- Total Synthesis of Ritterazine B
-
The first total synthesis of the cytotoxic alkaloid ritterazine B is reported. The synthesis features a unified approach to both steroid subunits, employing a titanium-mediated propargylation reaction to achieve divergence from a common precursor. Other key steps include gold-catalyzed cycloisomerizations that install both spiroketals and late stage C-H oxidation to incorporate the C7′ alcohol.
- Nakayama, Yasuaki,Maser, Michael R.,Okita, Tatsuya,Dubrovskiy, Anton V.,Campbell, Taryn L.,Reisman, Sarah E.
-
supporting information
p. 4187 - 4192
(2021/04/06)
-
- Method for compounding benzofuran derivatives by adding C-O bonds into olefin molecules through non-metallic Lewis acid catalysis
-
The invention provides a method for compounding benzofuran derivatives by adding C-O bonds into olefin molecules through non-metallic Lewis acid catalysis. The method includes step 1, subjecting raw materials, namely phenol derivatives, to three-step reactions to obtain olefin serving as a reaction substrate; step 2, adding non-metallic Lewis acid and methylbenzene into the reaction substrate obtained in the step 1, and obtaining the benzofuran derivatives after reaction. The method has the advantages that the non-metallic Lewis acid is taken as a catalyst during reaction, so that pollution ofresidual metal catalysts to products is avoided, and troubles in post-treatment are omitted.
- -
-
Paragraph 0039; 0041; 0043; 0044
(2018/10/02)
-
- Palladium-Catalyzed Tandem Oxidative Arylation/Olefination of Aromatic Tethered Alkenes/Alkynes
-
We describe herein a palladium-catalyzed tandem oxidative arylation/olefination reaction of aromatic tethered alkenes/alkynes for the synthesis of dihydrobenzofurans and 2 H-chromene derivatives. This reaction features a 1,2-difunctionalization of C?C π-bond with two C?H bonds using O2as terminal oxidant at room temperature. The products obtained are valuable synthons and important scaffolds in biological agents and natural products.
- Gao, Yang,Gao, Yinglan,Wu, Wanqing,Jiang, Huanfeng,Yang, Xiaobo,Liu, Wenbo,Li, Chao-Jun
-
supporting information
p. 793 - 797
(2017/02/05)
-
- Development and Mechanistic Study of Quinoline-Directed Acyl C-O Bond Activation and Alkene Oxyacylation Reactions
-
The intramolecular addition of both an alkoxy and acyl substituent across an alkene, oxyacylation of alkenes, using rhodium catalyzed C-O bond activation of an 8-quinolinyl ester is described. Our unsuccessful attempts at intramolecular carboacylation of ketones via C-C bond activation ultimately informed our choice to pursue and develop the intramolecular oxyacylation of alkenes via quinoline-directed C-O bond activation. We provide a full account of our catalyst discovery, substrate scope, and mechanistic experiments for quinoline-directed alkene oxyacylation.
- Hoang, Giang T.,Walsh, Dylan J.,McGarry, Kathryn A.,Anderson, Constance B.,Douglas, Christopher J.
-
p. 2972 - 2983
(2017/03/23)
-
- Pd-Catalyzed regioselective hydroesterification of 2-allylphenols to seven-membered lactones without external CO gas
-
Effective Pd-catalyzed regioselective hydroesterification of 2-allylphenols with phenyl formate is described. A variety of seven-membered lactones can be obtained in good yields under mild conditions without the use of toxic CO gas.
- Chang, Wenju,Li, Jingfu,Ren, Wenlong,Shi, Yian
-
supporting information
p. 3047 - 3052
(2016/03/19)
-
- One-pot method for regioselective bromination and sequential carbon-carbon bond-forming reactions of allylic alcohol derivatives
-
An efficient one-pot method for the regioselective bromination of allylic alcohol derivatives (two-step reaction sequence) followed by Sonogashira, Negishi, or Suzuki-Miyaura coupling reactions in the same reaction vessel (three-step reaction sequence) ha
- Kutsumura, Noriki,Matsubara, Yusuke,Niwa, Kentaro,Ito, Ai,Saito, Takao
-
p. 3337 - 3346
(2013/06/27)
-
- Insertion of an Alkene into an ester: Intramolecular oxyacylation reaction of alkenes through acyl C-O bond activation
-
Atom economy and esters: compatible now! The first catalytic insertion of a C-C bond into an acyl C-O bond was achieved using rhodium catalysts (see scheme). The products are β-alkoxy ketones with a fully substituted carbon center. Quinoline chelating groups were employed to stabilize the Rh-alkoxide intermediate.
- Hoang, Giang T.,Reddy, Venkata Jaganmohan,Nguyen, Huy H. K.,Douglas, Christopher J.
-
supporting information; experimental part
p. 1882 - 1884
(2011/04/16)
-
- Pd-Catalyzed intramolecular oxyalkynylation of alkenes with hypervalent iodine
-
(Figure presented) The first example of intramolecular oxyalkynylation of nonactivated alkenes using oxidative Pd chemistry is reported. Both phenol and aromatic or aliphatic acid derivatives could be used under operator-friendly conditions (room temperature, technical solvents, under air). The discovery of the superiority of benzlodoxolone-derlved hypervalent iodine reagent 3d as an alkyne transfer reagent further expands the rapidly increasing utility of hypervalent iodine reagents in catalysis and is expected to have important implications for other similar processes.
- Nicolal, Stefano,Erard, Stephane,Gonzalez, Davinla Fernandez,Waser, Jerome
-
supporting information; experimental part
p. 384 - 387
(2010/03/04)
-
- Regioselective iron-catalyzed decarboxylative allylic etherification
-
[Chemical Equation Presented] An anionic iron complex catalyzes the decarboxylative allylation of phenols to form allylic ethers in high yield. The allylation is regioselective rather than regiospecific. This suggests that the allylation proceeds through π-allyl iron intermediates in contrast to related allylations of carbon nucleophiles that have been proposed to proceed via π-allyl complexes. Ultimately, iron catalysts have the potential to replace more expensive palladium catalysts that are typically utilized for decarboxylative couplings.
- Trivedi, Rushi,Tunge, Jon A.
-
supporting information; experimental part
p. 5650 - 5652
(2010/02/28)
-
- Copper-catalyzed formation of carbon-heteroatom and carbon-carbon bonds
-
The present invention relates to copper-catalyzed carbon-heteroatom and carbon-carbon bond-forming methods. In certain embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-nitrogen bond between the nitrogen atom of an amide or amine moiety and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In additional embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-nitrogen bond between a nitrogen atom of an acyl hydrazine and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In other embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-nitrogen bond between the nitrogen atom of a nitrogen-containing heteroaromatic, e.g., indole, pyrazole, and indazole, and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. In certain embodiments, the present invention relates to copper-catalyzed methods of forming a carbon-oxygen bond between the oxygen atom of an alcohol and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. The present invention also relates to copper-catalyzed methods of forming a carbon-carbon bond between a reactant comprising a nucleophilic carbon atom, e.g., an enolate or malonate anion, and the activated carbon of an aryl, heteroaryl, or vinyl halide or sulfonate. Importantly, all the methods of the present invention are relatively inexpensive to practice due to the low cost of the copper comprised by the catalysts.
- -
-
-
- Copper-catalyzed coupling of aryl iodides with aliphatic alcohols.
-
[reaction: see text] A simple and mild method for the coupling of aryl iodides and aliphatic alcohols that does not require the use of alkoxide bases is described. The reactions can be performed in neat alcohol. For more precious alcohols, the etherificat
- Wolter, Martina,Nordmann, Gero,Job, Gabriel E,Buchwald, Stephen L
-
p. 973 - 976
(2007/10/03)
-
- Preparation of chiral building blocks for a highly convergent vitamin E synthesis. Systematic investigations on the enantioselectivity of the sharpless bishydroxylation
-
The enantioselective bishydroxylation of protected 2-methylprop-2-enol 15 and 3-methylbut-3-en-1-ol 16 to give the corresponding diols 18 and 19, respectively, which can be transformed into building blocks for the synthesis of natural vitamin E, is described. It is shown that the enantioselectivity of the bishydroxylation reaction clearly depends on the type of protecting group and its distance from the alkene moiety, with 96% ee for 16a and 16f as the best and 8% ee for 15d as the lowest result.
- Tietze, Lutz F.,Goerlitzer, Jochen
-
p. 873 - 878
(2007/10/03)
-
- Convenient Synthesis of 1-Butyl-2,3,5-trioxygenated Benzenes: Synthesis of the Di-O-methyl Ether of the Aglycone of Cesternoside A
-
The synthesis of the di-O-methyl ether of the aglycone of cesternoside A (3 = 10a), 2-iso-butyl-4,6-dimethoxyphenol (10b) and 2-sec- and 2-iso-butyl-4-methoxyphenols (10c and 10d) is described from the corresponding phenols (7a and 7b) via the intermediac
- Mali, Raghao S.,Garkhedkar, Milind P.,Sindkhedkar, Milind D.,Dhavale, Dilip D.
-
p. 342 - 343
(2007/10/03)
-