- Selective Isomerization via Transient Thermodynamic Control: Dynamic Epimerization of trans to cis Diols
-
Traditional approaches to stereoselective synthesis require high levels of enantio- and diastereocontrol in every step that forms a new stereocenter. Here, we report an alternative approach, in which the stereochemistry of organic substrates is selectivel
- Macmillan, David W. C.,Oswood, Christian J.
-
supporting information
p. 93 - 98
(2022/01/03)
-
- Chemoselective formation of cyclo-aliphatic and cyclo-olefinic 1,3-diolsviapressure hydrogenation of potentially biobased platform molecules using Kn?lker-type catalysts
-
The hydrogenative conversions of the biobased platform molecules 4-hydroxycyclopent-2-enone and cyclopentane-1,3-dione to their corresponding 1,3-diols are established using a pre-activated Kn?lker-type iron catalyst. The catalyst exhibits a high selectivity for ketone reduction, and does not induce dehydration. Moreover, by using different substituents of the ligand, thecis-transratio of the products can be affected substantially. A decent compatibility of this catalytic system with various structurally related substrates is demonstrated.
- Alsters, Paul L.,Chou, Khi Chhay,De Wildeman, Stefaan M. A.,Faber, Teresa,Hadavi, Darya,Han, Peiliang,Quaedflieg, Peter J. L. M.,Schwalb Freire, Alfonso J.,Verzijl, Gerard K. M.,van Slagmaat, Christian A. M. R.
-
supporting information
p. 10102 - 10112
(2021/08/03)
-
- Acylative desymmetrization of cyclic meso-1,3-diols by chiral DMAP derivatives
-
An efficient enantioselective acylative desymmetrization of cyclic meso-1,3-diols was developed by using a chiral DMAP derivative 1e having a 1,1¤-binaphthyl unit. The reactions required only 0.5mol% of the catalyst and showed good to excellent enantioselectivity. With this transformation, 5a, a key building block for the synthesis of natural products, was easily obtained in almost enantiomerically pure form after a single recrystallization. Control experiments revealed that tert-alcohol units on the catalyst were responsible for both the catalytic activity and enantioselectivity.
- Mandai, Hiroki,Hironaka, Tsubasa,Mitsudo, Koichi,Suga, Seiji
-
supporting information
p. 471 - 474
(2021/03/15)
-
- Catalytic 1,3-difunctionalisation of organic backbones through a highly stereoselective, one-pot, boron conjugate-addition/reduction/oxidation process
-
A simple one-pot, three-step synthetic route to chiral 1,3-amino alcohols and 1,3-diols has been established. Considering the overall stereocontrol of the synthetic protocol, the first and key step is an enantioselective β-boration of α,β-unsaturated imin
- Sole, Cristina,Tatla, Amolak,Mata, Jose A.,Whiting, Andrew,Gulyas, Henrik,Fernandez, Elena
-
supporting information; experimental part
p. 14248 - 14257
(2012/01/19)
-
- Efficient and Practical Arene Hydrogenation by Heterogeneous Catalysts under Mild Conditions
-
An efficient and practical arene hydrogenation procedure based on the use of heterogeneous platinum group catalysts has been developed. Rh/C is the most effective catalyst for the hydrogenation of the aromatic ring, which can be conducted in iPrOH under neutral conditions and at ordinary to medium H 2 pressures (10 atm). A variety of arenes such as alkylbenzenes, benzoic acids, pyridines, furans, are hydrogenated to the corresponding cyclohexyl and heterocyclic compounds in good to excellet yields. The use of Ru/C, less expensive than Rh/C, affords an effective and practical method for the hydrogenation of arenes including phenols. Both catalysts can be reused several times after simple filtration without any significant loss of catalytic activity.
- Maegawa, Tomohiro,Akashi, Akira,Yaguchi, Kiichiro,Iwasaki, Yohei,Shigetsura, Masahiro,Monguchi, Yasunari,Sajiki, Hironao
-
experimental part
p. 6953 - 6963
(2010/02/28)
-
- Enzymatic resolution, desymmetrization, and dynamic kinetic asymmetric transformation of 1,3-cycloalkanediols
-
An efficient desymmetrization of cis-1,3-cyclohexanediol to (1S,3R)-3-(acetoxy)-1-cyclohexanol ((R,S)-2a) was performed via Candida antarctica lipase B (CALB)-catalyzed transesterification, in high yield (up to 93%) and excellent enantioselectivity (ee's
- Fransson, Ann-Britt L.,Xu, Yongmei,Leijondahl, Karin,Baeckvall, Jan-E.
-
p. 6309 - 6316
(2007/10/03)
-
- Pathways of liquid-phase oxidation of cyclohexanol
-
The kinetics of product accumulation in uncatalyzed oxidation of cyclohexanol at 403 K was studied. Along with the compounds originating from oxidation of cyclohexanol at position 1 (cyclohexanone, hydrogen peroxide, 1-hydroxycyclohexyl hydroperoxide), products formed by oxidation of C-H bonds at positions 2-4 were detected: 2-, 3-, and 4-hydroxycyclohexyl hydroperoxides (cis and trans isomers), 1,2-, 1,3-, and 1,4-dihydroxycyclohexanes (cis and trans isomers), 2- and 4-hydroxycyclohexanones, and 2-cyclohexenone.
- Puchkov,Buneeva,Perkel'
-
p. 248 - 253
(2007/10/03)
-
- Conformational Analysis. Part 21. Conformational Isomerism in cis-Cyclohexane-1,3-diol
-
cis-Cyclohexane-1,3-diol (CHD) has been isolated from a cis/trans isomeric mixture by first synthesizing the cyclic acetal 2,4-dioxabicyclononane (D).The 1H NMR spectra of CHD, D, cis- and trans-4-tert-butylcyclohexanol and tert-butylcyclohexane ar
- Abraham, Raymond J.,Chambers, Eric J.,Thomas, W. Anthony
-
p. 1061 - 1066
(2007/10/02)
-
- Rhodium(I)- and iridium(I)-catalyzed hydroboration reactions: Scope and synthetic applications
-
A study of the rhodium(I)- and iridium(I)-catalyzed hydroboration of olefins with catecholborane is described. Applications to organic synthesis were one focus of this investigation. The scope of the reaction was defined, and issues of stereoselection were addressed. The rhodium-catalyzed hydroboration of several classes of allylic alcohols was found to be highly diastereoselective, preferentially affording the isomer complementary to that furnished by the uncatalyzed variant of the reaction (9-BBN). The first two general approaches to effecting a directed olefin hydroboration were developed. Both phosphinites and amides proved capable of delivering the transition metal reagent.
- Evans, David A.,Fu, Gregory C.,Hoveyda, Amir H.
-
p. 6671 - 6679
(2007/10/02)
-
- Enantioselective synthesis of (1S,3S,5R)-1-acetoxy-5-benzyl-oxycyclohexan-3-ol and its application to the synthesis of compactin lactone moiety and quinic acid
-
Porcine liver esterase (PLE)-catalyzed asymmetric hydrolysis of meso-1,3-cis,3,5-cis-1,3-diacetoxy-5-benzyloxycyclohexane 1 afforded (1S,3S,5R)-2 of 87% e.e. Starting from this compound, compactin lactone moiety 17A and its C-6 diastereomer 17B were diast
- Suemune,Matsuno,Uchida,Sakai
-
p. 297 - 306
(2007/10/02)
-