Stifle coupling reaction

This oxazinonc route can be used to obtain bisaryl glycines by a version of the Stifle coupling reaction (equation III). 

Polyurea-encapsulated palladium catalysts promote the phosphine-free Mizoroki-Heck reaction, which results in a high yield of cinnamates 46 (Scheme 86). The catalyst, which is easily recovered by filtration, is also applicable to the Suzuki-Miyaura and Stifle coupling reactions. 

SCHEME 12.30 Different leaving groups in the Stifle coupling reaction. 

Recent contributions from Vogel s group have shown that, under CO atmosphere and in the presence of Pd2(dba)3 and Ph3As, 1-stannyl glycals can be carbonylated and coupled to organic halides (Scheme 6a),38 or vinyl triflates (Scheme 6b),39 in carbonylative Stifle cross-coupling processes.40 Also of interest is the palladium catalyzed cross-coupling reaction of... 

For a listing of earlier reviews of the Negishi, Suzuki, Stifle, Sonogashira and other Pd-catalyzed cross-coupling reactions, see E. Negishi, in Chap. III.l of Reference 1, pp. 215-227. 

Furane derivatives, like pyrroles, couple effectively with acetylenes. In case both the a-, and / -position are available for the reaction, like in the case of 4,5-dibromo-furfural in 6.45., the cross-coupling takes place preferentially in the former position65 The observed selectivity is in line with other palladium catalyzed transformations of dihalofuranes, such as their Stifle coupling.66... 

Recently, Li successfully conducted the Suzuki and Stifle reactions on the pyrazine ring of 3-bromoquinoxalin-2-ylamines [51]. Indolylquinoxaline 92 was obtained from the union of 3-bromoquinoxalin-2-ylamine 90 and 1 -phenyIsulfonyl-2-tri-n-butylstannyl- 1/Tindole (91). A wide variety of heterocyclic stannanes bearing various functional groups underwent Stifle coupling with 90 under the same conditions to give the corresponding adducts in 72-98% yields. 

The BSMA amide framework has been shown to be unaffected under the conditions of either the Suzuki or the Stifle cross-coupling reactions.137,152,300... 

As well as labelling reagents permanently fluorous, Curran has also labelled substrates temporarily fluorous for multiplex synthesis. For example, a series of fluorous aryl tin substrates were prepared (Fig. 8) and used as variable pieces of a small library of Stifle couplings [86-88]. A mixture of tin reactant (32a-d, 1.2 equivalents), halide or triflate (35a-e, 2 mmol, 1 equivalent), PdCl2(PPh3)2 (2 mol%) and LiCl (3 equivalents) in THF/DMF (1/1,1 cm3) was heated at 80°C for 22 h. The reactions were carried out in groups of five by reacting one tin reactant with all five partners in separate vials simultaneously. After evaporation of the solvent, the crude... 

Stille reactions have also shown to be suitable for these flash heating conditions, and rapid and successful Stifle couplings were reported by Hallberg and Larhed in 1996 [Equation (5.3.21)]. ... 

The Stifle-Kelly reaction is a variant of the Stifle coupling where an organodihalide undergoes an intramolecular reaction in the presence of hexamethylditin and a palladium catalyst. 

Fluorous-phase soluble h < acryloxysuccinimide-containinj hence Wilkinson catalyst analog Miscellaneous reactions. solvents while employing a fl diaryl diselenide used to assist t A multicomponent coupling and rapid Stifle couplings are with microwave irradiation. 

In similar manner, hexaalkyldistannanes allow the homo-coupling reactions of aryl iodides, bromides [104] and triflates [105] to the symmetrical biaryls. First, the aryltrialkylstannane is generated by reaction of the aryl halides with Me6Sn2 or -Bu6Sn2, followed by the in situ Stifle reaction with an excess of electrophilic reactant, since both reactions are catalysted by the same complexes and proceed at comparable reaction rates. For instance, 2-naphthyl triflate (165) was coupled to 2,2 -binaphthalene (166) in 69% yield [105], respectively. Scheme 22. 

M. Luong, C.E. Domini, G.F. Silbestri, A.B. Chopa, Ultrasound-assisted synthesis of benzophenones by Stifle cross-coupling reactions. Optimization via experimental design, J. Orgmetal. Chem. 723 (2013) 43-48. 

---