57486-69-8Relevant articles and documents
Intramolecular Anti-Carbolithiation of Alkynes: Stereo-Directing Effect of Lithium-Coordinating Substituents
Ly, Kim Uyen,Boussonnière, Anne,Castanet, Anne-Sophie
supporting information, (2022/01/19)
This paper presents the results of our investigations on the stereochemical course of intramolecular carbolithiation of alkynes. It is shown that the presence of a lithium-chelating propargylic substituent completely reverses the otherwise favored syn-pro
Palladium-Catalyzed [4 + 3] or [2 + 2 + 3] Annulation via C-H Activation and Subsequent Decarboxylation: Access to Heptagon-Embedded Polycyclic Aromatic Hydrocarbons
Yang, Xiumei,Chen, Xiahong,Xu, Yankun,Zhang, Minghao,Deng, Guobo,Yang, Yuan,Liang, Yun
supporting information, p. 2610 - 2615 (2021/04/12)
The construction of a seven-membered ring in the polycyclic aromatic hydrocarbon skeleton remains a notoriously difficult but attractive challenge. Herein a novel palladium-catalyzed [4 + 3] decarboxylative annulation of 2-iodobiphenyls with 2-(2-halophenyl)acrylic acids is reported, which provides an efficient approach for assembling various tribenzo[7]annulenes via a C-H activation and decarboxylation process. Moreover, tribenzo[7]annulenes can be also synthesized via a [2 + 2 + 3] decarboxylative annulation strategy by employing readily available 1,2-halobenzenes, phenylboronic acids, and 2-(2-halophenyl)acrylic acids.
Borylation of Unactivated C(sp3)-H Bonds with Bromide as a Traceless Directing Group
Zhang, Ge,Li, Meng-Yao,Ye, Wen-Bo,He, Zhi-Tao,Feng, Chen-Guo,Lin, Guo-Qiang
supporting information, p. 2948 - 2953 (2021/05/05)
A palladium-catalyzed alkyl C-H borylation with bromide as a traceless directing group is described, providing a convenient approach to access alkyl boronates bearing a β-all-carbon quaternary stereocenter. The protocol features a broad substrate scope, excellent site selectivity, and good functional group tolerance.
B(C6F5)3-catalyzed O-H insertion reactions of diazoalkanes with phosphinic acids
Jiang, Jun,Zhang, Xinzhi,Zhang, Yangyang,Zhao, Jincheng
supporting information, p. 5772 - 5776 (2021/07/12)
A highly efficient base-, metal-, and oxidant-free catalytic O-H insertion reaction of diazoalkanes and phosphinic acids in the presence of B(C6F5)3has been developed. This powerful methodology provides a green approach towards the synthesis of a broad spectrum of α-phosphoryloxy carbonyl compounds with good to excellent yields (up to 99% yield). The protocol features the advantages of operational simplicity, high atom economy, practicality, easy scalability and environmental friendliness.
B(C6F5)3-Catalyzed site-selective N1-alkylation of benzotriazoles with diazoalkanes
Guo, Jing,Mandal, Dipendu,Stephan, Douglas W.,Wu, Yile,Zhao, Yunbo
supporting information, p. 7758 - 7761 (2021/08/13)
Alkylation of benzotriazoles is synthetically challenging, often leading to mixtures of N1 and N2 alkylation. Herein, metal-free catalytic site-selective N1-alkylation of benzotriazoles with diazoalkanes is described in the presence of 10 mol% of B(C6F5)3. These reactions provide N1-alkylated benzotriazoles in good to excellent yields and this protocol is successfully adapted to gram-scale syntheses as well as a derivative with antimicrobial activity.
Internal Nucleophilic Catalyst Mediated Cyclisation/Ring Expansion Cascades for the Synthesis of Medium-Sized Lactones and Lactams
Lawer, Aggie,Rossi-Ashton, James A.,Stephens, Thomas C.,Challis, Bradley J.,Epton, Ryan G.,Lynam, Jason M.,Unsworth, William P.
supporting information, p. 13942 - 13947 (2019/08/28)
A strategy for the synthesis of medium-sized lactones and lactams from linear precursors is described in which an amine acts as an internal nucleophilic catalyst to facilitate a novel cyclisation/ring expansion cascade sequence. This method obviates the n
Sulfoxide ligand metal catalyzed oxidation of olefins
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Page/Page column 106, (2019/05/09)
The enantioselective synthesis of isochroman motifs has been accomplished via Pd(II)-catalyzed allylic C—H oxidation from terminal olefin precursors. Critical to the success of this goal was the development and utilization of a novel chiral aryl sulfoxide-oxazoline (ArSOX) ligand. The allylic C—H oxidation reaction proceeds with the broadest scope and highest levels asymmetric induction reported to date (avg. 92% ee, 13 examples ≥90% ee). Additionally, C(sp3)-N fragment coupling reaction between abundant terminal olefins and N-triflyl protected aliphatic and aromatic amines via Pd(II)/sulfoxide (SOX) catalyzed intermolecular allylic C—H amination is disclosed. A range of 52 allylic amines are furnished in good yields (avg. 76%) and excellent regio- and stereoselectivity (avg. >20:1 linear:branched, >20:1 E:Z). For the first time, a variety of singly activated aromatic and aliphatic nitrogen nucleophiles, including ones with stereochemical elements, can be used in fragment coupling stiochiometries for intermolecular C—H amination reactions.
Metal-Free Tandem Rearrangement/Lactonization: Access to 3,3-Disubstituted Benzofuran-2-(3H)-ones
Santi, Micol,Ould, Darren M. C.,Wenz, Jan,Soltani, Yashar,Melen, Rebecca L.,Wirth, Thomas
supporting information, p. 7861 - 7865 (2019/04/25)
A novel metal-free synthesis of 3,3-disubstituted benzofuran-2-(3H)-ones through reacting α-aryl-α-diazoacetates with triarylboranes is presented. Initially, triarylboranes were successfully investigated in α-arylations of α-diazoacetates, however in the presence of a heteroatom in the ortho position, the boron enolate intermediate undergoes an intramolecular rearrangement to form a quaternary center. The intermediate cyclizes to afford valuable 3,3-disubstituted benzofuranones in good yields.
Rh-Catalyzed Chemoselective [4 + 1] Cycloaddition Reaction toward Diverse 4-Methyleneprolines
Cai, Wangshui,Wu, Junxian,Zhang, Haowei,Jalani, Hitesh B.,Li, Guigen,Lu, Hongjian
, p. 10877 - 10891 (2019/09/12)
An efficient synthesis of 4-methyleneproline derivatives has been developed through an Rh-catalyzed [4 + 1] cycloaddition strategy using 3-methyleneazetidines and diazo compounds. The reaction proceeds under very mild conditions with a high degree of chemoselectivity, and competing experiments revealed that it is the preferred reaction, dominant over the C-H insertion, O-H insertion, and olefin cyclopropanation reactions which are commonly observed in Rh carbene chemistry. This method can incorporate the proline ester scaffold in pharmaceuticals and natural products. The intramolecular version of the reaction effectively provides proline-fused small to medium-sized tricyclic heterocycles. Gram-scale reactions, one-time addition of diazo compounds, and a minimum catalyst loading of 0.1 mol %, proceeded smoothly, implying their practicality.
Macrolide Synthesis through Intramolecular Oxidative Cross-Coupling of Alkenes
Jiang, Bing,Zhao, Meng,Li, Shu-Sen,Xu, Yun-He,Loh, Teck-Peng
supporting information, p. 555 - 559 (2018/02/21)
A RhIII-catalyzed intramolecular oxidative cross-coupling between double bonds for the synthesis of macrolides is described. Under the optimized reaction conditions, macrocycles containing a diene moiety can be formed in reasonable yields and with excellent chemo- and stereoselectivity. This method provides an efficient approach to synthesize macrocyclic compounds containing a 1,3-conjugated diene structure.
