A Concise, Catalyst-Free Synthesis of Davis’ Oxaziridines using Sodium Hypochlorite

Abstract

N-Sulfonyloxaziridines (Davis’ oxaziridines) can be synthesized by reacting the corresponding N-sulfonylimines with aqueous sodium hypochlorite in acetonitrile without any catalyst. The pH of the aqueous sodium hypochlorite is crucial to obtain the product in high yield. Optimized conditions are presented that allow synthetically useful Davis’ oxaziridines to be easily obtained in up to 90% yields from the corresponding imines by using inexpensive, stable, environmentally friendly sodium hypochlorite pentahydrate crystals as the oxidant, with high reproducibility.

Recent Advances in the Preparations and Synthetic Applications of Oxaziridines and Diaziridines

“…The synthesized compounds (25) were employed to oxidize sulfides. [26,27] It was revealed that due to the presence of trichloromethyl (23) and nitro groups (25) on the dihydroisoquinoline skeleton, the oxaziridine became more electrophilic and the reaction of oxygen transfer into sulphide occured in absence of acid (see section 3.1.2).…”

“…developed a catalyst‐free, environment‐friendly method towards the Davis oxaziridines 20 via the reaction of N ‐sulfonyl imines 19 with sodium hypochlorite (NaOCl) in aqueous acetonitrile under basic conditions (Scheme 7). [23] …”

“…[22] In a recent report, Kirihara et al developed a catalyst-free, environment-friendly method towards the Davis oxaziridines 20 via the reaction of N-sulfonyl imines 19 with sodium hypochlorite (NaOCl) in aqueous acetonitrile under basic conditions (Scheme 7). [23] The heterocyclic ring systems continue to attract considerable attention due to their wide range of biological activities. In this regard, dihydroisoquinolines exhibited various biological properties, including anti-tumor, anti-inflammatory and antihypertensive activities.…”

Sodium Hypochlorite Pentahydrate as a Reagent for the Cleavage of trans-Cyclic Glycols

“…However, aq NaOCl was useless for the oxidative cleavage of cis- and trans- 1a (Table , runs 1–4). The reaction of these compounds with NaOCl·5H 2 O was next approached because we recently have reported that NaOCl·5H 2 O is a superior reagent to conventional aq NaOCl in the oxidation of organic compounds . For comparison, we also examined the reaction with conventional reagents including sodium periodate (NaIO 4 ), Pb­(OAc) 4 and PhI­(OAc) 2 .…”

“…Although conventional aq NaOCl has been used as an oxidant for glycol cleavage, it is not effective in cleaving highly hindered bicyclic glycol 1a , as shown in Table (runs 1–4). This is because aq NaOCl is not effective enough to have a high pH value (>13) compared to the low pH (10–11) of NaOCl·5H 2 O crystals in several oxidation reactions . Therefore, the effect of pH on the glycol cleavage reaction was examined using 1e as a substrate (Table ).…”