Design and synthesis of condensed thienocoumarins by Suzuki–Miyaura reaction/lactonization tandem protocol

Microwave-assisted synthesis of 3-aminobenzo[b]thiophene scaffolds for the preparation of kinase inhibitors

“…57 In an alternative approach, our success in the microwaveassisted synthesis of 10 was adapted to incorporate an amino group at C-3, amenable by diazotization chemistry to provide efficient access to 3-bromobenzothiophene 13. The cyclocondensation of methyl thioglycolate with 2-nitrobenzonitriles under basic conditions has been established by Beck, [58][59][60] and adapted methods with halide displacement have also been reported. [61][62][63][64] By switching the base from NaOMe 61 to Et 3 N 63 and heating either 5-bromo-2-fluorobenzonitrile (14a) or 2-fluoro-5-nitrobenzonitrile (14b) and methyl thioglycolate gave the corresponding 3-aminobenzothiophene 5a,b in very high yield (Scheme 3), e.g.…”

“…Purification by flash column chromatography on silica gel, eluting with light petroleum-EtOAc (9 : 1), gave the title compound (60). To a solution containing 5-bromo-2-fluorobenzonitrile (14a) (3.0 g, 15.0 mmol), Pd(PPh 3 ) 2 Cl 2 (1.0 g, 1.5 mmol) and trans-2-cyclopropylvinylboronic acid pinacol ester (3.7 mL, 18 mmol) in DME/EtOH/H 2 O (7 : 2 : 3) (50 mL) was added aqueous Na 2 CO 3 solution (1 M; 27 mL).…”

Synthetic Routes to Coumarin(Benzopyrone)-Fused Five-Membered Aromatic Heterocycles Built on the α-Pyrone Moiety. Part 1: Five-Membered Aromatic Rings with One Heteroatom

“…The Suzuki–Miyaura cross coupling of bromoarylcarboxylates and o -hydroxy(methoxy)arylboronic acids is one of the methods that plays an important role in the preparation of 4 H -thieno[2,3- c ] 91 and 4 H -thieno[3,4- c ]benzopyran-4-ones 92 ( Scheme 26 ) [ 81 , 82 , 83 ].…”

“…), DME, H 2 O, MW 125 °C, 15 min, 86% yield; (b) i: Pd(PPh 3 ) 4 (5 mol %), K 3 PO 4 (1.5 equiv. ), 1,4-dioxane, 90 °C, 4 h; ii: (a) BBr 3 , CH 2 Cl 2 , (b) KO t Bu, H 2 O, five outputs with 75%–81% yield [ 83 ].…”

Suzuki–Miyaura Coupling Reactions of Fluorohalobenzenes

“…40,[43][44][45][46][47] In recent years, our group has studied Suzuki-Miyaura reactions of polyhalogenated substrates. [48][49][50][51][52][53][54][55] An interesting concept for the synthesis of fluorinated arenes relies on selective Suzuki-Miyaura reactions of fluorinated starting materials (building block strategy). In this article, we give a personalized Account on this chemistry.…”