Direct electrophilic borylation using Y(2)BCl (Y(2) = Cl(2) or o-catecholato) with equimolar AlCl(3) and a tertiary amine has been applied to wide range of arenes heteroarenes. In situ functionalization the ArBCl(2) products is possible TMS(2)MIDA, afford bench-stable easily isolable MIDA-boronates in moderate good yields. According combined experimental computational study, activated at 20 °C proceeds through an S(E)Ar mechanism borenium cations, [Y(2)B(amine)](+), key electrophiles. For...

Electrophilic borylation using BCl₃and benzothiadiazole to direct the C–H functionalisation of an adjacent aromatic unit produces fused boracyclic materials with minimally changed HOMO energies but significantly reduced LUMO energies.

Transition metal free alkyne <italic>trans</italic>-hydroboration is achieved using strong boron electrophiles in the presence of a B–H moiety.

Hail boration! 2-Dimethylaminopyridine-ligated dihaloborocations [X2B(2-DMAP)](+) with a strained four-membered boracycle were used for the haloboration of terminal and dialkyl internal alkynes (see scheme). Esterification then provided vinyl boronate esters as useful precursors to tetrasubstituted alkenes. Following mechanistic studies, scope was expanded simply by variation amine. Pin = 2,3-dimethyl-2,3-butanedioxy.

We report the isolation and detailed structural characterization, by solid-state solution NMR spectroscopy, of neutral mono- bis-NHC adducts bis(catecholato)diboron (B2 cat2 ). The adduct undergoes thermally induced rearrangement, forming a six-membered -B-C=N-C=C-N-heterocyclic ring via C-N bond cleavage expansion NHC, whereas mono-NHC is stable. Bis(neopentylglycolato)diboron neop2 ) much more reactive than B2 giving expanded product at room temperature, demonstrating that NHCs can be very...

The reaction of 8-(trimethylsiloxy)quinoline (QOTMS) with BCl3 and (aryl)BCl2 forms QOBCl2 QOBCl(aryl). subsequent addition stoichiometric AlCl3 follows one two paths, dependent on the steric demands QO ligand electrophilicity resulting borenium cation. phenyl- 5-hexylthienylborenium cations, QOBPh(+) QOBTh(+), are formed, whereas QOBCl(+) is not. Instead, preferentially binds at oxygen, forming ⋅AlCl3, rather than abstracting chloride. A modest increase in around by installing a methyl...

The reaction of [Et4N][Mo(CSe)(CO)2(Tp*)}] (Tp* = hydrotris(dimethylpyrazolyl)borate) with [Ir(NCMe)(CO)(PPh3)2]BF4 results not in the anticipated isoselenocarbonyl complex [(Tp*)(CO)2Mo−CSe−Ir(CO)(PPh3)2] but rather tetranuclear bis(μ-carbido) (μ-Se2)[Ir2{C≡Mo(CO)2(Tp*)}2(CO)2(PPh3)2].

Inter-/intra-molecular electrophilic C–H borylation of C4-substituted indoles enables the formation fused polycyclic aromatic structures containing triarylborane and N-heterocyclic units.

Aber Hal(l)o: Dihalogenborkationen [X2B(2-DMAP)]+ mit 2-Dimethylaminopyridinliganden und gespanntem viergliedrigem Boracyclus wurden in der Haloborierung von terminalen internen Dialkylalkinen eingesetzt (siehe Schema). Anschließende Veresterung ergab Vinylboronatester als nützliche Vorstufen für tetrasubstituierte Alkene. Dank mechanistischer Studien ließ sich das Substratspektrum die einfach durch Variieren Amins erweitern. Pin=2,3-Dimethyl-2,3-butandioxy.

The synthesis of the enantiomer structure, 1, assigned to natural product nobilisitine A has been accomplished using enantiomerically pure cis-1,2-dihydrocatechol 4 as starting material. (1)H and (13)C NMR spectral data derived from compound ent-1 do not match those reported for product, thus suggesting its structure incorrectly assigned.

The reactions of [RuCl2(═CHPh)(PCy3)2] or [RuHCl(η-H2)(PCy3)2] with the N-heterocyclic silylene :Si(NtBuCH)2 (ISitBu) affords coordinatively unsaturated complex [RuHCl(ISitBu)(PCy3)2]. For comparative purposes, corresponding [RuHCl(IiPr)(PCy3)2] (IiPr = :C(NiPrCH)2) was obtained from and IiPr.

(NHC)2FeCl2 complexes undergo methoxide transfer in preference to aryl from [(Aryl)B(OR)3]−, while addition of ArylBY2 (Y = Cl, OR) (NHC)Fe–methoxide compounds leads only formation (NHC)BY2Aryl. The PhBCl2 (NHC)2FeX2 is introduced as a method for probing NHC dissociation iron. Two expanded ring NHCs also iron the respective complexes.

The unexpected 1,1/1,2 isomerisation of the diolate in B₂cat₂ is observed on addition Lewis bases.

The addition of organolithium reagents to an equilibrating mixture diastereomers a phosphine-stabilized 1,2-ethanediylbis(phenylarsenium triflate) containing chiral arsenic stereocenters and enantiomerically pure, atropisomeric tertiary phosphepine derived from lithiated (aR)-2,2′-dimethyl-1,1′-binaphthalene generates unequal mixtures enantiomers chelating 1,2-ethanediylbis(tertiary arsines), at arsenic, with liberation the (aRP)-phosphepine. Thus, methyllithium in diethyl ether −95 °C...

N-Arylazetidin-2-ones of the general form 1, which are readily prepared by Goldberg–Buchwald-type copper-catalyzed coupling N-unsubstituted azetidin-2-ones with relevant aryl halide or using Mitsunobu cyclization processes, undergo smooth Fries-rearrangement in triflic acid at 0–18°C to give isomeric 2,3-dihydro-4(1H)-quinolones (2). Dehydrogenation latter compounds 10% Pd on C 1.0 M aqueous sodium hydroxide/propan-2-ol mixtures ca. 82°C provides corresponding 4(1H)-quinolones (3).

The salt elimination reactions of [NEt4][Mo(CSe)(CO)2(Tp*)] ([NEt4][2], Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with a range metal halide complexes (ClMLn) have been investigated as possible route to isoselenocarbonyl [Mo(CSeMLn)(CO)2(Tp*)]. Thus the [NEt4][2] [RuCl(L)2(η-C5R5)] provide molybdenum-ruthenium derivatives [Mo{CSeRu(L)2(η-C5R5)}(CO)2(Tp*)] (L PPh3, R H 4, L CO, Me 5), both which were structurally characterised. molybdenum-iron derivative...

Synthetically straightforward conditions have been developed for the preparation of poly(bis 2,2,2-trifluoroethoxy)phosphazene with low PDI (<1.15) at high conversion (75-99%) and on a multigram scale. A combination 31P NMR GPC analyses demonstrate that molecular weight increases linearly as function monomer consumption, exhibiting first order kinetics respect to concentration up conversion. Thus, can be controlled by varying initiator (H2O) ratio.

The application of the title building blocks, 6,6-dibromobicyclo[3.1.0]hexanes and cis -1,2-dihydrocatechols, to total synthesis crinine lycorinine alkaloids is described.

The reaction of 1-chloro-2-(trimethylsilyl)-1-boracyclohexa-2,5-diene with [nBu4N]CN provides the 1-borabenzonitrile salt [nBu4N][C5H5BCN] which in turn reacts [Ru4(μ-Cl)4(η-C5Me5)4] to afford sandwich complex [Ru(η6-C5H5BCN)(η-C5Me5)]. bonding is discussed recourse crystallographic data for and

The reaction of the propargylic salt [Ph3PCH2C≡CH]PF6 with [Pt(C2H4)(PPh3)2] affords η2-allenylphosphonium [Pt(η2-CH2═C═CHPPh3)(PPh3)2]PF6 via a metal-mediated rearrangement. Isomerization complex occurs in solution to generate [Pt{η2-C(PPh3)═C═CH2}(PPh3)2]PF6, wherein allene is coordinated by internal C═C bond. Computational studies indicate that isomerization cation [Ph3PCH2C≡CH]+ allenyl species [Ph3PCH═C═CH2]+ and α-alkynyl isomer [Ph3PC≡CCH3]+ thermodynamically favorable. isomeric...

The racemic form, (±)-1, of the structure originally assigned to crinine alkaloid haemultine has been prepared for first time. A key step involved conversion compound (±)-4 into isomeric cis-C3a-arylhexahydroindole (±)-3 using a Pd0-catalysed intramolecular Alder-ene reaction. amino-alcohol (±)-2 derived from latter reacted with paraformaldehyde in presence trifluoroacetic acid give, via Pictet–Spengler reaction, target (±)-1. diastereoisomeric Mosher esters 15 and 16 obtained by coupling...

The sequential treatment of Na[H2B(mt)2] (mt = methimazolyl) with [Mo(pip)2(CO)4] (pip piperidine), [Mo(CO)3(L)3] (L NCMe, L3 η6-C7H8) and [AuCl(PPh3)] provides the diheterotrimetallic complex [Mo2Au{μ-H2B(mt)2}(CO)7(PPh3)] in which each thione group H2B(mt)2 ligand bridges two molybdenum centers, one is also involved a 3-center, 2-electron B−H−Mo interaction. This obtained directly from [Mo(CO)3(η6-C7H8)] [Au(PPh3){H2B(mt)2}] while triheterotrimetallic species [MoWAu{μ-H2B(mt)2}(CO)7(PPh3)]...

The reaction of 1-chloro-2-(trimethylsilyl)-1-boracylohexa-2,5-diene (1) with N-methylimidazole (NMI) results not in the anticipated borabenzene adduct [(NMI)→BC5H5] (3) but rather title imidazole-stabilized cyclic boronium salt [(NMI)2BC5H5SiMe3-2]Cl ([2]Cl), which represents a rare example trapped intermediate or possible tangent en route to neutral may be obtained by heating [2]Cl under vacuum.