82237-85-2Relevant academic research and scientific papers
Catalytic asymmetric inverse-electron-demand oxa-diels-alder reaction of in situ generated ortho-quinone methides with 3-methyl-2-vinylindoles
Zhao, Jia-Jia,Sun, Si-Bing,He, Sai-Huan,Wu, Qiong,Shi, Feng
, p. 5460 - 5464 (2015)
The first catalytic asymmetric inverse-electron-demand (IED) oxa-Diels-Alder reaction of ortho-quinone methides, generated in situ from ortho-hydroxybenzyl alcohols, has been established. By selecting 3-methyl-2-vinylindoles as a class of competent dienophiles, this approach provides an efficient strategy to construct an enantioenriched chroman framework with three adjacent stereogenic centers in high yields and excellent stereoselectivities (up to 99 % yield, >95:5 d.r.; 99.5:0.5 e.r.). The utilization of ortho-hydroxybenzyl alcohols as precursors of dienes and 3-methyl-2-vinylindoles as dienophiles, as well as the hydrogen-bonding activation mode of the substrates met the challenges of a catalytic asymmetric IED oxa-Diels-Alder reaction.
KOH-mediated stereoselective alkylation of 3-bromooxindoles for the synthesis of 3,3′-disubstituted oxindoles with two contiguous all carbon quaternary centres
Devi, Manju,Jadhav, Amol P.,Singh, Ravi P.
supporting information, p. 8445 - 8448 (2021/05/25)
The stereoselective synthesis of 3,3′-disubstituted oxindoles having all-carbon quaternary stereocenters has been achieved using KOH as a base with an excellent diastereomeric ratio (98?:?2). The practicability of the present methodology has been validated with the synthesis of a series of substrates in good to excellent yields. The aesthetic simplicity, accessibility, and eco-friendly base (KOH) have prompted the broader application of the present methodology in organic synthesis.
Manganese catalyzed C-H functionalization of indoles with alkynes to synthesize bis/trisubstituted indolylalkenes and carbazoles: The acid is the key to control selectivity
Shi, Lijun,Zhong, Xiang,She, Houde,Lei, Ziqiang,Li, Fuwei
supporting information, p. 7136 - 7139 (2015/04/27)
The Mn-catalyzed C-H alkenylation reactions of indole with terminal- and internal-alkynes have been developed. In the presence of a catalytic amount of acid, the procedure efficiently affords bis/trisubstituted indolyl-alkenes in a highly regio- and stereo-selective manner. Without the addition of acid, the reaction undergoes a [2+2+2] cyclization process to give carbazoles with release of hydrogen gas. Notably, the directing pyrimidyl group can be readily removed. Experimental studies reveal that the reaction is initiated by a C-H activation step and the acid is the selectivity controller via a hydrogen transfer process. This journal is
Highly diastereo- and enantioselective construction of a spiro[cyclopenta[b]indole-1,3′-oxindole] scaffold via catalytic asymmetric formal [3+2] cycloadditions
Tan, Wei,Li, Xin,Gong, Yu-Xin,Ge, Meng-Di,Shi, Feng
supporting information, p. 15901 - 15904 (2015/01/08)
An organocatalytic asymmetric formal [3+2] cycloaddition of isatin-derived 3-indolylmethanol with 3-methyl-2-vinylindole has been established, leading to highly stereoselective construction of a spiro[cyclopenta[b]indole-1,3′-oxindole] scaffold with the concomitant creation of three contiguous stereogenic centers (72-99% yield, all >95:5 dr, 90-98% ee), one of which is an all-carbon quaternary stereogenic center.
C-2-SIDE CHAIN MODIFICATION OF 2-METHYL-3-ALKYLINDOLES VIA 3-METHYLTHIOINDOLENINES: A NEW APPROACH TO PYRROLOINDOLES
Vice, Susan F.,Friesen, Richard W.,Dmitrienko, Gary I.
, p. 165 - 168 (2007/10/02)
A strategy for side chain alkylation of 2-methyl-3-alkylindoles, involving deprotonation of 3-methylthioindolenines, derived from 2-methyl-3-alkylindoles by reaction with methane sulfenyl chloride, reaction with carbon electrophiles and reduction, is outl
C-2 SIDE CHAIN ALKYLATION OF 2-METHYL-3-ALKYLINDOLES VIA 3-METHOXYINDOLENINES
Vice, Susan F.,Gross, Edward A.,Friesen, Richard W.,Dmitrienko, Gary I.
, p. 829 - 832 (2007/10/02)
3-Methoxyindolenines derived from 2-methyl-3-alkylindoles by bromination-methanolysis undergo base induced alkylation and aldol condensations at the C-2 methyl group.The modified indolenines can be efficiently converted to C-2-side chain alkylated indoles
