114837-50-2Relevant academic research and scientific papers
Synthesis of C5-allylindoles through an iridium-catalyzed asymmetric allylic substitution/oxidation reaction sequence of N-alkyl indolines
Lu, Jiamin,Xu, Ruigang,Zeng, Haixia,Zhong, Guofu,Wang, Meifang,Ni, Zhigang,Zeng, Xiaofei
supporting information, p. 3426 - 3431 (2021/05/07)
Iridium/Br?nsted acid cooperative catalyzed asymmetric allylic substitution reactions at the C5 position of indolines have been reported for the first time. The highly efficient protocol allows rapid access to various C5-allylated products in good to high
Enantioselective Allylation of Alkenyl Boronates Promotes a 1,2-Metalate Rearrangement with 1,3-Diastereocontrol
Davis, Colton R.,Luvaga, Irungu K.,Ready, Joseph M.
supporting information, p. 4921 - 4927 (2021/05/04)
Alkenyl boronates add to Ir(π-allyl) intermediates with high enantioselectivity. A 1,2-metalate shift forms a second C-C bond and sets a 1,3-stereochemical relationship. The three-component coupling provides tertiary boronic esters that can undergo multiple additional functionalizations. An extension to trisubstituted olefins sets three contiguous stereocenters.
[Pd]-Catalyzedpara-selective allylation of phenols: access to 4-[(E)-3-aryl/alkylprop-2-enyl]phenols
Chinnabattigalla, Sreenivasulu,Choudhury, Aditya,Gedu, Satyanarayana
supporting information, p. 8259 - 8263 (2021/10/12)
4-[(E)-3-Arylprop-2-enyl]phenols are omnipresent scaffolds and constitute natural products and biologically significant compounds. Obtusastyrene and obtustyrene are two such phenolic-based natural products isolated fromDalbergia retusa. The development of strategies based on a site-selective allylation, particularly protecting group-free substrates and non-activated coupling agents, is indispensable in organic synthesis. Herein, we present a highly regioselective [Pd]-catalyzedpara-allylation of phenols using simple, inactivated allylic alcohols as allylating coupling partners. Notably, this strategy is successful in open-air and under mild reaction conditions. Besides, the efficacy of the present protocol was demonstrated by the direct synthesis of obtusastyrene and obtustyrene.
Highly Enantioselective Iridium-Catalyzed Coupling Reaction of Vinyl Azides and Racemic Allylic Carbonates
Han, Min,Yang, Min,Wu, Rui,Li, Yang,Jia, Tao,Gao, Yuanji,Ni, Hai-Liang,Hu, Ping,Wang, Bi-Qin,Cao, Peng
supporting information, p. 13398 - 13405 (2020/09/02)
The iridium-catalyzed enantioselective coupling reaction of vinyl azides and allylic electrophiles is presented and provides access to β-chiral carbonyl derivatives. Vinyl azides are used as acetamide enolate or acetonitrile carbanion surrogates, leading to γ,δ-unsaturated β-substituted amides as well as nitriles with excellent enantiomeric excess. These products are readily transformed into chiral N-containing building blocks and pharmaceuticals. A mechanism is proposed to rationalize the chemoselectivity of this coupling reaction.
Size-Exclusion Borane-Catalyzed Domino 1,3-Allylic/Reductive Ireland–Claisen Rearrangements: Impact of the Electronic and Structural Parameters on the 1,3-Allylic Shift Aptitude
Fegyverneki, Dániel,Kolozsvári, Natália,Molnár, Dániel,Egyed, Orsolya,Holczbauer, Tamás,Soós, Tibor
supporting information, p. 2179 - 2183 (2019/01/04)
The reductive Ireland–Claisen rearrangement through borane-mediated hydrosilylation is reported. The method employs a borane catalyst with a special structural design and affords access to synthetically relevant products with high diastereoselectivity. Depending on electronic and structural parameters, the reaction can be coupled with a 1,3-allylic shift, thus the valence isomer of the Ireland–Claisen product is formed.
A Convenient Palladium-Catalyzed Carbonylative Synthesis of (E)-3-Benzylidenechroman-4-ones
Wang, Wei-Feng,Peng, Jin-Bao,Qi, Xinxin,Ying, Jun,Wu, Xiao-Feng
supporting information, p. 3521 - 3524 (2019/02/14)
A convenient palladium-catalyzed carbonylation reaction for the efficient synthesis of (E)-3-benzylidenechroman-4-ones has been developed. Using TFBen as a solid CO source, a range of substituted (E)-3-benzylidenechroman-4-ones were prepared in moderate to good yields with 2-iodophenols and allyl chlorides as the substrates. Additionally, substituted quinolin-4(1H)-ones can also be obtained with 2-iodoaniline as the starting material.
Domino Synthesis of 3-Alkyliden-2,3-Dihydro-4-Quinolones
Raga, Esther,Escolano, Marcos,Torres, Javier,Rabasa-Alca?iz, Fernando,Sánchez-Roselló, María,del Pozo, Carlos
supporting information, p. 1102 - 1107 (2019/01/30)
The synthesis of 3-alkyliden-2,3-dihydro-4-quinolones has been accomplished in a domino fashion through a three-step sequence that comprised an initial aza-Baylis-Hillman reaction, followed by a 1,3-rearrangement and an intramolecular amination. Starting from readily available aryl vinyl ketones and N-tosyl imines, the reaction with PPh3, CsOAc and CuI in CH3CN gave rise, in good overall yields, to final 3-alkyliden-4-quinolone derivatives, valuable scaffolds in medicinal chemistry. The simultaneous addition of two bases, PPh3 and CsOAc, was found to be crucial for the success of the process. While PPh3 promoted the reversible aza-Baylis-Hillman reaction, CsOAc triggered the subsequent 1,3-rearrangement, which shifted the initial equilibrium and allowed to complete the synthetic sequence upon the addition of CuI. (Figure presented.).
Enantioselective addition of selenosulfonates to α,β-unsaturated ketones
Luo, Shilong,Zhang, Nan,Wang, Zhen,Yan, Hailong
supporting information, p. 2893 - 2901 (2018/05/03)
An organo-catalyzed enantioselective addition of selenosulfonates to α,β-unsaturated ketones was developed for the first time. With a chiral squaramide as an efficient catalyst, the desired α-selenylated ketones were obtained in a good yields with high enantioselectivity up to 89% ee, and good results could be obtained on a gram scale. The products could also be efficiently transformed into useful building blocks with a propenylic stereocenter; the strategy presented in this study may find further applications in organic synthesis.
Rhodium-Catalyzed Asymmetric N?H Functionalization of Quinazolinones with Allenes and Allylic Carbonates: The First Enantioselective Formal Total Synthesis of (?)-Chaetominine
Zhou, Yirong,Breit, Bernhard
supporting information, p. 18156 - 18160 (2017/12/13)
An unprecedented asymmetric N?H functionalization of quinazolinones with allenes and allylic carbonates was successfully achieved by rhodium catalysis with the assistance of chiral bidentate diphosphine ligands. The high efficiency and practicality of this method was demonstrated by a low catalyst loading of 1 mol % as well as excellent chemo-, regio-, and enantioselectivities with broad functional group compatibility. Furthermore, this newly developed strategy was applied as key step in the first enantioselective formal total synthesis of (?)-chaetominine.
Expanding the scope of the Babler–Dauben oxidation: 1,3-oxidative transposition of secondary allylic alcohols
Killoran, Patrick M.,Rossington, Steven B.,Wilkinson, James A.,Hadfield, John A.
supporting information, p. 3954 - 3957 (2016/08/09)
We report the catalytic chromium-mediated oxidation of secondary allylic alcohols to give α,β-unsaturated aldehydes with exclusive (E)-stereoselectivity. This facile procedure employs catalytic PCC (5?mol?%) and periodic acid (H5IO6) as a co-oxidant. This transformation occurs specifically with aromatic substituted allyl alcohols containing both electron withdrawing and electron donating substituents as well as a range of functional groups.
