1
|
Hong JE, Yoon J, Baek W, Kim K, Kwak JH, Park Y. Electrochemical C(sp 3)-H Lactonization of 2-Alkylbenzoic Acids toward Phthalides. Org Lett 2023; 25:298-303. [PMID: 36583568 DOI: 10.1021/acs.orglett.2c04211] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Herein, we report direct electrochemical C(sp3)-H lactonization of 2-alkylbenzoic acids toward phthalides. The reaction provides a wide substrate scope of 2-alkylbenzoic acids bearing primary to tertiary C(sp3)-H bonds by utilizing a graphite anode, dichloromethane (DCM) solvent, hexafluoroisopropanol (HFIP) cosolvent, and n-Bu4NClO4 electrolyte. Our synthetic approach offers a simple, intuitive, and atom-economical protocol to synthesize various phthalides (25 examples, up to 92% yield) and obtain other 5- and 6-membered lactones (10 examples, up to 83% yield).
Collapse
Affiliation(s)
- Jee Eun Hong
- College of Pharmacy, Inje Institute of Pharmaceutical Sciences and Research, Inje University, 197 Inje-ro, Gimhae, Gyeongnam 50834, Republic of Korea
| | - Jisong Yoon
- College of Pharmacy, Inje Institute of Pharmaceutical Sciences and Research, Inje University, 197 Inje-ro, Gimhae, Gyeongnam 50834, Republic of Korea
| | - Woohyun Baek
- College of Pharmacy, Inje Institute of Pharmaceutical Sciences and Research, Inje University, 197 Inje-ro, Gimhae, Gyeongnam 50834, Republic of Korea
| | - Kyumin Kim
- College of Pharmacy, Inje Institute of Pharmaceutical Sciences and Research, Inje University, 197 Inje-ro, Gimhae, Gyeongnam 50834, Republic of Korea
| | - Jae-Hwan Kwak
- College of Pharmacy, Chungbuk National University, 194-21 Osongsaengmyeong 1-ro, Heungdeok-gu, Cheongju, Chungbuk 28160, Republic of Korea
| | - Yohan Park
- College of Pharmacy, Inje Institute of Pharmaceutical Sciences and Research, Inje University, 197 Inje-ro, Gimhae, Gyeongnam 50834, Republic of Korea
| |
Collapse
|
2
|
Wang J, Yi WJ. Practical N-Hydroxyphthalimide-Mediated Oxidation of Sulfonamides to N-Sulfonylimines. Molecules 2019; 24:molecules24203771. [PMID: 31635092 PMCID: PMC6832120 DOI: 10.3390/molecules24203771] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/16/2019] [Accepted: 10/18/2019] [Indexed: 02/04/2023] Open
Abstract
A new method to prepare sulfonylimines through the oxidation of sulfonamides mediated by N-hydroxyphthalimide under mild conditions has been developed. Compared to reported oxidation methods, broader substrates scope and milder conditions were achieved in our method. Importantly, this oxidation method can afford N-sulfonyl enaminones using Mannich products as starting materials. Additionally, the one-pot Friedel-Crafts arylation reaction of unseparated N-sulfonylimine formed in our system with 1,3,5-trimethoxybenzene was successful without any additional catalyst.
Collapse
Affiliation(s)
- Jian Wang
- Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu 610052, China.
| | - Wen-Jing Yi
- College of Chemistry and Environmental Protection Engineering, Southwest Minzu University, Chengdu 610041, China.
| |
Collapse
|