Transition-metal-catalyst-free electroreductive alkene hydroarylation with aryl halides under visible-light irradiation

• Kosuke Yamamoto,
• Kazuhisa Arita,
• Masami Kuriyama and
• Osamu Onomura

Beilstein J. Org. Chem. 2024, 20, 1327–1333, doi:10.3762/bjoc.20.116

• found to be suitable coupling partners. Aryl chloride 1a reacted with tert-butyl acrylate (2b) without any difficulty, providing 3ab in a high yield. Methacrylamide (2c) and acrylonitrile (2d) were transformed into the corresponding products in high yields, but with slightly lower Faradaic efficiency

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

• , might indicate a preassembly between 4-DPAIPN•− and the aryl chloride. Simultaneously, Zhou, Wu and co-workers demonstrated 2,4,5-tri(9H-carbazol-9-yl)-6-(ethyl(phenyl)amino)isophthalonitrile (3CzEPAIPN) as yet another isophthalonitrile derived photocatalyst suitable for conPET chemistry [57]. Similar

• late-stage functionalization (17i and 17j) (Figure 12A). Interestingly, sodium oxalate could be used as the electron donor provided a catalytic loading of 4-cyanopyridine was added. Although the role of the latter species was not proposed by authors, it is more facile to reduce than an aryl chloride so

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• -aryl-substituted pyrroles 55 in moderate to good yield. In addition, the method could tolerate a wide range of functional groups, such as phenolic hydroxy, aryl bromide, ester, terminal olefin, aryl chloride, and silyl-protected alcohol moieties. Furthermore, both aromatic and aliphatic nitriles

Photoredox catalysis in nickel-catalyzed C–H functionalization

• Lusina Mantry,
• Rajaram Maayuri,
• Vikash Kumar and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143

• . Notably, the photocatalytic conditions proved suitable for the benzylic C(sp3)−H and unactivated alkane cyclohexane C‒H arylations. The catalytic cycle is proposed to involve the oxidative addition of nickel(0) 4-IV into an aryl chloride 8a to form nickel(II) intermediate 4-V (Figure 4) [56]. The SET

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Water-soluble SNS cationic palladium(II) complexes and their Suzuki–Miyaura cross-coupling reactions in aqueous medium

• Alphonse Fiebor,
• Richard Tia,
• Banothile C. E. Makhubela and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1859–1870, doi:10.3762/bjoc.14.160

• . While activated aryl chloride 21f reacted with boronic acids possessing either electron-donating or electron-withdrawing groups to provide the corresponding biaryls in reasonable yields, to our dismay the reaction of inactivated aryl chlorides led to the recovery of starting materials (Table 3, entries

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• quantitative yields were observed when aryl chloride coupling was performed with arylboronic acids. This is indeed remarkable as aryl chlorides are generally not as reactive as aryl bromides or aryl iodides. Lipshutz and Ghorai developed a micellar system called PQS to perform aldol reactions in water [25]. As

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

• Marcus Baumann,
• Ian R. Baxendale and
• Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

• base and the ethyl cyanoacetate (10) being combined (note this was an exothermic process) before meeting a solution of the aryl chloride 9 and entering the ACR which was agitated at 8 Hz (Scheme 3). In an attempt to intensify the process and with the specific aim of reducing the amount of solvent in

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

• tubular reactor at 100 °C and 10 min residence time. An acetone and water mixture is used as solvent and the reactor is pressurized at 100 psi using a back pressure regulator. The resulting aryl chloride is obtained in 97% yield. The excess HCl is then quenched with NaOH and the process stream is passed

• through the membrane separator. The outlet pressure of the aqueous stream was maintained at 2 psi pressure resulting in a perfect separation. The aryl chloride is further reacted with piperazine (1.5 equiv) to obtain 1-(diphenylmethyl)piperazine in 92% yield. The optimum conditions were 150 °C, 45 min

• , and 250 psi. The alcohol substrate is then reacted with HCl in a tubular reactor in parallel to get the corresponding aryl chloride. The temperature range was 60–120 °C for different substrates whereas the residence time and pressure were maintained at 15 min and 100 psi, respectively. The excess HCl

Transition-metal-catalyzed synthesis of phenols and aryl thiols

• Yajun Liu,
• Shasha Liu and
• Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

• was further reduced by Zn/HCl in the following step to provide aryl thiols (Scheme 57). Their developed protocol could convert aryl bromide, aryl chloride and aryl trifluoromethanesulfonate to the corresponding aryl thiols in moderate to excellent yields. In comparison to palladium catalysts, copper

The reductive decyanation reaction: an overview and recent developments

• Jean-Marc R. Mattalia

Beilstein J. Org. Chem. 2017, 13, 267–284, doi:10.3762/bjoc.13.30

• while with photoactivated 78 such substrates afforded complex mixtures (see below). Contrary to the reductive decyanation with Bu3SnH [115], the NHC borane reduces the α-cyanoester 72g to 73g while the aryl chloride and bromide moieties are preserved (73h,i). The use of a 5-hexenyl radical probe led to

Highly bulky and stable geometry-constrained iminopyridines: Synthesis, structure and application in Pd-catalyzed Suzuki coupling of aryl chlorides

• Yi Lai,
• Zhijian Zong,
• Yujie Tang,
• Weimin Mo,
• Nan Sun,
• Baoxiang Hu,
• Zhenlu Shen,
• Liqun Jin,
• Wen-hua Sun and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 213–221, doi:10.3762/bjoc.13.24

• activities in the coupling reaction of aryl chlorides. Keywords: aryl chloride; geometry-constrained; iminopyridyl; palladium; Suzuki; Introduction Palladium-promoted C–C coupling reactions are recognized as one of the most powerful tools in organic syntheses, pharmaceutical processes and biological

• , it is still not favored for the cheaper and more widely available aryl chloride substrates. For C–Cl bond activation, the major efforts have focused on using extraordinarily electron-rich ligands to promote the oxidative addition. We assumed that the coupling of aryl chlorides could also be furnished

• , entry 11), which are usually regarded as reluctant substrates due to the sluggish oxidative addition of Pd(0) to aryl chlorides, proceeded successfully with moderate yields. Heterocyclic aryl chloride, for example, 2-chloropyridine, was also well tolerated and 84% isolated yields was obtained (Table 4

Comparison of the catalytic activity for the Suzuki–Miyaura reaction of (η⁵-Cp)Pd(IPr)Cl with (η³-cinnamyl)Pd(IPr)(Cl) and (η³-1-t-Bu-indenyl)Pd(IPr)(Cl)

• Patrick R. Melvin,
• Nilay Hazari,
• Hannah M. C. Lant,
• Ian L. Peczak and
• Hemali P. Shah

Beilstein J. Org. Chem. 2015, 11, 2476–2486, doi:10.3762/bjoc.11.269

• added 950 μL of a MeOH stock solution, containing 0.5263 M aryl chloride, 0.5525 M boronic acid, 0.5789 M KOt-Bu and 0.2632 M naphthalene. The vial was then heated using an aluminum block heater set to 25 °C. After thermal equilibration, the reaction was initiated via the addition of 50 μL of the

• needle. To the vial was added 950 μL of a MeOH stock solution, containing 0.5263 M aryl chloride, 0.5525 M boronic acid and 0.2632 M naphthalene. The vial was then heated using an aluminum block heater set to 25 °C. After thermal equilibration, the reaction was initiated via the addition of 50 μL of the

Half-sandwich nickel(II) complexes bearing 1,3-di(cycloalkyl)imidazol-2-ylidene ligands

• Johnathon Yau,
• Kaarel E. Hunt,
• Laura McDougall,
• Alan R. Kennedy and
• David J. Nelson

Beilstein J. Org. Chem. 2015, 11, 2171–2178, doi:10.3762/bjoc.11.235

• investigated. These experiments suggest that the ICy and IDD complexes are indeed slightly better catalysts for the cross-coupling of more challenging electrophiles. However, extension of these studies to 4-chloroanisole which is a challenging and electron-rich aryl chloride substrate, led to disappointing

An improved procedure for the preparation of Ru(bpz)₃(PF₆)₂ via a high-yielding synthesis of 2,2’-bipyrazine

• Danielle M. Schultz,
• James W. Sawicki and
• Tehshik P. Yoon

Beilstein J. Org. Chem. 2015, 11, 61–65, doi:10.3762/bjoc.11.9

• -halopyrazines are summarized in Table 1. Initial exploratory experiments using 2-chloropyrazine as the substrate gave quite poor yields using either organic or inorganic bases (Table 1, entries 1 and 2). Speculating that oxidative addition into the aryl chloride bond might be problematic in this coupling

• bipyridyl ligands that have been used to prepare strongly photooxidizing metal–polypyridyl complexes [32][33][34][35][36]. In each case, the requisite aryl iodides are either commercially available or can be easily synthesized by Finkelstein displacement of the aryl chloride with NaI [37]. Finally, we

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

Palladium(II)-catalyzed Heck reaction of aryl halides and arylboronic acids with olefins under mild conditions

• Tanveer Mahamadali Shaikh and
• Fung-E Hong

Beilstein J. Org. Chem. 2013, 9, 1578–1588, doi:10.3762/bjoc.9.180

• subjected to cross-coupling to produce the corresponding 1,2-disubstituted olefins. The results are summarized in Table 2. Both aryl bromide and aryl iodide performed well (Table 2, entries 1 and 2) under these conditions. However, the aryl chloride was found to be less reactive giving the corresponding

Controlled synthesis of poly(3-hexylthiophene) in continuous flow

• Helga Seyler,
• Jegadesan Subbiah,
• David J. Jones,
• Andrew B. Holmes and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2013, 9, 1492–1500, doi:10.3762/bjoc.9.170

• affect the polymerization in batch reactions despite the possibility that the aryl chloride solvent might participate in the Kumada reaction. Apparently, the reactivity of aryl chloride is significantly lower than that of aryl bromide under these reaction conditions. With the catalytic activity of Ni

N-Heterocyclic carbene–palladium catalysts for the direct arylation of pyrrole derivatives with aryl chlorides

• Ismail Özdemir,
• Nevin Gürbüz,
• Nazan Kaloğlu,
• Öznur Doğan,
• Murat Kaloğlu,
• Christian Bruneau and
• Henri Doucet

Beilstein J. Org. Chem. 2013, 9, 303–312, doi:10.3762/bjoc.9.35

• , 51.60; H, 4.61; N, 6.37. General Procedure for direct arylations As described in [47], in a typical experiment, the aryl chloride (1 mmol), heteroaryl derivative (2 or 4 mmol) (see Table 1–5) and KOAc (2 mmol) were introduced in a Schlenk tube, equipped with a magnetic stirring bar. The Pd complex (0.01

• conversion of the aryl chloride. The solvent was removed by heating of the reaction vessel under vacuum and the residue was charged directly onto a silica-gel column. The products were eluted by using an appropriate ratio of diethyl ether and pentane. Examples of pyrrole-containing bioactive compounds

N-Heterocyclic carbene–palladium(II)-1-methylimidazole complex catalyzed Mizoroki–Heck reaction of aryl chlorides with styrenes

• Ting-Ting Gao,
• Ai-Ping Jin and
• Li-Xiong Shao

Beilstein J. Org. Chem. 2012, 8, 1916–1919, doi:10.3762/bjoc.8.222

• ) as the ionic liquid. Keywords: aryl chloride; Mizoroki–Heck reaction; N-heterocyclic carbene; palladium complex; synthetic method; Introduction The palladium-catalyzed reaction between organic halides and alkenes, the Mizoroki–Heck reaction, is one of the most versatile methods for the formation of

Synthesis of dihydrophenanthridines by a sequence of Ugi-4CR and palladium- catalyzed intramolecular C-H functionalization

• Florence Bonnaterre,
• Michèle Bois-Choussy and
• Jieping Zhu

Beilstein J. Org. Chem. 2008, 4, No. 10, doi:10.3762/bjoc.4.10

• , ether, heterocyclic nuclei such as pyridine 1i are tolerated. The aryl chloride function survived under the present conditions leading to dihydrophenanthridine 1g and 1k in yields of 74% and 88% (two regioisomers), respectively. The presence of a chlorine atom in 1g and 1k provided a handle for further

A convenient catalyst system for microwave accelerated cross- coupling of a range of aryl boronic acids with aryl chlorides

• Matthew L. Clarke,
• Marcia B. France,
• Jose A. Fuentes,
• Edward J. Milton and
• Geoffrey J. Roff

Beilstein J. Org. Chem. 2007, 3, No. 18, doi:10.1186/1860-5397-3-18

• biaryl synthesis and is widely applied in organic chemistry. [1][2][3][4][5][6] In the last 10 years, there has been intense research interest in Suzuki reactions of aryl chloride substrates since these substrates are cheaper and more widely available than aryl bromides. A range of catalysts now exist

• for aryl chloride activation, including diphosphine-Pd catalysts,[7] mono-phosphine Pd catalysts, [8][9] cyclometallated Pd precursors,[10] and potentially hemi-labile bidentate ligands. [11][12][13][14][15] Some years ago, we demonstrated that the palladium complexes formed from the amine-phosphine

• small number of these catalyst systems have been found to deliver microwave accelerated aryl chloride cross-coupling, and in the course of another project, we discovered that the Pd/dcpmp catalyst system was just such a catalyst. [27] This has led us to investigate cross-coupling of aryl chlorides with