Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

• Yuki Yamamoto,
• Yuki Konakazawa,
• Kohsuke Fujiwara and
• Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

• , Sakai, Osaka 599-8531, Japan Organization for Research Promotion, Osaka Metropolitan University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan 10.3762/bjoc.20.216 Abstract A simple and versatile synthesis of arylboronates has been achieved by using triarylbismuthines as aryl radical sources

• the generation of aryl radicals, and the subsequent reaction with bis(pinacolato)diboron afforded a variety of arylboronates in moderate to good yields. Keywords: arylboronates; bis(pinacolato)diboron; radical reactions; transition-metal-free synthesis; triarylbismuthines; Introduction Arylboronates

• variety of transition-metal-catalyzed reactions and photoredox reactions using arylboronates as aryl sources have been energetically investigated for the construction of carbon–carbon or carbon–heteroatom bonds [12][13][14][15]. The preparation of arylboronates often requires pre-functionalized substrates

Palladium-catalyzed solid-state borylation of aryl halides using mechanochemistry

• Koji Kubota,
• Emiru Baba,
• Tamae Seo,
• Tatsuo Ishiyama and
• Hajime Ito

Beilstein J. Org. Chem. 2022, 18, 855–862, doi:10.3762/bjoc.18.86

• , Japan 10.3762/bjoc.18.86 Abstract This study describes the solid-state palladium-catalyzed cross-coupling between aryl halides and bis(pinacolato)diboron using ball milling. The reactions were completed within 10 min for most aryl halides to afford a variety of synthetically useful arylboronates in

• organic materials, typically through Suzuki–Miyaura coupling [1][2][3][4][5][6][7]. The palladium-catalyzed boryl substitution of aryl halides with boron reagents, termed Miyaura–Ishiyama borylation, is an efficient method for synthesizing arylboronates with high functional group compatibility [8][9][10

• -donating and electron-withdrawing groups at the para position (1b–d) proceeded smoothly to afford the corresponding arylboronates (3b–d) in good to high yields. 4-Bromobiphenyl (1e) also underwent borylation efficiently to form the borylation product (3e) in excellent yield. We found that substrates

Total synthesis of decarboxyaltenusin

• Lucas Warmuth,
• Aaron Weiß,
• Marco Reinhardt,
• Anna Meschkov,
• Ute Schepers and
• Joachim Podlech

Beilstein J. Org. Chem. 2021, 17, 224–228, doi:10.3762/bjoc.17.22

• . Biphenyl-derived mycotoxins. Synthesis of arylboronates 6. Conditions: a) TBSCl, DMAP, imidazole, DMF, 50 °C, 4 h (96%); b) NBS, MeCN, rt, 71 h (quant.); c) NBS, MeCN, rt, 72 h (R = TBS, 96%); d) BnBr, KI, K2CO3, DMF/acetone, 70 °C, 29 h, (R = Bn, 86%); e) R = TBS: BuLi, 2-isopropoxy-4,4,5,5-tetramethyl

Efficient synthesis of 3,6,13,16-tetrasubstituted-tetrabenzo[a,d,j,m]coronenes by selective C–H/C–O arylations of anthraquinone derivatives

• Seiya Terai,
• Yuki Sato,
• Takuya Kochi and
• Fumitoshi Kakiuchi

Beilstein J. Org. Chem. 2020, 16, 544–550, doi:10.3762/bjoc.16.51

• alkyl and alkoxy substituents at the 3, 6, 13, and 16-positions was achieved based on the ruthenium-catalyzed coupling reactions of anthraquinone derivatives with arylboronates via C–H and C–O bond cleavage. The reaction sequence involving the arylation, carbonyl methylenation, and oxidative cyclization

• ][21][22][23][24][25][26][27][28][29][30][31][32][33]. In the presence of ruthenium carbonyl phosphine complexes, the reaction of aromatic ketones possessing C–H bonds or C–OR (R = alkyl) bonds with arylboronates provided C–H or C–O arylation products [21][22][23][24][25][26][27][28][29][30][31][32][33

• aryl groups at the 1, 4, 5, and 8-positions through a RuH2(CO)(PPh3)3-catalyzed C–H arylation of anthraquinone (1) with arylboronates 2 [16]. Using this method, we examined the synthesis of a tetraarylanthraquinone possessing four hexyloxy groups. When the reaction of 1 with 4-hexyloxyphenylboronate 2a

Mechanochemical borylation of aryldiazonium salts; merging light and ball milling

• José G. Hernández

Beilstein J. Org. Chem. 2017, 13, 1463–1469, doi:10.3762/bjoc.13.144

• the original study, irradiation for 18 h of a MeCN solution of aryldiazonium salts, bis(pinacolato)diboron (B2pin2, 2) and eosin Y with a 25 W visible light lamp led to the corresponding arylboronates in moderate to good yields [18]. Results and Discussion To commence, a PMMA milling jar was designed

Recent advances in copper-catalyzed asymmetric coupling reactions

• Fengtao Zhou and
• Qian Cai

Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280

• the copper/NHC-catalyzed asymmetric allylic substitution of allyl phosphates with arylboronates. Furthermore, they applied the method to the construction of quaternary carbon stereocenters with good enantioselectivity (up to 90% ee) with disubstituted allyl phosphates. The enantioselectivity was later

Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF₅-substituted phenylboronic esters and iodobenzenes

• George Iakobson,
• Junyi Du,
• Alexandra M. Z. Slawin and
• Petr Beier

Beilstein J. Org. Chem. 2015, 11, 1494–1502, doi:10.3762/bjoc.11.162

• -science [6][18][33][34][35][36][37][38], and material sciences [5][19][38][39] are emerging. Arylboronic acids and arylboronates represent versatile building blocks in organic synthesis [40]. They have found wide applications in transition metal-catalyzed cross-coupling reactions [41][42]. These boron