Mizoroki-Heck type arylation of alkenes using aroyl chlorides under base-free conditions

The Mizoroki-Heck type arylation of alkenes with aroyl chlorides accompanied by decarbonylation efficiently proceeds in the presence of a palladium catalyst system, PdCl₂(PhCN)₂/(PhCH₂)Bu₃NCl, even without adding any base. The products can be isolated by a very simple procedure.     

Remarkable regioselectivity in microwave-enhanced palladium-catalyzed allylation reaction involving allyltrifluoroborates and aryl halides

An unprecedented cross-coupling reaction of potassium allyltrifluoroborates and aryl halides to the corresponding trans-β-methylstyrenes in the presence of PdCl₂(d^tbpf) catalyst under microwave heating was developed.     

Sonogashira cross-coupling reactions of aryl chlorides with alkynes catalysed by a tetraphosphine-palladium catalyst

A range of aryl chlorides undergoes cross-couplings with alkynes in good yields in the presence of [PdCl(C₃H₅)]₂/cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as catalyst. A variety of aryl chlorides such as chloroacetophenone, chlorobenzonitrile, chloronitrobenzene, chloroanisole or chlorotoluene have been used successfully. The reaction also tolerates several alkynes such as phenylacetylene, dec-1-yne, ethynylcyclohexene or alk-1-ynols. Furthermore, this catalyst can be used at low loading with some substrates.     

Copper-catalyzed cross-coupling reactions of non-activated primary,secondary or tertiary alkyl chlorides with phenylmagnesium bromide

Efficient copper-catalyzed cross-coupling reactions of non-activated alkyl chlorides, including primary, secondary, and tertiary alkyl chlorides, with phenyl Grignard reagents were achieved. Preparation of phenylmagnesium bromide in 2-methyltetrahydrofuran is critical for the success of the reaction. This protocol expands the synthetic toolbox for the construction of CC bonds of non-activated primary, secondary, and tertiary alkyl chlorides via copper-catalyzed cross-coupling.     

Atom-efficient cross-coupling reactions of triarylbismuths with acyl chlorides under Pd(0) catalysis

The atom-efficient cross-coupling reaction of triarylbismuths with a variety of aliphatic, aromatic, and hetero-aromatic acyl chlorides was demonstrated to afford high yields of cross-coupled ketones under palladium catalysis. The corresponding cross-coupling reaction with diacid chlorides also furnished bis-coupled ketones in good yields.     

An atom-efficient palladium-catalyzed cross-coupling reaction of triarylbismuths with acid chlorides: synthesis of diaryl and alkyl aryl ketones

The cross-coupling reaction of triarylbismuths with acid chlorides using a catalytic amount of PdCl₂/PPh₃ afforded the corresponding ketones in high yields. The reactions of aromatic and aliphatic acid chlorides occurred with atom efficiency, as 3 equiv of acid chlorides coupled effectively with 1 equiv of triarylbismuths to yield 3 equiv of the corresponding diaryl and alkyl aryl ketones.     

Synthesis of N-aryl trifluoromethylarylketoimines by palladium-catalyzed Suzuki coupling reaction of N-aryltrifluoroacetimidoyl chlorides with aryl boronic acids

A highly efficient Suzuki reaction between N-aryltrifluoroacetimidoyl chlorides and aryl boronic acids using Pd(PPh₃)₄ as a catalyst has been developed. This route allows for selective synthesis of N-aryl trifluoromethylarylketoimines in high yields under mild reaction conditions.     

First cross-coupling reaction of potassium aryltrifluoroborates with organic chlorides in aqueous media catalyzed by an oxime-derived palladacycle

Potassium aryltrifluoroborates are cross-coupled with aryl and heteroaryl chlorides using a 4-hydroxyacetophenone oxime-derived palladacycle as precatalyst, K2CO3 as base, and TBAB as additive in refluxing water under conventional and microwave heating affording the corresponding biphenyls under phosphine-free conditions. For the arylation of allyl and benzyl chlorides, KOH is used as base in acetone-water (3:2) at rt or 50 degrees C using 0.1 mol % Pd loading providing allylbenzenes and diarylmethanes, respectively.     

Stereo- and regiospecific four-molecule reaction of aroyl chlorides with iso-pentylene: direct formation of (E)-β,γ-unsaturated carbonyl compounds promoted by samarium metal in DMF

Promoted by samarium metal in DMF, aroyl chlorides react readily with iso-pentylene in a four-molecule manner, which offers an efficient stereo- and regiospecific synthesis of (E)-β,γ-unsaturated carbonyl compounds and also provides a facile method for the construction of monoterpene skeleton. The reaction is an additional example of organic reactions mediated by direct use of unactivated metallic samarium.     

Pd-catalyzed cyanation of benzyl chlorides with nontoxic K4[Fe(CN)6]

Non-toxic K₄[Fe(CN)₆] was demonstrated to be effective as a green cyanating agent for the cyanation of alkyl halides using PPh₃/Pd(OAc)₂ as a catalyst system. The presented method allowed a series of benzyl chlorides to be smoothly cyanated in up to 88% yield. In order to avoid or suppress the deactivation of the catalyst, the reaction was required to be performed in a stringent inert ambiance.     

A new application of (polyfluoroorgano)trifluoroborate salts: the palladium-catalysed cross-coupling reaction with substituted benzenediazonium tetrafluoroborates

For the first time (polyfluoroorgano)trifluoroborate salts, namely K[C₆F₅BF₃], K[C₆HF₄BF₃] (all three isomers), K[3,4,5-C₆H₂F₃BF₃], and K[CF₂CFBF₃] were principally applied as reagents to Pd-catalysed cross-coupling reactions. A series of polyfluorinated biphenyls C₆H_5−nF_n-C₆H₄X-4′ were obtained from K[C₆H_5−nF_nBF₃] and the substrates [4-XC₆H₄N₂][BF₄] in the presence of Pd catalysts. The influence of the number and the position of the fluorine atoms in the (polyfluorophenyl)trifluoroborate salts on the reactivity in the coupling reaction was elucidated. In addition to (polyfluorophenyl)trifluoroborate salts, the cross-coupling was expanded to a first example of a perfluoroalkenyl reagent. K[CF₂CFBF₃] reacted with [4-FC₆H₄N₂][BF₄] and formed CF₂CF-C₆H₄F-4.     

Effective biaryl compound synthesis using cross-coupling reaction with nickel complexes coordinated by diaminophosphine ligands

The cross-coupling reaction of aryl halides and aryl Grignard reagents was effectively catalyzed by the diaminophosphine complex catalysts and the reaction was much faster than that catalyzed by aminophosphine complexes and the nickel complexes were more active than palladium complexes. Various biaryl compounds were easily prepared by the reaction with nickel diaminophosphine catalysts.     

Potassium selenocyanate as an efficient selenium source in C-Se cross-coupling catalyzed by copper iodide in water

An efficient and conceptually new protocol for C-Se cross coupling of potassium selenocyanate with aryl halides via copper-catalyzed cascade reaction has been developed in water. Utilizing this protocol, a variety of aryl and heteroaryl halides were reacted with potassium selenocyanate to afford the corresponding diaryl selenides in moderate to good yields.     

An efficient palladium-catalyzed coupling reaction of lithium alkynyltriisopropoxyborates with acid chlorides: a new access to synthesis of conjugated ynones

An efficient palladium-catalyzed protocol for the synthesis of ynones from lithium alkynyltriisopropoxyborates with acid chlorides under mild neutral conditions.     

Determination of trace organic chlorides in hydrogen for fuel cell vehicles by gas chromatography coupled with ion mobility spectrometry

A method for the determination of organic chlorides in hydrogen for fuel cell vehicles by gas chromatography coupled with ion mobility spectrometry was established. Organic chlorides were separated by a non-polar gas chromatography column and detected in the negative ion mode of the ion mobility spectrometer. The effect of operating parameters of ion mobility spectrometer including drift gas flow rate and drift tube temperature on sensitivity and resolution were evaluated. Under the optimized conditions, the detection limits of seven organic chlorides were from 0.65 to 6.73 nmol/mol, which met the requirement of detection for the specification limit of 50 nmol/mol of total halogen impurities in hydrogen for fuel cell vehicles. Compared with gas chromatography-mass spectrometry, and gas chromatography coupled with electron capture detector under the same gas chromatography conditions, gas chromatography coupled with ion mobility spectrometry method demonstrated higher sensitivity for detection of organic chlorides under study. Based on the portability of the device and its detection capabilities, gas chromatography coupled with ion mobility spectrometry has the potential to perform online detection of impurities in hydrogen for fuel cell vehicles.     

A practical synthesis of aryl sulfones via cross-coupling of sulfonyl hydrazides with aryltriazenes using copper/ionic liquid combination

A new and efficient approach adopting copper-catalyzed cross-coupling of sulfonyl hydrazides with aryltriazenes has been developed to synthesize aryl sulfones using Brønsted acidic ionic liquid as promoter under ambient conditions. The process employs stable and easy to handle reacting partners, and is endowed with broad substrate scope.     

Ni-catalyzed cross-coupling reaction of aryl chlorides with arylboronic acids in IPA without using a reducing reagent

The coupling reaction of aryl chlorides with arylboronic acids was successfully performed in isopropanol (IPA) by using [NiCl(Ph₂PCH₂CH₂OH)₂(H₂O)]Cl (5), a cationic Ni(II)-complex, as a precatalyst in the absence of a reducing agent. The coupling reaction proceeded smoothly under mild conditions to provide biaryls in satisfactory to excellent yields, and formation of the undesired dechlorination products of aryl chlorides was completely prevented.     

Study of homo- and cross-coupling competition in the reaction of triarylbismuth(V) dicarboxylates with methyl acrylate in the presence of a palladium catalyst

Triarylbismuth(V) derivatives Ar₃Bi(O₂CR)₂ (Ar = Ph, m-Tol, p-Tol; R = H, Me, Et, n-Bu, t-Bu, n-C₅H₁₁, CF₃, CH₂Cl, CCl₃, Ph) were prepared in good to excellent yields by reaction of Ar₃Bi with equimolar amounts of t-BuOOH in the presence of an acid. These compounds were tested in the C-arylation reaction of methyl acrylate, as a model substrate, in the presence of palladium catalyst (4 mol%). It was found that triphenylbismuth dicarboxylates are very active phenylating agents under mild conditions (20 °C). The effect of the carboxylic group, the effect of the nature of the palladium catalyst and the effect of oxygen on the reactivity of the organobismuth compounds and on the selectivity of the C-arylation reaction were studied. Methyl cinnamate, the C-phenylation product, and biphenyl, the homo-coupling by-product, were obtained in all cases. Triphenylbismuth divalerate Ph₃Bi(O₂CBu)₂ is the most reactive compound among the triphenylbismuth dicarboxylates studied.     

Suzuki-Miyaura cross-coupling reaction of aryl bromides and chlorides with phenylboronic acid under aerobic conditions catalyzed by palladium complexes with thiosemicarbazone ligands

For the first time, palladium complexes with salicylaldehyde thiosemicarbazones were applied as catalyst precursors to the Suzuki-Miyaura reaction. These air and moisture stable phosphine-free systems efficiently catalyze the cross-coupling of aryl bromides and chlorides (from electron rich to electron poor) with phenylboronic acid in DMF/H₂O at 100 °C for 24 h, using Na₂CO₃ as base, without addition of free ligand or any promoting additive, and under aerobic conditions no significant homocoupling of phenylboronic acid to unsubstituted biphenyl was observed.