View in EDS

Acid-catalyzed highly diastereoselective and effective synthesis of 1,3-disubstituted tetrahydropyrano[3,4-b]indoles.

Saved in:
Bibliographic Details
Title: Acid-catalyzed highly diastereoselective and effective synthesis of 1,3-disubstituted tetrahydropyrano[3,4-b]indoles.
Authors: Wang, Pei1,2, Zhao, Jia-Zhen1,2, Li, Hong-Feng1,2, Liang, Xiang-Ming1,2, Zhang, Ya-Lun1,2, Da, Chao-Shan1,2 dachaoshan@lzu.edu.cn
Source: Tetrahedron Letters: International Organ for the Rapid Publication of Preliminary Communications in Organic Chemistry. Jan2017, Vol. 58 Issue 2, p129-133. 5p.
Subjects: Stereoselective reactions, Indole compounds, Substituents (Chemistry), Trifluoroacetic acid, Tryptophol, Cost effectiveness
Abstract: We successfully explored for the first time that trifluoroacetic acid (TFA) can effectively catalyze the oxa-Pictet-Spengler reaction of secondary tryptophols and acetals to synthesize 1,3-disubstituted 1,3,4,9-tetrahydropyrano[3,4- b ]indoles in high yield (up to >99%) and diastereoselectivity (>20:1). The secondary tryptophols were synthesized from indole-3-acetic acid. The one-pot synthesis of tetrahydropyrano[3,4- b ]indoles was successfully developed from secondary tryptophols and in situ prepared acetals from aldehydes and trimethylorthoformate and thus the cost-efficiency of the protocol was effectively enhanced. Finally, the catalytic asymmetric synthesis of the 1,3-disubstituted tetrahydropyrano[3,4- b ]indole was also demonstrated after enantioselective achievement of highly enantiopure secondary tryptophols. [ABSTRACT FROM AUTHOR]
Copyright of Tetrahedron Letters: International Organ for the Rapid Publication of Preliminary Communications in Organic Chemistry is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:We successfully explored for the first time that trifluoroacetic acid (TFA) can effectively catalyze the oxa-Pictet-Spengler reaction of secondary tryptophols and acetals to synthesize 1,3-disubstituted 1,3,4,9-tetrahydropyrano[3,4- b ]indoles in high yield (up to >99%) and diastereoselectivity (>20:1). The secondary tryptophols were synthesized from indole-3-acetic acid. The one-pot synthesis of tetrahydropyrano[3,4- b ]indoles was successfully developed from secondary tryptophols and in situ prepared acetals from aldehydes and trimethylorthoformate and thus the cost-efficiency of the protocol was effectively enhanced. Finally, the catalytic asymmetric synthesis of the 1,3-disubstituted tetrahydropyrano[3,4- b ]indole was also demonstrated after enantioselective achievement of highly enantiopure secondary tryptophols. [ABSTRACT FROM AUTHOR]
ISSN:00404039
DOI:10.1016/j.tetlet.2016.11.110