Direct halogenative dearomatization of 2-naphthols by NXS (X = Cl, Br) in water

Abstract

A direct halogenative dearomatization of substituted 2-naphthols was achieved by NXS (X = Cl, Br) in environmentally friendly water at room temperature.

Redox-Neutral Atom-Economic Pd(0)-Catalyzed Dearomatization of β-Naphthols with Alkynes toward Naphthalenones

“…The dearomatization of naphthols has received great attention because this transformation represented an ideal method for the rapid construction of densely functionalized naphthalenones, which are important components of natural products and therapeutic reagents (Figure ). Well-designed strategies such as alkylation, arylation, alkenylation, amination, and halogenation of naphthols as well as hypervalent iodine or transition-metal-catalyzed oxidation have been elegantly unveiled to target these frameworks. Recently, transition-metal-catalyzed allylic substitution reactions have emerged as an alternative method to realize dearomatization of naphthols with allyl carbonates or alcohols as the allylic reagents (Scheme a) .…”

Applications of Oxone® in Organic Synthesis: An Emerging Green Reagent of Modern Era

“…Recently, dearomatization of the arenols has arose as one of the encouraging tools for the construction of various natural products and/or biologically active compounds. The electrophilic chlorinating reagents such as isocyanuric chloride, N ‐chlorosuccinimide (NCS), NaOCl, SO 2 Cl 2, t BuOCl, SbCl 5 , and hypervalent iodine‐based compounds are well known for chlorinative dearomatization of phenols in the literature [158–161] . Therefore, development of the alternative procedures for the chlorinative dearomatization of arenols using safe, inexpensive and eco‐friendly chlorinating reagents are still of high demand.…”

“…The electrophilic chlorinating reagents such as isocyanuric chloride, Nchlorosuccinimide (NCS), NaOCl, SO 2 Cl 2, t BuOCl, SbCl 5 , and hypervalent iodine-based compounds are well known for chlorinative dearomatization of phenols in the literature. [158][159][160][161] Therefore, development of the alternative procedures for the chlorinative dearomatization of arenols using safe, inexpensive and eco-friendly chlorinating reagents are still of high demand. In this connection, quite recently, the group of Ishihara has developed and described a green methodology for the chlorinative dearomatization of arenols 192 encompassing insitu generated chlorinating species from NaCl/oxone beneath mild conditions (Scheme 60).…”

Gold‐Catalyzed Dearomatization of 2‐Naphthols with Alkynes

“…In the realm of catalytic dearomatization reactions, naphthol derivatives are facing growing attention, resulting in the preparation of densely functionalized and stereochemically defined naphthalen‐2(1 H )‐one, which is a molecular motif featured in numerous naturally occurring and bioactive compounds (Figure ). The catalytic dearomatization of 2‐naphthols found elegant applications with the use of strongly activated electrophiles through the realization of new C−X (X: oxidative approach, for example, hydroxylation, amination,, thiolation, and halogenation) as well as C−C bonds at the C(1) position . In the latter case, the use of strongly activated carbon‐based electrophiles is commonly required to access mild reaction conditions and synthetically useful selectivity.…”