Trapped Intermediate of a Meerwein-Pondorf-Verley Reduction of Hydroxy Benzaldehyde to a Dialkoxide by Titanium Alkoxides.

A series of titanium alkoxides ([Ti(OR)] (OR = OCH(CH) (OPr), OC(CH) (OBu), and OCHC(CH) (ONep)) were modified with a set of substituted hydroxyl-benzaldehydes [HO-BzA-L: = 1, 2-hydroxybenzaldehyde (L = H), 2-hydroxy-3-methoxybenzaldehyde (OMe-3), 5-bromo-2-hydroxybenzaldehyde (Br-5), 2-hydroxy-5-nitrobenzaldehyde (NO-5); = 2, 3,5-di--butyl-2-hydroxybenzaldehyde (Bu-3,5), 2-hydroxy-3,5-diiodobenzaldehyde (I-3,5)] in pyridine (py). Instead of the expected simple substitution, each of the HO-BzA-L modifiers were reduced to their respective diol [(py)(OR)Ti(κ(O,μ-O')(OCH(CHO)-2)(L)] (OR = OPr, = 1, L = H (), OMe-3 (), Br-5 (·py), NO-5 (·4py); = 2, Bu-3,5 (), I-3,5 (), ONep; = 1, L = H (), OMe-3 (), Br-5 (·py), NO-5 (); = 2, Bu-3,5 (), I-3,5 (·py)), as identified by single crystal X-ray studies. The H NMR spectral data were complex at room temperature but simplified at high temperatures (70 °C).

Synthesis, Characterization, and Nanomaterials Generated from 6,6'-(((2-Hydroxyethyl)azanediyl)bis(methylene))bis(2,4-di- tert-butylphenol) Modified Group 4 Metal Alkoxides.

The impact on the morphology nanoceramic materials generated from group 4 metal alkoxides ([M(OR)]) and the same precursors modified by 6,6'-(((2-hydroxyethyl)azanediyl)bis(methylene))bis(2,4-di- tert-butylphenol) (referred to as H-AM-DBP (1)) was explored. The products isolated from the 1:1 stoichiometric reaction of a series of [M(OR)] where M = Ti, Zr, or Hf; OR = OCH(CH)(OPr ); OC(CH)(OBu ); OCHC(CH)(ONep) with H-AM-DBP proved, by single crystal X-ray diffraction, to be [(ONep)Ti( k( O,O',O'',N)-AM-DBP)] (2), [(OR)M(μ( O)- k( O',O'',N)-AM-DBP)] [M = Zr: OR = OPr , 3·tol; OBu , 4·tol; ONep, 5·tol; M = Hf: OR = OBu , 6·tol; ONep, 7·tol]. The product from each system led to a tetradentate AM-DBP ligand and retention of a parent alkoxide ligand.

Synthesis and Characterization of Tris(trimethylsilyl)siloxide Derivatives of Early Transition Metal Alkoxides That Thermally Convert to Varied Ceramic-Silica Architecture Materials.

In an effort to generate single-source precursors for the production of metal-siloxide (MSiO ) materials, the tris(trimethylsilyl)silanol (H-SST or H-OSi(SiMe) (1) ligand was reacted with a series of group 4 and 5 metal alkoxides. The group 4 products were crystallographically characterized as [Ti(SST)(OR)] (OR = OPr (2), OBu (3), ONep (4)); [Ti(SST)(OBu )] (5); [Zr(SST)(OBu )(py)] (6); [Zr(SST)(OR)] (OR = OBu (7), ONep, (8)); [Hf(SST)(OBu )] (9); and [Hf(SST)(ONep)(py) ] ( n = 1 (10), n = 2 (10a)) where OPr = OCH(CH), OBu = OC(CH), OBu = O(CH)CH, ONep = OCHC(CH), py = pyridine. The crystal structures revealed varied SST substitutions for: monomeric Ti species that adopted a tetrahedral ( T-4) geometry; monomeric Zr compounds with coordination that varied from T-4 to trigonal bipyramidal ( TBPY-5); and monomeric Hf complexes isolated in a TBPY-5 geometry.

Ni-Catalyzed Regioselective β,δ-Diarylation of Unactivated Olefins in Ketimines via Ligand-Enabled Contraction of Transient Nickellacycles: Rapid Access to Remotely Diarylated Ketones.

We disclose a [(PhO)P]/NiBr-catalyzed regioselective β,δ-diarylation of unactivated olefins in ketimines with aryl halides and arylzinc reagents. This diarylation proceeds at remote locations to the carbonyl group to afford, after simple H workup, diversely substituted β,δ-diarylketones that are otherwise difficult to access readily with existing methods. Deuterium-labeling and crossover experiments indicate that diarylation proceeds by ligand-enabled contraction of transient nickellacycles.

Synthesis and characterization of thallium-salen derivatives for use as underground fluid flow tracers.

A pair of thallium salen derivatives was synthesized and characterized for potential use as monitors (or taggants) or as models for Group 13 complexes for subterranean fluid flows. These precursors were isolated from the reaction of thallium ethoxide with N,N'-bis(3,5-di-tert-butylsalicylidene)-ethylenediamine (H-salo-Bu), or N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-phenylenediamine (H-saloPh-Bu). The products were identified by single crystal X-ray diffraction as: [((μ-O),κ-(N)(N')salo-Bu)Tl] (1) and {[((μ-O)saloPh-Bu)Tl][((μ-O),κ-(N)(N')saloPh-Bu)Tl]} (2).

Synthesis and Characterization of Structurally Diverse Alkaline-Earth Salen Compounds for Subterranean Fluid Flow Tracking.

A family of magnesium and calcium salen-derivatives was synthesized and characterized for use as subterranean fluid flow monitors. For the Mg complexes, di- n-butyl magnesium ([Mg(Bu )]) was reacted with N, N'-ethylene bis(salicylideneimine) (H-salen), N, N'-bis(salicylidene)-1,2-phenylenediamine (H-saloPh), N, N'-bis(3,5-di- t-butylsalicylidene)-ethylenediamine (H-salo-Bu ), or N, N'-bis(3,5-di- t-butylsalicylidene)-1,2-phenylenediamine (H-saloPh-Bu ), and the products were identified by single-crystal X-ray diffraction as [(κ-(O,N,N'),μ-(O')saloPh)(μ-(O),(κ-(N,N'),μ-(O')saloPh)(μ-(O),κ-(N,N',O')saloPh')Mg]·2tol (1·2tol; saloPh' = an alkyl-modified saloPh derivative generated in situ), [(κ-(O,N,N',O')saloPh)Mg(py)]·py (2·py), [(κ-(O,N,N',O')salo-Bu )Mg(py)] (3), [(κ-(O,N,N',O')saloPh-Bu )Mg(py)]·tol (4·tol), and [(κ-(O,N,N'),μ-(O')saloPh-Bu )Mg] (5), where tol = toluene; py = pyridine. For the Ca species, a calcium amide was independently reacted with H-salo-Bu and H-saloPh-Bu to generate the crystallographcially characterized compounds: [(κ-(O,N,N',O')salo-Bu )Ca(py)] (6), [(κ-(O,N,N',O')saloPh-Bu )Ca(py)]·py (7·py).

Ni-Catalyzed Regioselective 1,2-Dicarbofunctionalization of Olefins by Intercepting Heck Intermediates as Imine-Stabilized Transient Metallacycles.

We disclose a strategy for Ni-catalyzed dicarbofunctionalization of olefins in styrenes by intercepting Heck C(sp)-NiX intermediates with arylzinc reagents. This approach utilizes a readily removable imine as a coordinating group that plays a dual role of intercepting oxidative addition species derived from aryl halides and triflates to promote Heck carbometalation and stabilizing the Heck C(sp)-NiX intermediates as transient metallacycles to suppress β-hydride elimination and facilitate transmetalation/reductive elimination steps. This method affords diversely substituted 1,1,2-triarylethyl products that occur as structural motifs in various natural products.

Structural Properties of the Acidification Products of Scandium Hydroxy Chloride Hydrate.

The structural properties of a series of scandium inorganic acid derivatives were determined. The reaction of Sc(0) with concentrated aqueous hydrochloric acid led to the isolation of [(H2O)5Sc(μ-OH)]24Cl·2H2O (1). Compound 1 was modified with a series of inorganic acids (i.

Hemilabile β-aminophosphine ligands derived from 1,3,5-triaza-7-phosphaadamantane: application in aqueous ruthenium catalyzed nitrile hydration.

A series of β-aminophosphines derived from 1,3,5-triaza-7-phosphaadamantane (PTA) are described. PTA-CHPhNHPh (1), PTA-CH(p-C(6)H(4)OCH(3))NHPh (2), and PTA-CPh(2)NHPh (3) were prepared in good yield (62-77%) by reaction of lithiated PTA with the corresponding imine followed by hydrolysis. Compounds 1 and 2 were synthesized as pairs of diastereomers which were separated by successive recrystallization from THF/hexane.