2017
DOI: 10.1021/acs.joc.7b02451
|View full text |Cite
|
Sign up to set email alerts
|

Asymmetric Net Cycloaddition for Access to Diverse Substituted 1,5-Benzothiazepines

Abstract: In this study, the isothiourea-catalyzed enantioselective formal [4+3] cycloaddition of various α,β-unsaturated carboxylic acid derivatives with 2-aminothiophenols was developed. Mechanistic studies suggested that the reaction proceeds via a reversible sulfa-Michael addition to α,β-unsaturated acylammonium intermediates, followed by the enantioselective formation of a seven-membered ring, enabling the facile and divergent synthesis of optically active 2- and 3-substituted 1,5-benzothiazepines. This process was… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
2

Citation Types

0
13
0

Year Published

2019
2019
2024
2024

Publication Types

Select...
6
2

Relationship

0
8

Authors

Journals

citations
Cited by 31 publications
(13 citation statements)
references
References 51 publications
0
13
0
Order By: Relevance
“…The absolute configuration was determined to be R, based on X-ray and chiral HPLC analysis (Scheme 5, entry 2 & 3). [35] Fang et al developed an atom economical, enantioselective synthesis of N-unsubstituted 1,5benzothiazepinoe (29) derivatives from of α,β-unsaturated acyl azoliums. The reaction between α-bromoenal (27) with o-aminobenzenethiols (1) performed under the catalysis of chiral N-heterocyclic carbenes (NHC, 28) as a catalyst and sodium acetate (NaOAc) as a base gave excellent yields (50%-70% yields) of final derivative in high (80%-97%ee) ee.…”
Section: Enantioselective Synthesis Of 15-benzothiazepinesmentioning
confidence: 99%
See 1 more Smart Citation
“…The absolute configuration was determined to be R, based on X-ray and chiral HPLC analysis (Scheme 5, entry 2 & 3). [35] Fang et al developed an atom economical, enantioselective synthesis of N-unsubstituted 1,5benzothiazepinoe (29) derivatives from of α,β-unsaturated acyl azoliums. The reaction between α-bromoenal (27) with o-aminobenzenethiols (1) performed under the catalysis of chiral N-heterocyclic carbenes (NHC, 28) as a catalyst and sodium acetate (NaOAc) as a base gave excellent yields (50%-70% yields) of final derivative in high (80%-97%ee) ee.…”
Section: Enantioselective Synthesis Of 15-benzothiazepinesmentioning
confidence: 99%
“…This intermediate on further treatment with MeI in the presence of TfOH in THF/water system at room temperature followed by heating in the presence of TsOH.H 2 O enabled the enantioselective formation of C-S bond and afforded the final products in good to excellent yields (35). The substrate scope was explored and the reaction was successfully upgraded to gram scale (1 g) without the loss of stereoselectivity (Scheme 7).…”
Section: Enantioselective Synthesis Of 15-benzothiazepinesmentioning
confidence: 99%
“… 2 , 3 Various activated Michael acceptors have been successfully used for TMA, 4 e.g. α,β-unsaturated oxazolidinones, 5 imides, 6 nitro alkenyl isoxazoles, 7 thioamides, 8 acylpyrazoles, 9 carboxylic acid anhydrides, 10 and enone diesters. 11 However, due to their low inherent electrophilicity, catalytic asymmetric TMA to unactivated Michael acceptors such as α,β-unsaturated esters, 12 amides, and carboxylic acids 13 remains a challenge.…”
Section: Introductionmentioning
confidence: 99%
“…Isothiourea is a type of amine organocatalysts that contains an imino nitrogen atom with a lone pair of electrons to exhibit nucleophilicity. Various types of substrates, including carboxylic acids, esters, amides, and anhydrides, have been reported to complex with isothiourea to form ammonium enolate intermediates, which can further react with different electrophiles to realize a large number of reaction types (Scheme ). For example, in 2018, the Birman group reported intermolecular [2+2] cycloaddition between carboxylic acids, which can be the precursors of ammonium enolates, and N ‐sulfonylaldimines to form amino derivatives using the isothiourea catalyst with excellent enantiocontrol (Scheme a) .…”
Section: Introductionmentioning
confidence: 99%