30469-82-0Relevant articles and documents
Chiral electron-rich PNP ligand with a phospholane motif: Structural features and application in asymmetric hydrogenation
Wang, Heng,Zhang, Yao,Yang, Tilong,Guo, Xiaochong,Gong, Quan,Wen, Jialin,Zhang, Xumu
supporting information, p. 8796 - 8801 (2020/11/13)
Despite the remarkable reactivity that was achieved by a series of transition-metal catalysts with a PNP type ligand, the electron-rich chiral PNP ligands have still been rarely reported because of the difficulties in synthesis and the nature of air-sensitivity. Herein, we report a novel chiral PNP ligand (Heng-PNP) with both a rigid backbone and a bulky tert-butyl group on the phospholane motif. We successfully obtained its divalent iron complex. The chiral environment of its Ir(III) complex was also discussed with quadrant analysis. This tridentate ligand was applied in iridium-catalyzed asymmetric hydrogenation of challenging diaryl ketones: up to 98% ee and 500 TON are achieved. Computational study showed that the twist of conjugate aryl group in the substrate (induced by the special chiral pocket of Ir/Heng-PNP complex) leads to the energy difference in the enantiodetermining step.
Coupling of aromatic aldehydes with aryl halides in the presence of nickel catalysts with diazabutadiene ligands
Asachenko,Valaeva,Kudakina,Uborsky,Izmer,Kononovich,Voskoboynikov
, p. 456 - 463 (2017/03/08)
Nickel catalysts with diazabutadiene ligands promote cross-coupling of benzaldehydes with aryl halides in the presence of zinc as reducing agent, which leads to the corresponding benzhydrols and benzophenones. The benzophenone percentage considerably increases when lithium chloride additive is used.
Solvent control of product diversity in palladium-catalyzed addition of arylboronic acid to aryl aldehydes
Das, Tuluma,Chakraborty, Amarnath,Sarkar, Amitabha
, p. 5174 - 5178 (2014/12/10)
In Pd-catalyzed arylboronic acid addition to aryl aldehydes, the expected carbinol or asymmetrical ether can be obtained as the major product by altering aqueous solvent composition. Exploiting this methodology with 2-formylbiphenyls as reaction partner, a fluorene scaffold can be readily constructed in two steps.
Highly efficient synthesis of polysubstituted fluorene via iron-catalyzed intramolecular Friedel-Crafts alkylation of biaryl alcohols
Sarkar, Soumen,Maiti, Sukhendu,Bera, Krishnendu,Jalal, Swapnadeep,Jana, Umasish
, p. 5544 - 5547 (2012/11/07)
An efficient and mild Fe(III)-catalyzed intramolecular Friedel-Crafts alkylation of biaryl methanol derivatives has been developed to achieve the substituted fluorene derivatives. The present reaction provides an excellent alternative to published methods
Palladium-imidazolinium carbene-catalyzed arylation of aldehydes with arylboronic acids in water
Kuriyama, Masami,Ishiyama, Natsuki,Shimazawa, Rumiko,Onomura, Osamu
experimental part, p. 6814 - 6819 (2010/10/02)
The catalytic arylation of aldehydes with arylboronic acids in only water was found to be achieved using the palladium/thioether-imidazolinium chloride system in good to excellent yields. This catalytic process showed high tolerance for a broad range of substrates, giving a variety of carbinol derivatives with 2.0-3.0 mol % of the catalyst.
A general and efficient synthesis of substituted fluorenes and heterocycle-fused indenes containing thiophene or indole rings utilizing a Suzuki-Miyaura coupling and acid-catalyzed Friedel-Crafts reactions as key steps
Li, Guijie,Wang, Erjuan,Chen, Haoyi,Li, Hongfeng,Liu, Yuanhong,Wang, Peng George
, p. 9033 - 9043 (2008/12/22)
A general and efficient synthesis of fluorenes or heterocycle-fused indenes including 3-thia-cyclopenta[a]indenes, 9-thia-indeno[1,2-a]indenes, 5,6-dihydroindeno[2,1-b]indoles has been developed. This methodology is realized by a multistep protocol involv
Selective monolithiation of dibromobiaryls using microflow systems
Nagaki, Aiichiro,Takabayashi, Naofumi,Tomida, Yutaka,Yoshida, Jun-ichi
supporting information; experimental part, p. 3937 - 3940 (2009/06/18)
(Chemical Equation Presented) Selective monolithiation of dibromobiaryls, such as 2,2′-dibromobiphenyl, 4,4′-dibromobiphenyl, 2,7-dibromo-9,9-dioctylfluorene, 2,2′-dibromo-1,1′-binaphthyl, and 5,5′-dibromo-2,2′-bithiophene, with 1 equiv of n-butyllithium followed by the reaction with electrophiles was achieved using a microflow system by virtue of fast micromixing and precise temperature control. Sequential introduction of two different electrophiles based on this method was also achieved using a microflow system composed of four micromixers and four microtube reactors.
A LiCl-mediated Br/Mg exchange reaction for the preparation of functionalized aryl- and heteroarylmagnesium compounds from organic bromides
Krasovskiy, Arkady,Knochel, Paul
, p. 3333 - 3336 (2007/10/03)
A wide range of aryl and heteroaryl bromides, which are usually sluggish in exchange reactions, are readily converted into the corresponding Grignard reagents by means of a Br/Mg exchange reaction triggered by iPrMgCl·LiCl (see scheme). These Grignard intermediates react with electrophiles in good yields.
Synthesis of biaryls by intramolecular radical transfer in phosphinates
Clive,Kang
, p. 6083 - 6091 (2007/10/03)
Phosphinates 20a-35a give biaryls 20b-35b on heating with stannanes in the presence of AIBN. The process involves a radical ipso substitution on the migrating aryl ring.
Amino acid derivatives
-
, (2008/06/13)
Described herein are compounds having the general formula: wherein: Ar1 and Ar2 are independently selected aryl groups, optionally substituted with substituents selected from the group consisting of alkyl, cycloalkyl, alkoxy, alkanoyl, aralkyl, aralkyloxy
