With aryl triflates

Haloalkynes (R—C=C—X) react with ArSnBu3 and Cul to give R—C= C—Ar. Acetylene reacts with two equivalents of iodobenzene, in the presence of a palladium catalyst and Cul, to give 1,2-diphenylethyne. 1-Trialkylsilyl alkynes react with 1-haloalkynes, in the presence of a CuCl catalyst, to give diynes and with aryl triflates to give 1-aryl alkynes. Alkynes couple with alkyl halides in the presence of Sml2/Sm. Alkynes react with hypervalent iodine compounds " and with reactive alkanes such as adamantane in the presence of AIBN. ... 

Treating 2,3-dihydrofuran 68 with aryl triflate 69 in the presence of a base and a palladium catalyst generated in situ from Pd(OAc)2 and (R)-BINAP... 

Analogously, 5-tributylstannylimidazole 29 was easily obtained from the regioselective deprotonation of 1,2-disubstituted imidazole 28 at C(5) followed by treatment with tributyltin chloride [24]. In the presence of 2.6 equivalents of LiCl, the Stille reaction of 29 with aryl triflate 30 afforded the desired 1,2,5-trisubstituted imidazole 31 with 2,6-di-tert-butyl-4-methylphenol (BHT) as a radical scavenger. Reversal of the nucleophile and electrophile of the Stille reaction also provided satisfactory results. For example, the coupling reaction of 5-bromoimidazole 33, derived from imidazole 32 via a regioselective bromination at C(5), and vinylstannane 34 produced adduct 35 [24],... 

The reaction is carried out with aryl triflates and other details such as solvent and base used are also important. Intramolecular additions of aryl halides or triflates to alkenes in a side-chain leading to cyclic compounds have been reported by Overman [24], Rather complicated ring structures can be made stereospecifically. While initially BINAP seemed the best ligand for this conversion, the number of useful ligands is increasing [25],... 

Scheme 28 Cross-coupling reaction of organobismuth alkoxides with aryl triflates...

Hypervalent organobismuth compounds 1 bearing a 2,6-pyridinedialkoxide ligand [43] were used for the cross-coupling reaction with aryl triflates (Scheme 28) [44], Phenylation using phenylbismuth compounds smoothly proceeded for the reactive... 

The similar cross-coupling reaction of compounds 1 with aryl iodides was less sensitive to the electronic nature of the substrates than that with aryl triflates i.e., electron-deficient 4 -iodoacetophenone and electron-rich 4-iodoanisole afforded the cross-coupling products in 96% and 55% yields, respectively (Scheme 29) [45]. The addition of cesium salts improved the product yields considerably. Aryl bromides were less efficient than aryl iodides, and addition of cesium salts was necessary to improve the product yields. 

Unsuccessful couplings arose when resin-bound olefin was reacted with aryl triflates (presumably reflecting the lower reactivity observed in solution) and also when resin-bound iodide was reacted with ethyl propionate, where polymerized products were observed. Interestingly, attempts at transesterification as a means to release the products were unsuccessful. The stereochemistry (i.e., cis/trans) of the products was not addressed. 

Chiral benzyl or allyl silanes 119 couple with aryl triflates to give the corresponding products having 58-99% enantioselectivities (equation 97)176-178>i 9 j le selectivity appears to be very much dependent on the reaction conditions. 

M. Regioselective arylation of benzanilides with aryl triflates of bromides under Pd catalysis. Tetrahedron Lett. 2000, 43, 2655-2658. 

Asymmetric Heck-type ary lotion.1 A catalyst prepared in situ from Pd(OAc)2 and (R)-BINAP effects a highly enantioselective arylation of 2,3-dihydrofuran with aryl triflates with diisopropylethylamine as base and benzene as solvent. Two products (2 and 3) are formed with opposite configurations. The highly enantioselective formation of the major product (2) is ascribed to a kinetic resolution step which converts the enantiomer of 2 into 3. 

Coupling of alkylsilanes with aryl triflates.3 Coupling of organosilanes with triflates is possible with fluoride ion (2 equiv.) and a Pd(0) catalyst. The striking... 

Synthesis of arylboronates via the palladium(0)-catalyzed cross-coupling reaction of tetra(alkoxy)diboranes with aryl triflates has been reported.114 The cross-coupling reaction of (RO)2B-B(OR)2 (OR = methoxy and pinacolato) with aryl triflates to give arylboronates 178-189 was carried out at 80 °C in the presence of PdCl2(dppf) (3 mol%), and KOAc (three equivalents) in dioxane. The reaction was generalized to various functional groups such as nitro, cyano, ester, and carbonyl groups (Scheme 30). 

Me2CuLi couples with a variety of alkenyl triflates (bromides, iodides) giving methyl derivatives (Table 16.1), and, in complete analogy, with aryl triflates (bromides, iodides). Occasionally, Me2CuLi also couples with alkenyl or aryl phosphates. 

It was envisioned that the attachment of a functionalized aromatic group could be done via a Buchwald-Hartwig reaction (Scheme 11). This reaction was first studied using diphenethylamine with aryl triflates and halides as model compounds. Diphenethylamine was... 

Reaction of 2,3-dihydrofuran with aryl triflate in benzene in the presence of a base and a palladium catalyst, prepared in situ from Pd(OAc)2 and 2 equivalents of (R)-BINAP, gave (R)-2-aryl-2,3-dihydrofuran (2) and a small amount of the regioisomer (5)-2-aryl-2,3-dihydrofuran (3) (Scheme 1). Table I demonstrates that the arylation reaction proceeds in extremely high enantioselectivity with a variety of aryl triflates. Particularly, almost enantiomerically pure (R)-2 was obtained with 2-naphthyl triflate and phenyl triflates bearing an electron-withdrawing substituent at the para or meta position. 

Cross-coupling reactions of areneboronic acids with aryl triflates in the presence of K3PO4 and a catalytic amount of Pd(PPh3)4 or PdCl2(dppf) in dioxane proceed with high yields. The reaction conditions are sufficiently mild that a variety of functionalized biaryls may readily be obtained (Eq. (4)) [19]. 

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