107243-99-2Relevant articles and documents
C(10)-substituted camphors and fenchones by electrophilic treatment of 2-methylenenorbornan-1-ols: Enantiospecificity, scope, and limitations
De la Moya Cerero, Santiago,Martinez, Antonio Garcia,Vilar, Enrique Teso,Fraile, Amelia Garcia,Maroto, Beatriz Lora
, p. 1451 - 1458 (2003)
Valuable chiral sources of C(10)-substituted camphors and C(10)-substituted fenchones can be straightforwardly obtained by treatment of an appropriate, easily obtainable, camphor- or fenchonederived 2-methylenenorbornan-1-ol with an electrophilic reagent. The process takes place via a tandem regioselective carbon-carbon double-bond addition/stereocontrolled Wagner-Meerwein rearrangement. A complete study of the enantiospecificity, scope, and limitations of this process, as well as about the role played by the hydroxyl group attached at the C(1) bridgehead position of the starting 2-methylenenorbornan-1-ols, has been realized. The feasibility of the described methodology has been exemplified by the highly efficient enantiospecific preparation of several interesting C(10)-halogen-, C(10)-O-, C(10)-S-, C(10)-Se-, or C(10)-C-substituted camphors and fenchones.
Scalable C-H Oxidation with Copper: Synthesis of Polyoxypregnanes
See, Yi Yang,Herrmann, Aaron T.,Aihara, Yoshinori,Baran, Phil S.
, p. 13776 - 13779 (2015)
Steroids bearing C12 oxidations are widespread in nature, yet only one preparative chemical method addresses this challenge in a low-yielding and not fully understood fashion: Sch?necker's Cu-mediated oxidation. This work shines new light onto this powerf
A new straightforward preparation of enantiopure 10-hydroxycamphor
Garcia Martinez, Antonio,Teso Vilar, Enrique,Garcia Fraile, Amelia,De La Moya Cerero, Santiago,Lora Maroto, Beatriz
, p. 4437 - 4440 (2000)
The enantiospecific preparation of the interesting chiral source 10-hydroxycamphor from commercially available camphor is described. The synthetic procedure takes place straightforwardly in only three synthetic steps with a high overall yield. The key step of the described route is based on the ability of a 2-methylenenorbornane intermediate to undergo an enantiospecific Wagner-Meerwein rearrangement under electrophilic treatment with m-CPBA.
Intramolecular γ-hydroxylations of nonactivated C-H bonds with copper complexes and molecular oxygen
Schoenecker, Bruno,Zheldakova, Tatjana,Lange, Corinna,Guenther, Wolfgang,Goerls, Helmar,Bohl, Martin
, p. 6029 - 6042 (2004)
Copper(I) complexes incorporating the isomeric bidentate ligands IMPY (iminomethyl-2-pyridines) or AMPY (aminomethylene-2-pyridines) are quite unusual in their ability to bind and activate molecular oxygen. Using these complexes, hydroxylations of nonactivated CH, CH2, or CH3 groups in the γ-position in relation to the imino-nitrogen atom, and with a specific orientation of one H atom with respect to the binuclear Cu-O species, can be achieved in synthetically useful yields. Through mechanistic studies employing conformationally well-defined molecules (for example, cyclic isoprenoids), coupled with solid-state X-ray structure analyses and force-field calculations, we postulate a seven-membered transition state for this reaction in which six atoms lie approximately in a plane. This plane is defined by the positions of the lone pairs on the nitrogen atoms, as well as the copper and the oxygen atoms. For a successful hydroxylation, one hydrogen atom should be located close to this plane. Prediction of the stereochemical course of these reactions is possible based on a simple geometrical criterion. The convenient introduction of IMPY and AMPY groups as auxiliaries into oxo and primary amino compounds and the simple hydrolysis after the hydroxylation procedure has allowed the synthesis of 3-hydroxy-1-oxo and 3-hydroxy-1-amino compounds. If desired, the 3-hydroxy-1-IMPY and -1-AMPY compounds can be reduced with NaBH4 to obtain 3-hydroxy-1-aminomethylpyridines. For a successful hydroxylation procedure, the method employed for the synthesis of the CuI complexes is very important. Starting either from CuI salts or from CuII salts with a subsequent reduction with benzoin/triethylamine may turn out to be the better way, depending on the ligand and the molecular structure.
Straightforward synthesis of poly(dimethylsiloxane) phases with immobilized (1R)-3-(perfluoroalkanoyl)camphorate metal complexes and their application in enantioselective complexation gas chromatography
Spallek, Markus J.,Storch, Golo,Trapp, Oliver
, p. 3929 - 3945 (2012)
A straightforward synthesis of novel chiral polysiloxane-based metal stationary phases immobilized through a propylenoxy linker (Chirasil-Metal- OC3) to the polymeric backbone is presented. Synthesis was accomplished in six steps with high overall yields starting from commercially available, enantiopure (+)-(1S)-camphorsulfonic acid. Two different approaches towards Chirasil-Metal phases featuring either a propylenoxy or propylenthio linker used for immobilization through hydrosilylation are presented. Furthermore, a new protocol for the fluoroacylation, which is one of the key steps in the synthesis of (1R)-3-(perfluoroalkanoyl)camphorate metal complexes, was developed to improve the isolation and overall yield. The immobilization of (1R,4S)-10-(allyloxy)-3-(heptafluorobutanoyl)camphor -10-(allyloxy)-hfbc -onto polysiloxanes as well as the incorporation of nickel(II), oxovanadium(IV), europium(III), and lanthanum(III) was characterized by FT ATR IR and NMR spectroscopy. Overall, seven different Chirasil-Metal-OC3 polymers with different separation properties were prepared by metal incorporation and variation of the amount of immobilized (1R,4S)-10-(allyloxy)-3- (heptafluorobutanoyl)camphor (10-allyloxy-hfbc: 3.5, 10.2, and 20.0 %). Their performance in enantioselective complexation gas chromatography was systematically studied and excellent enantioselectivity was found for Chirasil-Nickel-OC3. Separation of 29 small-sized compounds, encompassing, among others, epoxides, substituted alkenes and alkynes as well as alcohols and amides, was achieved with high separation factors α. The synthetic strategy, enantiomer separations and thermal stability (up to 160 °C) demonstrates the versatility of the newly derived Chirasil-Metal-OC 3 phases.
Directed Hydroxylation of sp2 and sp3 C-H Bonds Using Stoichiometric Amounts of Cu and H2O2
Trammell, Rachel,D'Amore, Lorenzo,Cordova, Alexandra,Polunin, Pavel,Xie, Nan,Siegler, Maxime A.,Belanzoni, Paola,Swart, Marcel,Garcia-Bosch, Isaac
supporting information, p. 7584 - 7592 (2019/06/11)
The use of copper for C-H bond functionalization, compared to other metals, is relatively unexplored. Herein, we report a synthetic protocol for the regioselective hydroxylation of sp2 and sp3 C-H bonds using a directing group, stoichiometric amounts of Cu and H2O2. A wide array of aromatic ketones and aldehydes are oxidized in the carbonyl γ-position with remarkable yields. We also expanded this methodology to hydroxylate the β-position of alkylic ketones. Spectroscopic characterization, kinetics, and density functional theory calculations point toward the involvement of a mononuclear LCuII(OOH) species, which oxidizes the aromatic sp2 C-H bonds via a concerted heterolytic O-O bond cleavage with concomitant electrophilic attack on the arene system.
Enantioselective addition of organozinc reagents to carbonyl compounds catalyzed by a camphor derived chiral γ-amino thiol ligand
Wu, Hsyueh-Liang,Wu, Ping-Yu,Cheng, Ying-Ni,Uang, Biing-Jiun
, p. 2656 - 2665 (2016/05/10)
In this article, the design and synthesis of the chiral camphor derived γ-amino thiol ligand 17 and its application in catalytic enantioselective carbon-carbon forming reactions through the addition of organozinc reagents to carbonyl compounds is described. The catalytic activity and enantioselectivity of ligand 17 is demonstrated in the enantioselective addition of various organozinc reagents to aldehydes and ketoesters, offering the corresponding alcohols in high yields and enantioselectivities. The role of the mercapto group in the highly enantioselective 1,2-addition reaction of organozincs to aldehyde is also discussed.
