) and in good yield (91a€‰%). The allylic substitution of exocyclic allylic picolinates (n = 1, 2; R = Ph(CH2)2, iPr, Ph) with a ArCu(acac)MgBr reagent (Ar = Ph, p-tolyl, p-MeOC6H4, p-FC6H4, o-tolyl, o-MeOC6H4) that was derived from a 2:1 ratio of ArMgBr and Cu(acac)2 efficiently afforded the anti-SN2' products in terms of regioselectivity (95-99a€‰%), chirality transfer (91-99a€‰%), and yield (71-91a€‰%). Copyright
Enantioselective route to ketones and lactones from exocyclic allylic alcohols via metal and enzyme catalysis
Warner, Madeleine C.,Nagendiran, Anuja,Bogár, Krisztián,B?ckvall, Jan-E.
supporting information, p. 5094 - 5097 (2013/01/15)
A general and efficient route for the synthesis of enantiomerically pure α-substituted ketones and the corresponding lactones has been developed. Ruthenium- and enzyme-catalyzed dynamic kinetic resolution (DKR) with a subsequent Cu-catalyzed α-allylic substitution are the key steps of the route. The α-substituted ketones were obtained in high yields and with excellent enantiomeric excess. The methodology was applied to the synthesis of a naturally occurring caprolactone, (R)-10-methyl-6-undecanolide, via a subsequent Baeyer-Villiger oxidation.
The palladium-catalyzed aerobic kinetic resolution of secondary alcohols: Reaction development, scope, and applications
Ebner, David C.,Bagdanoff, Jeffrey T.,Ferreira, Eric M.,McFadden, Ryan M.,Caspi, Daniel D.,Trend, Raissa M.,Stoltz, Brian M.
supporting information; experimental part, p. 12978 - 12992 (2010/06/19)
The first palladium-catalyzed enantioselective oxidation of secondary alcohols has been developed, utilizing the readily available diamine (-)-sparteine as a chiral ligand and molecular oxygen as the stoichiometric oxidant. Mechanistic insights regarding the role of the base and hydrogen-bond donors have resulted in several improvements to the original system. Namely, addition of cesium carbonate and tert-butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23°C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kinetic resolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good-toexcellent selectivity factors. This catalyst system has also been applied to the desymmetrization of meso-diols, providing high yields of enantioenriched hydroxyketones.
Chemoenzymatic dynamic kinetic resolution of allylic alcohols: A highly enantioselective route to acyloin acetates
Bogar, Krisztian,Vidal, Pilar Hoyos,Alcantara Leon, Andres R.,Baeckvall, Jan-E.
, p. 3401 - 3404 (2008/02/12)
Dynamic kinetic resolution (DKR) of a series of sterically hindered allylic alcohols has been conducted with Candida antarctica lipase B (CALB) and ruthenium catalyst 1. The optically pure allylic acetates obtained were subjected to oxidative cleavage to
One-pot synthesis and resolution of chiral allylic alcohols
Kamal, Ahmed,Sandbhor, Mahendra,Shaik, Ahmad Ali,Sravanthi
, p. 2839 - 2844 (2007/10/03)
Substituted α,β-unsaturated ketones were selectively reduced to the corresponding allylic alcohols under mild reaction conditions. The allylic alcohols thus obtained were kinetically resolved by lipase catalyzed transesterification in the same pot to affo
Stereoselective hydrogen transfer reactions of vinyl radicals: Cyclization of alkynyl iodides by unimolecular chain transfer from silicon hydrides
Martinez-Grau, Angeles,Curran, Dennis P.
, p. 5679 - 5698 (2007/10/03)
The cyclization of several substituted hexynyl and heptynyl iodides proceeds stereoselectively to give either E- or Z-exocyclic double bonds depending on the type of precursor and radical chain used, In UniMolecular Chain Transfer (UMCT) reactions, the intramolecular abstraction of hydrogen by the intermediate vinyl radical leads exclusively to the E-isomer while the traditional tin hydride method usually provides the Z-isomer with good selectivity.
Intramolecular reductive cyclization of aldehydes and ketones with alkynes promoted by samarium(II) iodide
Shim,Hwang,Kang,Chang
, p. 4765 - 4768 (2007/10/02)
Samarium(II) iodide mediated intramolecular reductive coupling of carbonyl groups and alkynes in the presence of HMPA and t-BuOH was successfully performed to provide cyclized products. Some cyclic compounds containing a heteroatom such as oxygen or nitrogen were also efficiently prepared by this coupling reaction.
