Divergent role of PIDA and PIFA in the AlX₃ (X = Cl, Br) halogenation of 2-naphthol: a mechanistic study

• Kevin A. Juárez-Ornelas,
• Manuel Solís-Hernández,
• Pedro Navarro-Santos,
• J. Oscar C. Jiménez-Halla and
• César R. Solorio-Alvarado

Beilstein J. Org. Chem. 2024, 20, 1580–1589, doi:10.3762/bjoc.20.141

• an equilibrium of Cl–I(Ph)–OTFA–AlCl3 and [Cl–I(Ph)][OTFA–AlCl3], rather than PhICl2 being the active species. On the other hand, bromination using PIDA and AlBr3 was more efficient, wherein the intermediate Br–I(Ph)–OAc–AlBr3 was formed as active brominating species. Similarly, PhIBr2 was higher in

• stoichiometry or the formation of PhICl2 as chlorinating species, were also investigated and ruled out. Thus, for the chlorination of 2-naphthol with the PIFA/AlCl3, 1:1 system, we found that in general, once the intermediate I-1–Cl is formed, the following coordination of 2-naphthol with the TFAO ligand via

• less probable route. This result also confirms the relevance of using two equivalents of aluminum chloride. The aromatic chlorination with iodine(III) reagents broadly employs PhICl2 [7]. Thus, we explored two alternatives for the chlorination of 2-naphthol to identify or rule out this potential

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl₂ and NH₄SCN/KSeCN

• Jialiang Wu,
• Haofeng Shi,
• Xuemin Li,
• Jiaxin He,
• Chen Zhang,
• Fengxia Sun and
• Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

• Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China 10.3762/bjoc.20.128 Abstract A series of 4-thio/seleno-cyanated pyrazoles was conveniently synthesized from 4-unsubstituted pyrazoles using NH4SCN/KSeCN as thio/selenocyanogen sources and PhICl2 as the hypervalent iodine

• oxidant. This metal-free approach was postulated to involve the in situ generation of reactive thio/selenocyanogen chloride (Cl–SCN/SeCN) from the reaction of PhICl2 and NH4SCN/KSeCN, followed by an electrophilic thio/selenocyanation of the pyrazole skeleton. Keywords: PhICl2; pyrazoles; selenocyanation

• efficient method for a smooth selenocyanation of pyrazole compounds. Results and Discussion In our previous work we reported that a regioselective C-5 thiocyanation of the 2-pyridone skeleton could be realized via a PhICl2-mediated electrophilic thiocyanation approach [54]. Inspired by this previous work

Metal-free mechanochemical oxidations in Ertalyte^® jars

• Andrea Porcheddu,
• Francesco Delogu,
• Lidia De Luca,
• Claudia Fattuoni and
• Evelina Colacino

Beilstein J. Org. Chem. 2019, 15, 1786–1794, doi:10.3762/bjoc.15.172

• compounds under very mild conditions [6][7]. Initially used in a stoichiometric amount [8], over the last 20 years it has been exploited successfully in catalytic quantities in combination with other oxidants [9]. A diverse range of co-oxidant agents (N-chlorosuccinimide, NaOCl, Oxone®, PhIO, PhICl2, PhI

Rapid transformation of sulfinate salts into sulfonates promoted by a hypervalent iodine(III) reagent

• Elsa Deruer,
• Vincent Hamel,
• Samuel Blais and
• Sylvain Canesi

Beilstein J. Org. Chem. 2018, 14, 1203–1207, doi:10.3762/bjoc.14.101

• reagents. A number of iodanes with various oxidation states have been developed since the pioneering work of the German chemist Willgerodt, who synthesized PhICl2 [5]. Iodane reagents have been extensively used in applications such as oxidation, rearrangement, cross-coupling, functionalization

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• ) dichlorides for free radical chlorinations [25]. In this regard, phenyl iodine(III) dichloride (PhICl2) is an effective free radical chlorinating agent for hydrocarbons [26][27]. Importantly, the mechanism does not involve the liberation of Cl2, followed by the textbook sequence of steps. Rather, hydrogen

• helical chiralities (see Figure S2, Supporting Information File 1), affording a meso stereoisomer. Finally, attempts have been made to extend the preceding chemistry in several directions. In screening experiments, all of the fluorous iodine(III) dichlorides assayed, as well as PhICl2, were competent for

Pyridylidene ligand facilitates gold-catalyzed oxidative C–H arylation of heterocycles

• Kazuhiro Hata,
• Hideto Ito,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2015, 11, 2737–2746, doi:10.3762/bjoc.11.295

• PhICl2 (see Experimental section and Supporting Information File 1 for details) [114]. The X-ray crystallographic analysis was successfully accomplished with a colorless single crystal of AuCl3(PyC), which was recrystallized from nitrobenzene and pentane (Figure 3) [115]. The X-ray crystal structure

• by flash chromatography on silica gel to afford the coupling product 3 (Table 2). Oxidation of AuCl(PyC): The oxidation of AuCl(PyC) was performed according to the literature [16]. PhICl2 (54.8 mg, 0.20 mmol) was added into a solution of AuCl(PyC) (128 mg, 0.20 mmol) in CH2Cl2 (2.0 mL) under N2

Organic synthesis using (diacetoxyiodo)benzene (DIB): Unexpected and novel oxidation of 3-oxo-butanamides to 2,2-dihalo-N-phenylacetamides

• Wei-Bing Liu,
• Cui Chen,
• Qing Zhang and
• Zhi-Bo Zhu

Beilstein J. Org. Chem. 2012, 8, 344–348, doi:10.3762/bjoc.8.38

• , exemplified by the formation of 2a, is depicted in Scheme 6. Initially, the reaction involved generation of the known chlorinating agent (dichloroiodo)benzene (PhICl2) [39], followed by dichlorination of the β-keto amide of 3-oxo-N-phenylbutanamide (1a) to give intermediate 4. It is well known that Lewis