80582-76-9Relevant academic research and scientific papers
Hydrogen Bonding-Assisted Enhancement of the Reaction Rate and Selectivity in the Kinetic Resolution of d,l-1,2-Diols with Chiral Nucleophilic Catalysts
Fujii, Kazuki,Mitsudo, Koichi,Mandai, Hiroki,Suga, Seiji
supporting information, p. 2778 - 2788 (2017/08/23)
An extremely efficient acylative kinetic resolution of d,l-1,2-diols in the presence of only 0.5 mol% of binaphthyl-based chiral N,N-4-dimethylaminopyridine was developed (selectivity factor of up to 180). Several key experiments revealed that hydrogen bonding between the tert-alcohol unit(s) of the catalyst and the 1,2-diol unit of the substrate is critical for accelerating the rate of monoacylation and achieving high enantioselectivity. This catalytic system can be applied to a wide range of substrates involving racemic acyclic and cyclic 1,2-diols with high selectivity factors. The kinetic resolution of d,l-hydrobenzoin and trans-1,2-cyclohexanediol on a multigram scale (10 g) also proceeded with high selectivity and under moderate reaction conditions: (i) very low catalyst loading (0.1 mol%); (ii) an easily achievable low reaction temperature (0 °C); (iii) high substrate concentration (1.0 M); and (iv) short reaction time (30 min). (Figure presented.).
Synthesis of saturated benzodioxepinone analogues: Insight into the importance of the aromatic ring binding motif for marine odorants
Plummer, Christopher M.,Gericke, Robert,Kraft, Philip,Raynor, Aaron,Froese, Jordan,Hudlick, Tom,Rook, Trevor J.,Jones, Oliver A. H.,Hügel, Helmut M.
, p. 486 - 495 (2015/01/30)
As part of our research exploring the influence of molecular variations of Calone 1951 on marine fragrance performance, we report the synthesis, crystal structures, and olfactory analysis of the first saturated benzodioxepinone analogues. By su
A broadly applicable and practical oligomeric (salen)Co catalyst for enantioselective epoxide ring-opening reactions
White, David E.,Tadross, Pamela M.,Lu, Zhe,Jacobsen, Eric N.
supporting information, p. 4165 - 4180 (2014/06/09)
The (salen)Co catalyst (4a) can be prepared as a mixture of cyclic oligomers in a short, chromatography-free synthesis from inexpensive, commercially available precursors. This catalyst displays remarkable enhancements in reactivity and enantioselectivity relative to monomeric and other multimeric (salen)Co catalysts in a wide variety of enantioselective epoxide ring-opening reactions. The application of catalyst 4a is illustrated in the kinetic resolution of terminal epoxides by nucleophilic ring-opening with water, phenols, and primary alcohols; the desymmetrization of meso epoxides by addition of water and carbamates; and the desymmetrization of oxetanes by intramolecular ring opening with alcohols and phenols. The favorable solubility properties of complex 4a under the catalytic conditions facilitated mechanistic studies, allowing elucidation of the basis for the beneficial effect of oligomerization. Finally, a catalyst selection guide is provided to delineate the specific advantages of oligomeric catalyst 4a relative to (salen)Co monomer 1 for each reaction class.
Enhanced rate and selectivity by carboxylate salt as a basic cocatalyst in chiral N-heterocyclic carbene-catalyzed asymmetric acylation of secondary alcohols
Kuwano, Satoru,Harada, Shingo,Kang, Bubwoong,Oriez, Raphael,Yamaoka, Yousuke,Takasu, Kiyosei,Yamada, Ken-Ichi
supporting information, p. 11485 - 11488 (2013/09/02)
The rate and enantioselectivity of chiral NHC-catalyzed asymmetric acylation of alcohols with an adjacent H-bond donor functionality are remarkably enhanced in the presence of a carboxylate cocatalyst. The degree of the enhancement is correlated with the basicity of the carboxylate. With a cocatalyst and a newly developed electron-deficient chiral NHC, kinetic resolution and desymmetrization of cyclic diols and amino alcohols were achieved with extremely high selectivity (up to s = 218 and 99% ee, respectively) at a low catalyst loading (0.5 mol %). This asymmetric acylation is characterized by a unique preference for alcohols over amines, which are not converted into amides under the reaction conditions.
Catalytic asymmetric synthesis of butane diacetal-protected (4S,5S)-dihydroxycyclohexen-1-one and use in natural product synthesis
Burns, David J.,Hachisu, Shuji,O'Brien, Peter,Taylor, Richard J. K.
supporting information, p. 7666 - 7668 (2013/05/08)
Due to the lack of availability of unnatural (+)-quinic acid as a starting material, a 6-step synthesis of butane diacetal-protected (4S,5S)- dihydroxycyclohexen-1-one (formally derived from (+)-quinic acid) has been devised. The key catalytic asymmetric
Regioselective cyclopolymerization of 1,7-octadiynes
Naumann, Stefan,Unold, Joerg,Frey, Wolfgang,Buchmeiser, Michael R.
scheme or table, p. 8380 - 8387 (2012/03/11)
The regioselective cyclopolymerization of two structurally different 1,7-octadiynes, i.e. of 1,4-dihexyloxy-2,3-dipropargylbenzene (M1) and (R,R)/(S,S)-4,5-bis(trimethylsilyloxy)-1,7-octadiyne (M2) has been achieved with the modified Grubbs-Hoveyda-type metathesis initiator Ru(NCO) 2(IMesH2)(=CH-(2-(2-PrO)C6H4)) (I1, IMesH2 = 1,3-dimesitylimidazolidin-2-ylidene) and with a series of Schrock initiators in the presence of quinuclidine, yielding conjugated polymers consisting virtually exclusively of 1,2-cyclohex-1-enylenvinylene units. In contrast to I1, Mo(N-2,6-(2-Pr)2C6H3) (CHCMe2Ph)(OCHMe2)2 (I3) allows for establishing a living polymerization with M2 in the presence of quinuclidine. The structure of the polymers, which represent highly soluble and stable poly(acetylene) analogues, was confirmed by comparing the 13C NMR shifts of model compounds with those of the corresponding polymer. Poly(ene)s that are virtually solely based on six-membered repeat units show a bathochromic shift in UV-absorption compared to poly(ene)s based on six- and seven-membered rings.
Epoxide hydrolase-catalyzed enantioselective synthesis of chiral 1,2-diols via desymmetrization of meso-epoxides
Zhao, Lishan,Han, Bin,Huang, Zilin,Miller, Mark,Huang, Hongjun,Malashock, Dan S.,Zhu, Zuolin,Milan, Aileen,Robertson, Dan E.,Weiner, David P.,Burk, Mark J.
, p. 11156 - 11157 (2007/10/03)
The discovery, from nature, of a diverse set of microbial epoxide hydrolases is reported. The utility of a library of epoxide hydrolases in the synthesis of chiral 1,2-diols via desymmetrization of a wide range of meso-epoxides, including cyclic as well as acyclic alkyl- and aryl-substituted substrates, is demonstrated. The chiral (R,R)-diols were furnished with high ee's and yields. The discovery of the first microbial epoxide hydrolases providing access to complementary (S,S)-diols is also described. Copyright
A practical synthesis of the F-ring of halichondrin B via ozonolytic desymmetrization of a C2-symmetric dihydroxycyclohexene
Jiang, Lei,Martinelli, Joseph R.,Burke, Steven D.
, p. 1150 - 1153 (2007/10/03)
C2-symmetric dihydroxycyclohexene 1 was desymmetrized via a one-pot Criegee ozonolysis/acylation protocol to afford acetal-lactone 2. Installation of the allyl side chain on the convex face of the bicyclic system and subsequent reduction provided the desired tetrahydrofuran 4 with the correct relative and absolute stereochemistries. Simple functional group manipulations led to the desired F-ring module 3 of halichondrin B.
One-Pot and Stereospecific Synthesis of cis-1,2-Diazides via Mitsunobu Reaction of Epoxides
Goeksu, Sueleyman,Secen, Hasan,Suetbeyaz, Yasar
, p. 2373 - 2378 (2007/10/03)
Mitsunobu reaction of epoxides using hydrazoic acid, diethylazodicarboxylate, and triphenylphosphine as reagents gave the corresponding cis-1,2-diazides in moderate yield. Application of similar reaction conditions to trans-diols furnished the corresponding trans-1,2-diazides.
A new facile preparation of a bifunctionalized C6 homologating agent from 1,4-cyclohexadiene
Michaud, Sabine,Viala, Jacques
, p. 3019 - 3024 (2007/10/03)
a new preparation of the bifunctionalized unsaturated C6 homologating agent 2b which is an efficient synthetic tool is described. This method is atom economic, very efficient on grams scale and easy to handle from cheap commercially available 1,4-cyclohexadiene. Synthetic applications by using a mild and selective monohydrolysis of acetal catalyzed by FeCl3 are described.
