18698-96-9Relevant articles and documents
Gold-catalyzed intermolecular [4+1] spiroannulation: via site-selective aromatic C(sp2)-H functionalization and dearomatization of phenol derivatives
Li, Yongfeng,Liu, Lu,Tang, Zhiqiong,Zhang, Junliang
supporting information, p. 8202 - 8205 (2020/08/17)
Herein, we have developed a novel and simple protocol to realize the C-H bond functionalization/dearomatization of naphthols and phenols with ortho-alkynylaryl-α-diazoesters under gold(i) catalysis. In this protocol, various spirocyclic molecules could be obtained in good yields with excellent chemo- and regio-selectivity and moderate to good diastereoselectivity. This journal is
Ruthenium-catalyzed umpolung carboxylation of hydrazones with CO2
Yan, Si-Shun,Zhu, Lei,Ye, Jian-Heng,Zhang, Zhen,Huang, He,Zeng, Huiying,Li, Chao-Jun,Lan, Yu,Yu, Da-Gang
, p. 4873 - 4878 (2018/06/07)
The first ruthenium-catalyzed umpolung carboxylation of hydrazones with CO2 to generate important aryl acetic acids is reported. Besides aldehyde hydrazones, a variety of ketone hydrazones, which have not been successfully applied in previous umpolung reactions with other reactive electrophiles, also show high reactivity and selectivity under mild conditions. Moreover, this operationally simple protocol features good functional group tolerance, is readily scalable, and offers easy derivation of important structures, including bioactive felbinac and adiphenine. Computational studies reveal that this umpolung reaction proceeds through the generation of a Ru-nitrenoid followed by concerted [4 + 2] cycloaddition with CO2.
Stereospecific Synthesis of Tetrahydronaphtho[2,3-b]furans Enabled by a Nickel-Promoted Tandem Reductive Cyclization
Peng, Yu,Xiao, Jian,Xu, Xiao-Bo,Duan, Shu-Ming,Ren, Li,Shao, Yong-Liang,Wang, Ya-Wen
supporting information, p. 5170 - 5173 (2016/10/14)
A Ni-mediated cascade to a stereoselective synthesis of trans-tetrahydronaphtho[2,3-b]furans is efficiently achieved for the first time. The mild reductive system can be easily generated from inexpensive and air-stable materials and shows a broad positional tolerance of substituents that were previously difficult or impossible to access by other methods. Facile syntheses toward new analogues of therapeutic agents (iso)deoxypodophyllotoxin are also reported. In addition, the inherent substrate control is disclosed for the observed unique stereoselectivities during cyclizations.
Expedient drug synthesis and diversification via ortho-C-H iodination using recyclable PdI2 as the precatalyst
Mei, Tian-Sheng,Wang, Dong-Hui,Yu, Jin-Quan
supporting information; experimental part, p. 3140 - 3143 (2010/09/03)
(Figure Presented) Pd(II)-catalyzed ortho-C-H iodination reactions of phenylacetic acid substrates have been achieved using recyclable PdI2 as the precatalyst. This class of substrates is incompatible with the classic amide formation/ortho-lithiation/iodination sequence. The power of this new technology is demonstrated by facile drug functionalization and drastically shortened syntheses of the drugs diclofenac and lumiracoxib.
Silver nanocluster redox-couple-promoted nonclassical electron transfer: An efficient electrochemical wolff rearrangement of α-diazoketones
Sudrik, Surendra G.,Chaki, Nirmalya K.,Chavan, Vilas B.,Chavan, Sambhaji P.,Chavan, Subhash P.,Sonawane, Harikisan R.,Vijayamohanan
, p. 859 - 864 (2007/10/03)
In this work we report the unique electrocatalytic role of benzoic acid protected silver nanoclusters (Agn, mean core diameter 2.5 nm) in the Wolff rearrangement (Scheme 1) of α-diazoketones. More specifically, the presence of a Agn0/Agn+ redox couple facilitates a nonclassical electron-transfer process, involving chemical reaction(s) interposed between two electron-transfer steps occurring in opposite directions. Consequently, the net electron transfer between the electron mediator (Agn) and α-diazoketone is zero. In-situ UV-visible studies using pyridine as a nucleophilic probe indicate the participation of α-ketocarbene/ketene as important reaction intermediates. Controlled potential coulometry of α-diazoketones using Agn as the anode results in the formation of Wolff rearranged carboxylic acids in excellent yield, without sacrificing the electrocatalyst.
Wolff rearrangement of α-diazoketones using in situ generated silver nanoclusters as electron mediators
Sudrik, Surendra G.,Sharma, Jadab,Chavan, Vilas B.,Chaki, Nirmalya K.,Sonawane, Harikisan R.,Vijayamohanan, Kunjukrishna P.
, p. 1089 - 1092 (2007/10/03)
We report Wolff rearrangement of α-diazoketones by in situ generated silver nanoclusters (Agn, 2-4 nm) from silver(I) oxide (Ag 2O) involving a nonclassical electron-transfer process. Our results show that Agn+/Agn0 redox couple allows the initial removal of an electron from α-diazoketone and its back-donation after chemical reaction(s). Controlled potential coulometry (CPC) of various α-diazoketones results in the realization of Wolff-rearranged carboxylic acids in excellent yields.
Copper(I) mediated intramolecular cyclization of 2-(2-amino-phenylethynyl)benzoic and [2-(2-aminophenylethynyl)phenyl]acetic acid esters: A new synthetic step towards isoindolo[2,1-a]indoles and 5H-indolo[2,1-a]isoquinolines
Reboredo, Francisco J.,Treus, Mónica,Estévez, Juan C.,Castedo, Luis,Estévez, Ramón J.
, p. 1603 - 1606 (2007/10/03)
We describe herein parallel synthetic routes to isoindolo[2,1-a]indoles and 5H-indolo[2,1-a]isoquinolines from 2-(2-aminophenylethynyl)benzoic acid esters and [2-(2-aminophenylethynyl)phenyl]acetic acid esters, respectively.
Regioselective synthesis of isoquino[1,2-b][3]benzazepines (homoprotoberberines) through 11-membered-ring stilbene lactams obtained by radical macrocyclization
Rodriguez, Gema,Castedo, Luis,Dominguez, Domingo,Saa, Carlos,Adam, Waldemar
, p. 4830 - 4833 (2007/10/03)
Silylated 11-membered-ring stilbene lactams 3 (E and Z) were easily prepared by intramolecular addition of an aryl radical to a trimethylsilylacetylene. Oxidation of their hindered stilbene double bonds with dioxiranes gave oxidative cleavage of their electron-rich aromatic rings. However, reduction of the amide to an amine functionality in both lactams (E and Z) triggers a regioselective [7,6]-transannular cyclization to isoquino[1,2-b][3]benzazepines (homoprotoberberines).
Controlled double-bond migration in palladium-catalyzed intramolecular arylation of enamidines
Ripa, Lena,Hallberg, Anders
, p. 7147 - 7155 (2007/10/03)
Palladium-catalyzed intramolecular cyclization of N-(N′-tert-butylformimidoyl)-6-[2-(2-iodophenyl)-ethyl]-1,2,3,4- tetrahydropyridine (1a) and N-(N′-tert-butylformimidoyl)-6-[3-(2-iodophenyl)propyl]-1,2,3,4- tetrahydropyridine (1b) respectively results in formation of spiro compounds 1′-(N-tert-butylformimidoyl)-3′,4′-dihydrospiro[indan-1, 2′(1′H)-pyridine] (4a), 1′-(N-tert-butylformimidoyl)-1′,6′-dihydrospiro[indan-1, 2′(3′H)-pyridine] (5a), and 1′-(N-tert-butylformimidoyl)-5′,6′-dihydrospiro[indan-1, 2′(1′H)-pyridine] (6a) and 1′-(N-tert-butylformimidoyl)-3,3′,4,4′- tetrahydrospiro[naphthalene-1(2H),2′(1′H)-pyridine] (4b), 1′-(N-tert-butylformimidoyl)-1′,3,4,6′- tetrahydrospiro[naphthalene-1(2H),2′(3′H)-pyridine] (5b), and 1′-(N-tert-butylformimidoyl)-3,4,5′,6′- tetrahydrospiro[naphthalene-1(2H),2′(1′H)-pyridine] (6b). The double-bond migration process can be controlled, and any of the three double-bond isomers can be prepared by employing proper ligands. A combination of BINAP and the amidine function was required to obtain the isomers 5a and 5b with the double bond in the homoallylic position relative to the aryl group. An electrospray ionization mass spectrometric study was conducted to support suggested reaction intermediates.