Stereoselective Fluorosulfonylation of Vinylboronic Acids for (E)-Vinyl Sulfonyl Fluorides with Copper Participation.

A practical synthetic method for the synthesis of vinyl sulfonyl fluorides through copper-promoted direct fluorosulfonylation has been developed. The reaction of the vinylboronic acids with DABSO and then NFSI is performed under mild reaction conditions. This transformation efficiently affords aryl or alkyl vinyl sulfonyl fluorides with good reaction yields, exclusive E-configuration, broad substrate scope, excellent compatibility, and operational simplicity.

Transition-Metal-Free Synthesis of Aryl Trifluoromethyl Thioethers through Indirect Trifluoromethylthiolation of Sodium Arylsulfinate with TMSCF3.

Herein, we report an indirect trifluoromethylthiolation of sodium arylsulfinates. This transition-metal-free reaction significantly provides an environmentally friendly and practical synthetic method for aryl trifluoromethyl thioethers using commercial Ruppert-Prakash reagent TMSCF3. This approach is also a potential alternative to the current industrial production method owing to facile substrates, excellent functional group compatibility, and operational simplicity.

Geometrically Selective Denitrative Trifluoromethylthiolation of ß-Nitrostyrenes with AgSCF3 for (E)-Vinyl Trifluoromethyl Thioethers.

An efficient copper(II)-promoted denitrative trifluoromethylthiolation under mild reaction conditions has been developed for vinyl trifluoromethyl thioethers to construct Cvinyl-SCF3 bonds with stable AgSCF3 as a source of the trifluoromethylthio. This reaction system tolerates a broad range of functional groups to commendably achieve a high product yield and excellent stereoselectivity of E/Z.

Living 3,4-(Co)Polymerization of Isoprene/Myrcene and One-Pot Synthesis of a Polyisoprene Blend Catalyzed by Binuclear Rare-Earth Metal Amidinate Complexes.

Mononuclear amidinate yttrium complex C4 H9 C(NR)2 Y(o-CH2 C6 H4 NMe2 )2 (R=2,6-iPr2 C6 H3 ) and a series of binuclear rare-earth metal complexes bearing a bridged amidinate ligand [(RN)2 C(CH2 )4 C(NR)2 ][RE{CH2 C6 H4 (o-NMe2 )}2 ]2 (R=2,6-iPr2 C6 H3 , RE=Y, Lu, Sc) were synthesized and fully characterized. The catalytic behavior of these complexes for (co)polymerization of conjugated dienes such as isoprene and myrcene in the presence of co-catalyst [Ph3 C][B(C6 F5 )4 ] was investigated. These catalytic systems show impressively high activity and 3,4-regioselectivity in living (co)polymerization. The binuclear bridged amidinate yttrium catalytic system not only exhibits the highest activity among the reported catalytic systems for 3,4-polymerization of isoprene but also allows the steady polymerization in a living manner from -20 to 80 °C. Compared with the dramatic drop of 3,4-selectivity for the mononuclear analogue, the binuclear catalytic system still shows moderate 3,4-selectivity at 80 °C. Moreover, a facile one-pot synthetic strategy for a polymer blend containing 3,4- and 1,4-polyisoprene (PIP) was established through the in situ modification of the active amidinate yttrium species by addition of an excess amount of AlMe3 .

Reversing Conventional Reactivity of Mixed Oxo/Alkyl Rare-Earth Complexes: Non-Redox Oxygen Atom Transfer.

The preferential substitution of oxo ligands over alkyl ones of rare-earth complexes is commonly considered as "impossible" due to the high oxophilicity of metal centers. Now, it has been shown that simply assembling mixed methyl/oxo rare-earth complexes to a rigid trinuclear cluster framework cannot only enhance the activity of the Ln-oxo bond, but also protect the highly reactive Ln-alkyl bond, thus providing a previously unrecognized opportunity to selectively manipulate the oxo ligand in the presence of numerous reactive functionalities. Such trimetallic cluster has proved to be a suitable platform for developing the unprecedented non-redox rare-earth-mediated oxygen atom transfer from ketones to CS2 and PhNCS. Controlled experiments and computational studies shed light on the driving force for these reactions, emphasizing the importance of the sterical accessibility and multimetallic effect of the cluster framework in promoting reversal of reactivity of rare-earth oxo complexes.

Unprecedented Reaction Mode of Phosphorus in Phosphinidene Rare-Earth Complexes: A Joint Experimental-Theoretical Study.

Reactions of trinuclear rare-earth metal complexes bearing functionalized phosphinidene ligand [L3Ln3(µ2-Me)2(µ3-Me)(µ3-η1:η2:η2-PC6H4-o)] (L = [PhC(NC6H4iPr2-2,6)2]-, Ln = Y (1a), Lu (1b)) with phenylacetylene, CO2, diisopropyl carbodiimide, isocyanide, or PhSSPh lead to the formation of a series of phosphorus-containing products. The reaction of 1 with CS2 yields two novel P-methyl-phosphindole-2,3-dithiolate dianion complexes, revealing an unusual tandem desulfurization/coupling/cyclization reaction mode of CS2. A possible reaction pathway was determined by density functional theory calculations. This emphasizes the key role of the reduction power of the formal P2- part of the phosphinidene in the C-S bond cleavage.

Small molecule activation by mixed methyl/methylidene rare earth metal complexes.

Diverse reactivity patterns of mixed tetramethyl/methylidene rare-earth complexes bearing bulky benzamidinate coligands L3Ln3(µ2-Me)3(µ3-Me)(µ3-CH2) [L = [PhC(NC6H3(i)Pr2-2,6)2](-); Ln = Y(), Lu()] with PhCN, alkynes, and CS2 have been established. Reaction of complexes with PhCN gave the µ3-CH2 addition complexes (NCN(dipp))3Lu3(µ2-Me)3(µ3-Me)[µ-η(1):η(1):η(3)-CH2C(Ph)N] [Ln = Y(), Lu()]. Treatment of complexes with phenylacetylene afforded unexpected alkenyl dianion complexes L3Ln3(µ2-Me)3(µ3-Me)(µ-η(1):η(3)-PhC[double bond, length as m-dash]CMe) [Ln = Y(), Lu()] through the insertion of rare earth methylidene into a C-H bond in a reductive fashion. However, reaction of complexes and HC[triple bond, length as m-dash]CSiMe3 gave µ3-Me protonolysis complexes L3Ln3(µ2-Me)3(µ3-C[triple bond, length as m-dash]CSiMe3)(µ3-CH2) [Ln = Y (), Lu ()] in excellent yields. Treatment of complexes with CS2 led to the formation of the methyl activation complexes L3Ln3(µ2-Me)2(µ3-CH2)(µ3-η(1):η(2):η(2)-S2C[double bond, length as m-dash]CH2) [Ln = Y(), Lu()]. All the new complexes were fully characterized.

Crystal structure of di-µ-iodido-bis-{[1,3-bis-(2,6-diiso-propyl-phen-yl)imidazol-2-yl-idene]lithium}.

In the title binuclear complex, [Li2(C27H36N2)2I2], the unique Li(I) cation is coordinated by two iodide anions and one yl-idene C atom from a 1,3-bis-(2,6-diiso-propyl-phen-yl)imidazol-2-yl-idene ligand in a distorted trigonal-planar geometry. The two symmetry-related iodide anions bridge two Li(I) cations, forming an inversion dimer in which the Li2I2 plane is nearly perpendicular to the imidazol-2-yl-idene ring, with a dihedral angle of 85.5 (3)°. No hydrogen bonding is observed in the crystal.

Homometallic rare-Earth metal phosphinidene clusters: synthesis and reactivity.

Two new trinuclear µ3 -bridged rare-earth metal phosphinidene complexes, [{L(Ln)(µ-Me)}3 (µ3 -Me)(µ3 -PPh)] (L=[PhC(NC6 H4 iPr2 -2,6)2 ](-) , Ln=Y (2 a), Lu (2 b)), were synthesized through methane elimination of the corresponding carbene precursors with phenylphosphine. Heating a toluene solution of 2 at 120 °C leads to an unprecedented ortho CH bond activation of the PhP ligand to form the bridged phosphinidene/phenyl complexes. Reactions of 2 with ketones, thione, or isothiocyanate show clear phospha-Wittig chemistry, giving the corresponding organic phosphinidenation products and oxide (sulfide) complexes. Reaction of 2 with CS2 leads to the formation of novel trinuclear rare-earth metal thione dianion clusters, for which a possible pathway was determined by DFT calculation.

Methylidene rare-earth-metal complex mediated transformations of C=N, N=N and N-H bonds: new routes to imido rare-earth-metal clusters.

Three new patterns of reactivity of rare-earth metal methylidene complexes have been established and thus have resulted in access to a wide variety of imido rare-earth metal complexes [L3Ln3(µ2-Me)3(µ3-Me)(µ-NR)] (L = [PhC(NC6H3iPr2-2,6)2](-); R = Ph, Ln = Y (2 a), Lu (2 b); R = 2,6-Me2C6H3, Ln = Y (3 a), Lu (3 b); R = p-ClC6H4, Ln = Y (4 a), Lu (4 b); R = p-MeOC6H4, Ln = Y (5 a), Lu (5 b); R = Me2CHCH2CH2, Ln = Y (6 a), Lu (6 b)) and [{L3Lu3(µ2-Me)3(µ3-Me)}2(µ-NR'N)] (R' = (CH2)6 (7 b), (C6H4)2 (8 b)). Complex 2 b was treated with an excess of CO2 to give the corresponding carboxylate complex [L3Lu3(µ-η(1):η(1)-O2CCH3)3(µ-η(1):η(2)-O2C-CH3)(µ-η(1):η(1):η(2)-O2CNPh)] (9 b) easily. Complex 2 a could undergo the selective µ3-Me abstraction reaction with phenyl acetylene to give the mixed imido/alkynide complex [L3Y3(µ2-Me)3(µ3-η(1):η(1):η(3)-NPh)(µ3-C≡CPh)] (10 a) in high yield. Treatment of 2 with one equivalent of thiophenol gave the selective µ3-methyl-abstracted products [L3Ln3(µ2-Me)3(µ3-η(1):η(1):η(3)-NPh)(µ3-SPh)] (Ln = Y (11 a); Lu (11 b). All new complexes have been characterized by elemental analysis, NMR spectroscopy, and most of the structures confirmed by X-ray diffraction.

Synthesis, structure and reactivity of dinuclear rare earth metal bis(o-aminobenzyl) complexes bearing a 1,4-phenylenediamidinate co-ligand.

A series of phenylenediamidinate rare earth metal complexes 1,4-C6H4[C(NR)2Ln(o-CH2C6H4NMe2)2]2 (R = 2,6-(i)Pr2-C6H3, Ln = Y (2a), Lu (2b), Sc (2c)) were synthesized by deprotonation of 1,4-C6H4[C(NR)(NHR)]2 (1) with two equivalents of n-BuLi followed by reacting with two equivalents of anhydrous LnCl3 and subsequently four equivalents of Li(o-CH2C6H4NMe2), or by protolysis of [Ln(o-CH2C6H4NMe2)3] with 0.5 equivalent of 1 in THF or toluene. Treatment of complexes 2a and 2b with four equivalents of phenyl isocyanate and phenyl isothiocyanate gave the corresponding insertion products 1,4-C6H4[C(NR)2Ln{OC(CH2C6H4NMe2-o)NPh}2(THF)]2 (Ln = Y (3a), Lu (3b)) and 1,4-C6H4[C(NR)2Ln{SC(CH2C6H4NMe2-o)NPh}2]2 (Ln = Y (4a), Lu (4b)), respectively. The structures of 1, 3b, and 4a were established by X-ray diffraction studies. Complexes 2 show high activity for rac-lactide and ε-caprolactone polymerization; for the former a synergistic effect between two metal centers is observed.

Syntheses, structures, and reactivities of homometallic rare-earth-metal multimethyl methylidene and oxo complexes.

Unsolvated, trinuclear, homometallic, rare-earth-metal multimethyl methylidene complexes [{(NCN)Ln(µ(2)-CH(3))}(3)(µ(3)-CH(3))(µ(3)-CH(2))] (NCN = L = [PhC{NC(6)H(4)(iPr-2,6)(2)}(2)](-); Ln = Sc (2a), Lu (2b)) have been synthesized by treatment of [(L)Ln{CH(2)C(6)H(4)N(CH(3))(2)-o}(2)] (Ln = Sc (1a), Lu (1b)) with two equivalents of AlMe(3) in toluene at ambient temperature in good yields. Treatment of 1 with three equivalents of AlMe(3) gives the heterometallic trinuclear complexes [(L)Ln(AlMe(4))(2)] (Ln = Sc (3a), Lu (3b)) in good yields. Interestingly, 2 can also be generated by recrystallization of 3 in THF/toluene, thereby indicating that the THF molecule can also induce C-H bond activation of 2. Reaction of 2 with one equivalent of ketones affords the trinuclear homometallic oxo-trimethyl complexes [{(L)Ln(µ(2) -CH(3))}(3) (µ(3)-CH(3))(µ(3)-O)] (Ln = Sc(4a), Lu(4b)) in high yields. Complex 4b reacts with one equivalent of cyclohexanone to give the methyl abstraction product [{(L)Lu(µ(2) -CH(3) )}(3) (µ(3) -OC(6)H(9))(µ(3)-O)] (5b), whereas reaction of 4b with acetophenone forms the insertion product [{(L)Lu(µ(2)-CH(3))}(3){µ(3)-OCPh(CH(3))(2)}(µ(3)-O)] (6b). Complex 4a is inert to ketone under the same conditions. All these new complexes have been characterized by elemental analysis, NMR spectroscopy, and confirmed by X-ray diffraction determination.

catena-Poly[[bis-(methanol-κO)bis-(pyridine-κN)nickel(II)]-µ-tetra-fluoro-terephthalato-κO:O'].

In the title compound, [Ni(C(8)F(4)O(4))(C(5)H(5)N)(2)(CH(4)O)(2)](n), the Ni(II) ion is located on an inversion center and is coordinated by four O atoms [Ni-O = 2.079 (4) Å] from two tetra-fluoro-terephthalate ligands and two methanol mol-ecules, and by two N atoms [Ni-N = 2.127 (4) Å] from two pyridine ligands in a distorted octa-hedral geometry. The Ni(II) ions are connected via the tetra-fluoro-terephthalate anions into a one-dimensional chain running along the crystallographic [011] direction.

catena-Poly[[tris-(pyridine-κN)copper(II)]-µ-tetra-fluoro-terephthalato-κO:O].

In the title compound, [Cu(C(8)F(4)O(4))(C(5)H(5)N)(3)](n), the Cu(II) atom, lying on a twofold rotation axis, is five-coordinated by two O atoms from two tetra-fluoro-terephthalate ligands and three N atoms from three pyridine ligands in a distorted trigonal-bipyramidal geometry. Adjacent Cu(II) atoms are connected via the bridging tetra-fluoro-terephthalate ligands into a one-dimensional chain running along the [101] direction.