135094-36-9Relevant academic research and scientific papers
Evaluation of the chiral DIANANE backbone as ligand for organolithium reagents
Praz, Jezabel,Guenee, Laure,Aziz, Sarwar,Berkessel, Albrecht,Alexakis, Alexandre
scheme or table, p. 1780 - 1790 (2012/07/28)
Novel endo,endo-2,5-diaminonorbonane-derived tertiary C2- symmetrical diamines were synthesized via the one-pot reductive amination of enantiomerically pure norbornane-2,5-dione. These ligands were applied to various catalytic reactions such as asymmetric deprotonation, asymmetric bromine-lithium exchange, and enantioselective addition of aryl- and allkylithium reagents to aromatic aldimines. Copyright
Some new C2-symmetric bicyclo[2.2.1]heptadiene ligands: synthesis and catalytic activity in rhodium(I)-catalyzed asymmetric 1,4- and 1,2-additions
No?l, Timothy,Vandyck, Koen,Van der Eycken, Johan
, p. 12961 - 12967 (2008/03/17)
C2-Symmetric bicyclo[2.2.1]hepta-2,5-dienes with various substituents (R=Bn, i-Bu, c-Hex, allyl) are prepared starting from the corresponding enantiomerically pure bis-triflate (R=OTf). These chiral ligands are tested and compared in rhodium(I)
Enantioselective Synthesis of DIANANE, a Novel C2-Symmetric Chiral Diamine for Asymmetric Catalysis
Berkessel, Albrecht,Schroeder, Michael,Sklorz, Christoph A.,Tabanella, Stefania,Vogl, Nadine,Lex, Johann,Neudoerfl, Joerg M.
, p. 3050 - 3056 (2007/10/03)
DIANANE (endo,endo-2,5-diaminonorbornane) is a novel chiral C 2-symmetric diamine, based on the rigid bicyclo[2.2.1]heptane scaffold. Schiff-base ligands derived from DIANANE have already found use in asymmetric catalysis, e.g., in the highly e
Experiments towards the formation of 1,6-dehydroquadricyclane and density functional calculations on this and related molecules
Glueck-Walther, Susanne,Jarosch, Oliver,Szeimies, Guenter
, p. 493 - 500 (2007/10/03)
1,6-Dibromoquadricyclane (6) was obtained from norbornadiene (11) by hydroboration, oxidation of the diol 12 to the diketone 14 and its conversion into 2,6-dibromonorbornadiene (20) using tribromodioxaphosphole 16b followed by treatment of the mixture 17/18 with potassium tert-butoxide in DMSO and photocyclization of 20. Reaction of 6 with tBuLi (2 equiv.) led to the formation of 1-bromo-6-lithioquadricyclane 7, the NMR spectra of which were observed up to 0°C. 7 did not lose LiBr to give 4, but could be trapped with H2O and chlorotrimethylsilane to give 21e (53%) and 21f (64%). Reaction of 6 with fBuLi (> 4 equiv.) gave rise to 1,6-dilithioquadricyclane (21c), whose NMR spectra could also be recorded. 21c was converted into the corresponding 1,6-disubstituted quadricyclanes with D2O (87%), chlorotrimethylsilane (92%), dimethyl sulfate (55%), methyl chloroformate (45%), iodine monochloride (62%), and p-toluenesulfonyl chloride (48%). - Density functional calculations using the B3LYP/6-31G* level of theory showed that 1,6-dehydroquadricyclane (4) is a local energy minimum in its singlet electronic state. 4 contains a unique structure with 4 condensed cyclopropane units. The parent hydrocarbons 27 and 28, hitherto unknown, are also local energy minima in their singlet electronic states.
Syntheses in the isocamphane series XLII [1]. Synthesis and odour of 5-exo-hydroxycamphene (isonojigiku alcohol)
Buchbauer, Gerhard,Spreitzer, Helmut,Koller, Ursula,Bauer, Irmtraud,Wachter, Andreas
, p. 865 - 870 (2007/10/03)
The synthesis of the title compound is described. Hydroxylation of the endocyclic double bond of 2-acetyl-3,3-dimethylnorborn-5-ene furnished a mixture of nojigiku alcohol and the title compound. A shorter route leads from 2,5-norbornadiene solely to the desired camphoraceous smelling new hydroxy derivative to which the name isonojigiku alcohol is assigned.
Enzymatic Baeyer-Villiger oxidations of some bicycloheptan-2-ones using monooxygenases from Pseudomonas putida NCIMB 10007: enantioselective preparation of a precursor of azadirachtin
Gagnon, Rene,Grogan, Gideon,Roberts, Stanley M.,Villa, Raffaella,Willetts, Andrew J.
, p. 1505 - 1512 (2007/10/02)
Two monooxygenases MO1 (NADH dependent) and MO2 (NADPH dependent) isolated from Ps. putida NCIMB 10007 have been utilized as biocatalysts in Baeyer-Villiger oxidations.The former enzyme oxidized the racemic ketones 9, 10 and 14 into
New Ligands with a Wide Bite Angle. Efficient Catalytic Activity in the Rh(I)-Catalyzed Hydroformylation of Olefins
Yamamoto, Keiji,Momose, Satoru,Funahashi, Masakazu,Ebata, Satoshi,Ohmura, Hideaki,et al.
, p. 189 - 192 (2007/10/02)
The relevance of a new diphosphinite, which holds a natural bite angle around 120 deg in a catalyst complex, to the Rh(I)-catalyzed hydroformylation of certain olefins is examined, exhibiting a high turnover frequency (TOF) as compared with a typical 1,2-bis(diphenylphosphino)ethane with a bite angle around 85 deg.
Lipase YS-Catalyzed Enantioselective Transesterification of Alcohols of Bicarbocyclic Compounds
Naemura, Koichiro,Ida, Hirotsugu,Fukuda, Ritsuko
, p. 573 - 577 (2007/10/02)
Lipase YS-catalyzed enantioselective acylations of (1RS,2RS,4RS,5RS)-bicycloheptane-2,5-diol, (1RS,2RS,4RS,5SR)-bicyclooctane-2,5-diol, (1RS,2RS,4RS,5RS)-bicyclooctane-2,5-diol, and (1RS,2SR,5RS,6SR)-bicyclononane-2,6-diol with aryl acetates such as phenyl acetate, 1-naphthyl acetate, and 2-naphthyl acetate gave the monoacetates and the diols in optically active forms.The optical purities of (+)-(2R,5R)-2-acetoxybicycloheptan-5-ol, (-)-(1S,2R,4S,5R)-2-acetoxybicyclooctan-5-ol, and (+)-(2R,6R)-2-acetoxybicyclononan-6-ol obtained using phenyl acetate were higher than those of the monoacetates which have been resolved by PLE-catalyzed hydrolysis of the corresponding racemic diacetates.Enzymic acylations of the diols using phenyl esters such as phenyl propanoate, phenyl butanoate, and phenyl octanoate as acylating agents gave the corresponding monoesters, which showed nearly the same enantiomeric excess value as the acetates.A simple model for predicting which enantiomer of racemic alcohols is acylated preferentially by lipase YS-catalyzed enantioselective transesterification is proposed on the basis of the results obtained here.
Enantioselective Hydroboration Mediated by Homochiral Rhodium Catalysts
Burgess, Kevin,Ohlmeyer, Michael J.
, p. 5178 - 5179 (2007/10/02)
Homochiral rhodium-phosphine complexes facilitate enantioselective hydroboration of alkenes by catecholborane; oxidation of the products affords optically active alcohols.
Nucleophilic Exchange Reactions at 1-Chloroquadricyclane: 1,5- and 1,7-Dehydroquadricyclane as Reactive Intermediates.
Baumgaertel, Otto,Szeimies, Guenter
, p. 2180 - 2204 (2007/10/02)
Quadricyclane was metalated at position 1 to 1b in high yield by the complex of butyllithium and tetramethylethylenediamine or by a mixture of butyllithium and potassium tert-butoxide.Numerous 1-substituted quadricyclanes were accessible via 1b.Nuclophilic substitution products were obtained by the reaction of 1-chloroquadricyclane with organolithium compounds, lithium amides, and with lithium ethylthiolate (in the presence of a bulky strong base), which could be isomerized to the corresponding norbornadienes.Mechanistic investigations have shown that 1,7- and 1,5-dehydroquadricyclane (4 and 5) were involved as reactive intermediates.The nucleophilic substitution of optical active 1-chloroquadricyclane with lithium dimethylamide proceeded with 96percent racemization.This result is in accord with an elimination-addition mechanism passing over 4 and 5.
