63830-81-9Relevant academic research and scientific papers
A de Novo Synthetic Route to 1,2,3,4-Tetrahydroisoquinoline Derivatives
ábrahámi, Renáta A.,Fustero, Santos,Fül?p, Ferenc,Kiss, Loránd
, p. 2066 - 2070 (2018/03/29)
A novel synthetic approach was developed for the construction of the 1,2,3,4-tetrahydroisoquinoline framework possessing varied functions. The synthetic strategy was based on oxidative ring opening of some indene derivatives through their C=C bond, followed by double reductive amination of the dicarbonyl intermediates with various primary alkyl- or fluoroalkylamines.
Bioinspired Total Synthesis of (±)-Chaetophenol C Enabled by a Pd-Catalyzed Cascade Cyclization
Li, Yun,Zhang, Qingyu,Wang, Hongyu,Cheng, Bin,Zhai, Hongbin
supporting information, p. 4387 - 4390 (2017/08/23)
A novel Pd(II)-catalyzed cascade reaction has been developed that consists of a highly regio- and stereoselective oxa [4 + 2] cycloaddition reaction of o-alkynylbenzaldehydes and an intramolecular carboxylic group quenching of the in situ generated oxonium ion. This new reaction provides a one-step construction of the tetracyclic core structure of chaetophenol C from two simple starting materials. The developed chemistry was successfully applied to the first total synthesis of chaetophenol C and dozens of its analogues.
Activated iodosylbenzene monomer as an ozone equivalent: Oxidative cleavage of carbon-carbon double bonds in the presence of water
Miyamoto, Kazunori,Tada, Norihiro,Ochiai, Masahito
, p. 2772 - 2773 (2007/10/03)
Reported here for the first time are the developments of an efficient method for oxidative cleavage of carbon-carbon double bonds yielding carbonyl compounds by using aryl-λ3-iodanes, which involve a combination of iodosylbenzene and HBF4 in the presence of water. The method serves as a safety alternative to ozonolysis. The oxidative cleavage of olefins probably involves the hitherto unknown direct vicinal dihydroxylations of double bonds with aryl-λ3-iodanes and the subsequent oxidative glycol fissions. Cyclic (cyclopentenes, cyclohexenes, etc.) and acyclic olefins are cleaved smoothly under our conditions. In the reaction of electron-deficient styrenes such as m-nitrostyrene, intermediate formation of the corresponding epoxide was detected. A variety of aryloxiranes also undergo an oxidative cleavage of the epoxide rings under our conditions, and aromatic aldehydes were obtained in good yields. Copyright
Enantioselective formation of quaternary stereocenters using the catalytic intramolecular Stetter reaction
Moore, Jennifer L.,Kerr, Mark S.,Rovis, Tomislav
, p. 11477 - 11482 (2007/10/03)
Asymmetric formation of quaternary stereocenters has been accomplished using the catalytic intramolecular Stetter reaction. A?variety of tethered aldehydes and Michael acceptors are cyclized in excellent yields and enantioselectivities.
Thiazol-2-ylidene catalysis in intramolecular crossed aldehyde-ketone benzoin reactions
Enders, Dieter,Niemeier, Oliver
, p. 2111 - 2114 (2007/10/03)
Intramolecular crossed aldehyde-ketone benzoin-type reactions catalyzed by nucleophilic carbenes, easily generated from commercially available thiazolium salts as precatalysts, are described. Five- and six-membered cyclic acyloins are obtained in moderate to good yields. Depending on the structure of the aldehyde-ketone substrate, an interchange of the alcohol and ketone function of the resulting acyloin is possible. Simple aldehyde-ketones are not good substrates due to the competing intermolecular reaction. Starting from biphenyl-2,2′-dicarbaldehyde, the intermediate acyloin is converted to 9,10-phenanthrenequinone by mild air oxidation.
Mechanistic imperatives for catalysis of aldol addition reactions: Partitioning of the enolate intermediate between reaction with bronsted acids and the carbonyl group
Richard, John P.,Nagorski
, p. 4763 - 4770 (2007/10/03)
The lyoxide ion catalyzed intramolecular aldol addition reaction of 2- (2-oxopropyl)benzaldehyde (1) to give the aldol adduct 3 proceeds via essentially irreversible formation of the acetone-like enolate intermediate 2, because reprotonation of 2 by a solvent of H2O or D2O (k(HOH) or k(DOD)) is much slower than intramolecular addition of the enolate to the carbonyl group (k(c)). The aldol addition reaction of 1 catalyzed by high concentrations of 3-substituted quinuclidine buffers proceeds via reversible deprotonation of 1 to give the enolate 2, and rate-determining addition of the enolate to the carbonyl group. A rate constant ratio of k(c)/k(HOH) = 35 was determined for partitioning of the enolate 2 between intramolecular addition to the carbonyl group and protonation by solvent water. The corresponding ratios k(BH)/k(c) (M-1) for the protonation of 2 by Bronsted buffer acids and intramolecular aldol addition increase from 7 to 450 as the acidity of the buffer acid is increased from pK(BH) = 11.5 to 7.5. The data show that the electrophilic reactivity of the benzaldehyde carbonyl group toward intramolecular addition of the enolate 2 is the same as that of a hypothetical tertiary ammonium cation of pK(BH) = 13.3. The Marcus intrinsic barrier for addition of the enolate 2 to the carbonyl group is unexpectedly small, which suggests that the transition state for this reaction is stabilized by interactions between the soft-soft acid-base pair. The relevance of this work to chemical and enzymatic catalysis of aldol condensation reactions is discussed.
THERMOLYTIC RING OPENING OF ACYLOXYBENZOCYCLOBUTENES: AN EFFICIENT ROUTE TO 3-SUBSTITUTED ISOQUINOLINES
Schiess, Peter,Huys-Francotte, Martine,Vogel, Caspar
, p. 3959 - 3962 (2007/10/02)
Upon flash vacuum pyrolysis acyloxybenzocyclobutenes 4 rearrange through an intramolecular 1,5-acyl shift to 2-formylbenzyl ketones 6 which can be converted to 3-substituted isoquinolines 7.
