100103-94-4

Upstream product

• 6553-96-4 2,4,6-triisopropylphenylsulfonyl chloride 
• 100-42-5 styrene 
• 39085-59-1 trisylhydrazine 
• 24249-82-9 2,4,6-triisopropylbenzaldehyde 
• 111773-08-1 cis-2,4,6-triisopropylstilbene 
• 21524-34-5 2,4,6-triisopropyl-1-bromobenzene 

Downstream Products

• 49623-71-4 2,4,6-triisopropylbenzoic acid 
• 65-85-0 benzoic acid 

Relevant academic research and scientific papers

Controlling olefin isomerization in the heck reaction with neopentyl phosphine ligands

The use of neopentyl phosphine ligands was examined in the coupling of aryl bromides with alkenes. Di-tert-butylneopentylphosphine (DTBNpP) was found to promote Heck couplings with aryl bromides at ambient temperature. In the Heck coupling of cyclic alkenes, the degree of alkene isomerization was found to be controlled by the choice of ligand with DTBNpP promoting isomerization to a much greater extent than trineopentylphosphine (TNpP). Under optimal conditions, DTBNpP provides high selectivity for 2-aryl-2,3-dihydrofuran in the arylation of 2,3-dihydrofuran, whereas TNpP provided high selectivity for the isomeric 2-aryl-2,5-dihydrofuran. A similar complementary product selectivity is seen in the Heck coupling of cyclopentene. Heck coupling of 2-bromophenols or 2-bromoanilides with 2,3-dihydrofurans affords 2,5-epoxybenzoxepin and 2,5-epoxybenzazepins, respectively.

PALLADIUM CATALYST, METHOD FOR ITS PREPARATION AND ITS USE

The invention relates to palladium(0)-tris{tri-[3,5-bis(trifluoromethyl)-phenyl]-phosphine} complex of formula (I), as well as to its preparation and use. This compound is outstandingly stable, and can be used as catalyst with excellent results.

Oxidative Mizoroki-Heck-type reaction of arylsulfonyl hydrazides for a highly regio- and stereoselective synthesis of polysubstituted alkenes

A useful source: Arylsulfonyl hydrazides have been identified as synthetically useful aryl sources for the Pd(OAc)2 catalyzed oxidative Mizoroki-Heck-type reaction under molecular oxygen to provide a convenient access to polysubstituted alkenes in a highly regio- and stereoselective manner (see scheme). The reaction well tolerates various functional groups such as alkoxy, halo, alcohol, carboxylic acid, ester, amide, sulfonamide, and sulfone. Copyright

A NEW PALLADIUM CATALYST, METHOD FOR ITS PREPARATION AND ITS USE

The invention relates to palladium(0)-tetrakis{tri-[3,5-bis(trifluoromethyl)- phenylj-phosphine} complex of formula (I), as well as to its preparation and use. This compound is outstandingly stable, and can be used as catalyst with excellent results.

A heteroleptic palladium(II) complex containing a bidentate carbene/amido ligand and 3-(trifluoromethyl)-5-(2-pyridyl)pyrazolate: Fast catalyst activation in the heck coupling reaction

A multicomponent reaction between PdCl2, fppzH, and [LH 1H2]Cl in the presence of K2CO3 (L = bidentate amido/carbene; fppzH = 3-(trifluoromethyl)-5-(2-pyridyl)pyrazole) allows the preparation of PdL(fppz) in good yield. The analogous platinum complex, however, needs to be prepared by a two-step procedure. The new palladium(II) and platinum(II) complexes were characterized by 1D and 2D NMR spectroscopy, X-ray crystallography, electrospray ionization mass spectrometry, and elemental analyses. X-ray photoelectron spectroscopy indicates the high electron richness of the palladium atoms in PdL(fppz). These palladium complexes are efficient in catalyzing Heck coupling reactions with challenging aryl halide substrates. The catalyst activation in PdL(fppz) is significantly faster than that in cis-PdL2. A mere 0.5 mol % of palladium loading is enough to afford a 82% yield of coupled product from 4-chloroanisole and styrene in 24 h.

Efficient heck reactions catalyzed by palladium(0) and -(II) complexes bearing n-heterocyclic carbene and amide functionalities

A palladium(0) NHC complex Pd0(LH1)2(MA) (MA = maleic anhydride) was prepared from the amide-imidazolium salt [LH 1H2]Cl (H1 = NH proton; H2 NCHN proton). The X-ray diffraction studies confirmed that a η2-MA ligand and two monodentate NHC ligands with the H1 protons remaining intact are coordinated. These NH protons are involved in intra- or intermolecular hydrogen bonds stabilizing the solid-state structure. Degradation of Pd(LH1)2(MA) in air leads to the formation of the chelate complex trans-PdIIL2 and other unidentified products. Negative-ion electrospray mass spectrometry revealed some intriguing Pd(0) species, including a 14-electron [Pd0L]- species that bears only a bidentate NHC/amido ligand. The anionic amido group imparts a high electron density on a palladium center, as shown by X-ray photoelectron study. The palladium(0) precatalyst is highly efficient in catalyzing Heck reactions with activated aryl chlorides in ionic liquid. For deactivating aryl chlorides and bulky aryl bromides, cis-PdIIL2 is more effective. A range of Heck-coupled products can be prepared by Pd 0(LH1)2(MA) and cis-PdIIL 2. The latter complex also successfully mediates one-pot sequential Heck/Heck and Suzuki/Heck coupling reactions with 4-bromochlorobenzene as substrate.

A new efficient tetraphosphine/palladium catalyst for the Heck reaction of aryl halides with styrene or vinylether derivatives

cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C 3H5)]2 system efficiently catalyses the Heck reaction of aryl halides with styrene and vinylether derivatives. High turnover numbers can be obtained for the reaction of several aryl halides with styrene and styrene derivatives. Lower turnover numbers have been observed in the presence of vinylethers.

Regioselectice Trans-Cis Photoisomerization of m-Styrylstilbenes

Trans-cis photoisomerization of m-styrylstilbenes, i.e., 2,4,6-triisopropyl-3'-styrylstilbene (TISS), 2,4,6-trimethyl-3'-styrylstilbene (TMSS), and 3-styrylstilbene (SS), and of stilbenes, i.e., 2,4,6-triisopropylstilbene (TIS), 2,4,6-trimethylstilbene (TMS), and stilbene (S), are studied under direct or benzophenon-sensitized irradiation in hexane.Measurements of quantum yields for isomerization have revealed that although the styrylstilbene molecule bears two styryl groups, the reaction is highly regioselective, depending upon the excitation conditions and reactant structures.For example, isomerizations of trans,trans-TISS and trans,cis-TISS occured either at the 2,4,6-trisubstituted styryl side upon direct excitation or at the unsubstituted styryl side upon sensitized excitation.When the starting material carries an unsubstituted cis-styryl group, the major isomerization always occurred at this moiety by either direct or sensitized axcitation, e.g., cis,trans-TISS ---> trans,trans-TISS, cis,cis-TISS ---> trans,cis-TISS, and cis,trans-SS ---> trans,trans-SS.Furthermore, the photoisomerization of cis-SS was found to be one-way.These results are interpreted in terms of the usual "energy sink" concept: the excited-state energies (ES and ET) of the stilbene chromophores depend on molecular distortion in a subtle manner.It seems that an extremely rapid cis ---> trans isomerization rate of the unsubstituted cis-styryl group is also responsible for the observed preferential photoisomerization of this group.Finally, the cis,cis isomers of TISS, TMSS, and SS underwent upon sensitized excitation minor but substantial one-photon two-double-bond isomerization (cis,cis ---> trans,trans) in addition to major one-double-bond isomerization.This reaction is not common, since the two isomerizing double bonds are cross-conjugated.