Green Aerobic Oxidation of Thiols to Disulfides by Flavin–Iodine Coupled Organocatalysis

Oka, Marina; Kozako, Ryo; Iida, Hiroki

doi:10.1055/a-1520-9916

Cited by 11 publications

(5 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The oxidation of thiols to disulfides using iodine has demonstrated a wide range of reactive groups tolerated [31]. Additionally, iodine has previously been employed as a catalyst in thiol oxidation combined with additives like DMSO, H2O2, and flavin [32][33][34]. This study showcases its effectiveness as a catalyst in catalyzing aerobic thiol oxidation at elevated temperatures using only 5 mol% of iodine, which is more cost-effective and environmentally friendly compared to previous studies.…”

Section: Introductionmentioning

confidence: 81%

Application of Iodine as a Catalyst in Aerobic Oxidations: A Sustainable Approach for Thiol Oxidations

Wang,

Chen,

Qin

et al. 2023

Molecules

View full text Add to dashboard Cite

Iodine is a well-known oxidant that is widely used in organic syntheses. Thiol oxidation by stoichiometric iodine is one of the most commonly employed strategies for the synthesis of valuable disulfides. While recent advancements in catalytic aerobic oxidation conditions have eliminated the need for stoichiometric oxidants, concerns persist regarding the use of toxic or expensive catalysts. In this study, we discovered that iodine can be used as a cheap, low-toxicity catalyst in the aerobic oxidation of thiols. In the catalytic cycle, iodine can be regenerated via HI oxidation by O2 at 70 °C in EtOAc. This protocol harnesses sustainable oxygen as the terminal oxidant, enabling the conversion of primary and secondary thiols with remarkable efficiency. Notably, all 26 tested thiols, encompassing various sensitive functional groups, were successfully converted into their corresponding disulfides with yields ranging from >66% to 98% at a catalyst loading of 5 mol%.

show abstract

Section: Introductionmentioning

confidence: 81%

Application of Iodine as a Catalyst in Aerobic Oxidations: A Sustainable Approach for Thiol Oxidations

Wang,

Chen,

Qin

et al. 2023

Molecules

View full text Add to dashboard Cite

show abstract

“…As the ideal oxidants, molecular oxygen or hydrogen peroxide is not only highly atomically economical, cheap and easily available, but also can minimize the production of harmful byproducts (Eq. 1) [22][23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Organic superbase-catalyzed oxidation of alkanethiols to dialkyl disulfides by elemental sulfur

Zhang

Wang

et al. 2023

Res Chem Intermed

View full text Add to dashboard Cite

Under atmospheric pressure and solvent-free conditions, organic superbase (SB) catalyzed the oxidation of alkanethiols (RSH) to dialkyl disul de (R 2 S 2 ) by using sulfur as oxidant was investigated. The results showed that amidines (DBU, DBN) and guanidines (BTMG, MTBD, TMG) exhibited signi cantly higher catalytic activity than common organic bases. Under the condition of 3.0 molar ratio of RSH/S (50 mol% excess of RSH), 99~100% yield of (n-C 8 H 17 ) 2 S 2 could be obtained with 0.1 mol% SB and more than 95% yield of (n-C 8 H 17 ) 2 S 2 could be also obtained even if with 0.001 mol% SB. The yield of target product R 2 S 2 (R = alkyl, phenyl) was still obtained above 90% when the molar ratio of RSH/S was 2.1 (5 mol% excess of RSH). R 2 S 3 was the only by-product, and no R 2 S 4 was generated. The deprotonation ability of SB to RSH is signi cantly higher than that of common organic bases, and RS − is the key active species in the catalytic reaction. This synthetic method has the advantages of operational simplicity, inexpensive, and the applicability to 20-30 g scale synthesis strengthen its potential applications for preparing disul de at an industrial scale.

show abstract

“…6f As a result of the high demand for a simple and sustainable synthetic route for S–S bond formation, traditional metal-catalyzed, aerial-oxidative, and thermal protocols are being developed ( Scheme 1 ). 7 Recently, Lie et al developed an electro-oxidative technique for direct S–S bond construction. 7c The first successful report on photoinduced thiol coupling was done by Wu and co-workers in 2014, 8a where CdSe quantum dot-based photocatalysts have been used.…”

Section: Introductionmentioning

confidence: 99%

Tuning Selectivity in the Visible-Light-Promoted Coupling of Thiols with Alkenes by EDA vs TOCO Complex Formation

Das

Thomas

2023

ACS Omega

View full text Add to dashboard Cite

The visible-light-promoted catalyst-free condition has been demonstrated for self-and cross-coupling reactions of thiols in an ambient atmosphere. Further, synthesis of β-hydroxysulfides is accomplished under very mild conditions involving the formation of an electron donor−acceptor (EDA) complex between a disulfide and an alkene. However, the direct reaction of thiol with alkene via the formation of a thiol−oxygen co-oxidation (TOCO) complex failed to produce the desired compounds in high yields. The protocol was successful with several aryl and alkyl thiols for the formation of disulfides. However, the formation of β-hydroxysulfides required an aromatic unit on the disulfide fragment, which supports the formation of the EDA complex during the course of the reaction. The approaches presented in this paper for the coupling reaction of thiols and the synthesis of βhydroxysulfides are unique and do not require toxic organic or metal catalysts.

show abstract

Green Aerobic Oxidation of Thiols to Disulfides by Flavin–Iodine Coupled Organocatalysis

Cited by 11 publications

References 13 publications

Application of Iodine as a Catalyst in Aerobic Oxidations: A Sustainable Approach for Thiol Oxidations

Application of Iodine as a Catalyst in Aerobic Oxidations: A Sustainable Approach for Thiol Oxidations

Organic superbase-catalyzed oxidation of alkanethiols to dialkyl disulfides by elemental sulfur

Tuning Selectivity in the Visible-Light-Promoted Coupling of Thiols with Alkenes by EDA vs TOCO Complex Formation

Contact Info

Product

Resources

About