64025-65-6Relevant academic research and scientific papers
Iridium-Catalyzed Regioselective Hydroalkynylation of Internal Alkenes Directed by an Oxime
Gao, Peng-Chao,Li, Bi-Jie,Wang, Zi-Xuan
, p. 9500 - 9504 (2021/12/14)
We report here an iridium-catalyzed hydroalkynylation of allylic alcohols protected by an oxime group. Catalytic alkynylation occurs exclusively at the distal position of the alkene. This method generates γ-alkynyl alcohol oximes directly from internal alkenes and terminal alkynes. The oxime group can be readily removed to afford a free alcohol, thus providing an indirect route for the catalytic hydroalkynylation of allylic alcohols.
Catalytic Regio- and Enantioselective Oxytrifluoromethylthiolation of Aliphatic Internal Alkenes by Neighboring Group Assistance
Xu, Jia,Zhang, Yuanyuan,Qin, Tian,Zhao, Xiaodan
supporting information, p. 6384 - 6388 (2018/10/09)
Chiral selenide-catalyzed oxytrifluoromethylthiolation of aliphatic internal alkenes by a formally intermolecular strategy is disclosed, affording CF3S 1,3-amino alcohol and 1,3-diol derivatives with high regio-, enantio-, and diastereoselectivities. The reactions are promoted by a neighboring imide or ester group on substrates via a six-membered ring transition state. This assistance strategy is also successfully applied to the regio- and diastereoselective oxyhalofunctionalization of internal alkenes and the conversion of alkynes.
Chiral Selenide-Catalyzed Enantioselective Construction of Saturated Trifluoromethylthiolated Azaheterocycles
Luo, Jie,Liu, Yannan,Zhao, Xiaodan
, p. 3434 - 3437 (2017/07/15)
An indane-based, bifunctional, chiral selenide catalyst has been developed. The new catalyst is efficient for the enantioselective synthesis of saturated azaheterocycles possessing a trifluoromethylthio group. The desired products were obtained in good yields with high diastereo- and enantioselectivities.
Metal-Free Enantioselective Oxidative Arylation of Alkenes: Hypervalent-Iodine-Promoted Oxidative C?C Bond Formation
Shimogaki, Mio,Fujita, Morifumi,Sugimura, Takashi
, p. 15797 - 15801 (2016/12/16)
The enantioselective oxyarylation of (E)-6-aryl-1-silyloxylhex-3-ene was achieved using a lactate-based chiral hypervalent iodine(III) reagent in the presence of boron trifluoride diethyl etherate. The silyl ether promotes the oxidative cyclization, and enhances the enantioselectivity. In addition, the corresponding aminoarylation was achieved.
Copper-Catalyzed Diastereoselective Synthesis of Trifluoromethylated Tetrahydrofurans
Wang, Yanan,Jiang, Min,Liu, Jin-Tao
supporting information, p. 1322 - 1327 (2016/04/26)
The copper-catalyzed intramolecular diastereoselective trifluoromethylcycloetherification of homoallylic alcohols with Togni's reagent as trifluoromethylating reagent was realized under mild conditions. Various trifluoromethylated tetrahydrofurans were synthesized in moderate to good yields. Moreover, a wide range of common functional groups was tolerated.
Oxidative Prins and Prins/Friedel-Crafts cyclizations for the stereoselective synthesis of dioxabicycles and hexahydro-1H-benzo[f]isochromenes via the benzylic C-H activation
Subba Reddy,Borkar, Prashant,Yadav,Purushotham Reddy,Kunwar,Sridhar,Gree, Rene
supporting information; experimental part, p. 1349 - 1358 (2012/03/27)
1-Benzyl ethers of (E)- and (Z)-hex-3-en-1,6-diols and hept-3-en-1,7-diols undergo a smooth oxidative cyclization with DDQ in the presence of In(OTf) 3 through a sequential C-H bond activation and an intramolecular Prins cyclization to afford t
Tandem Prins/friedel-crafts cyclization for stereoselective synthesis of heterotricyclic systems
Reddy, B.V. Subba,Borkar, Prashant,Yadav,Sridhar,Gree, Rene
supporting information; experimental part, p. 7677 - 7690 (2011/12/02)
Homoallylic substrates such as (E)-6-arylhex-3-enyl alcohols, N-tosylamides, and thiols undergo smooth cross-coupling with various aldehydes in the presence of 10 mol % Sc(OTf)3 and 30 mol % TsOH to afford the trans-fused hexahydro-1H-benzo [f]isochromenes, N-tosyloctahydrobenzo [f] -isoquinolines, and hexahydro-lH-benzo [f]isothiochromenes, respectively. However, the cross-coupling of (Z)-olefins such as 6-arylhex-3-enyl alcohols, N-tosylamides, and thiols with aldehydes affords the corresponding hexahydro-1H-benzo-[f]isochromenes, N-tosyloctahydrobenzo [f]isoquinolines, and hexahydro-1H-benzo[f] isothiochromenes with complete cis selectivity via intramolecular Prins-, aza-Prins-, and thia-Prins/(Figure presented) Friedel - Crafts cyclizations, respectively. Though the Prins cyclization proceeds smoothly under the influence of Sc(OTf)3, high conversions and enhanced reaction rates are achieved using a mixture of Sc(OTf)3 and TsOH (1:3).
Epoxidation of peptidyl olefin isosteres. Stereochemical induction effect of chiral centers at four adjacent C(α) positions
Perlman, Nurit,Livneh, Mordechai,Albeck, Amnon
, p. 1505 - 1516 (2007/10/03)
Four tripeptidyl olefin isosteres were prepared, each of which contains a single chiral center derived from the bulky amino acid phenylalanine at positions corresponding to the P2-P'2 positions of a protease substrate. The effect of these chiral centers on the stereochemical outcome of mCPBA epoxidation of the olefin functionality was studied. A chiral center at P2 or P'2 position has no significant effect, and the P'1 position exerts a small stereoselectivity. A chiral center at the P1 position, on the other hand, has a profound chiral induction effect on the epoxidation reaction. (C) 2000 Elsevier Science Ltd.
