Cocrystallization and configurations of myo‐inositol‐1,2‐l‐camphor acetals in two crystal structures

The inositol rings in (1S,2R,3R,4S,5S,6R,7S,8S,11S)‐myo‐inositol‐1,2‐camphor acetal {systematic name: (1R,2S,3S,4R,5S,6R)‐5,6‐[(1S,2S,4S)‐1,7,7‐trimethyl­bicyclo­[2.2.1]heptane‐2,2‐diyldi­oxy]cyclohexane‐1,2,3,4‐tetrol}, C₁₆H₂₆O₆, and (1R,2S,3S,4R,5R,6S,7R/S,8S,11S)‐myo‐inositol‐1,2‐camphor acetal trihydrate {systematic name: (1S,2R,3R,4S,5R,6S)‐5,6‐[(1S,4S,6R/S)‐1,7,7‐trimethyl­bicyclo­[2.2.1]heptane‐2,2‐diyldi­oxy]cyclohexane‐1,2,3,4‐tetrol trihydrate}, C₁₆H₂₆O₆·3H₂O, adopt flattened chair conformations with the latter crystal containing two stereoisomers in a 0.684 (2):0.316 (2) ratio, similar to that found both in solution and by calculation. Both mol­ecules pack in the crystals in similar two‐dimensional layers, utilizing strong O—H⋯O hydrogen bonds, with the trihydrate cell expanded to incorporate the additional hydrogen‐bonded water mol­ecules.     

cis‐Di­chloro(5,8‐dioxa‐2,11‐dithia[12]‐o‐cyclo­phane)­palladium(II)

The preparation and crystal structure of the title compound, cis‐di­chloro­[6,9‐dioxa‐3,12‐di­thia­bi­cyclo­[12.4.0]­octadeca‐14,‐16,­18(1)‐tri­ene‐S,S′]­palladium(II), [PdCl₂(C₁₄H₂₀O₂S₂)], are described. The Pd atom has a square‐planar environment, coordinated to two S atoms of the di­thia­dioxa macrocycle and to two Cl^? ions. The non‐coordinating O atoms are oriented away from the metal coordination plane. Upon complexation, a bicyclic chelate structure, which consists of a seven‐ and an eleven‐membered ring, is formed.     

Co‐crystallized cis and trans isomers of dichloro­bis(2‐picolylamine)iron(II)

The octa­hedral cis and trans isomers of dichloro­bis(2‐picolyl­amine)iron(II), [FeCl₂(C₆H₈N₂)₂], co‐crystallize in a 1:1 ratio. The cis isomer lies on a twofold axis, whereas the trans isomer lies on an inversion centre. The structure is fully ordered, with both Fe atoms in a pure high‐spin state. The Fe, Cl and N(H₂) atoms of both isomers lie in the same plane, allowing all Cl and amine H atoms to be engaged in extensive two‐dimensional hydrogen bonding. The hydrogen‐bonded layers are inter­connected through π–π inter­actions between the pyridine rings. Searches in the Cambridge Structural Database uncover very few examples of such isomer co‐existence.     

cis‐[1,4‐Bis(di­phenyl­phosphino)­butane](μ‐tetra­thio­tungstato)­palladium(II) N,N′‐di­methyl­form­amide hemisolvate hemihydrate

In the title compound, [1,4‐bis(di­phenyl­phosphino)­butane‐2κ²P,P′]­di‐μ‐thio‐1:2κ⁴S‐di­thio‐1κ²S‐palladium(II)­tung­sten(VI) N,N′‐di­methyl­form­amide hemisolvate hemihydrate, [PdWS₄­(C₂₈H₂₈P₂)]·0.5C₃H₇NO·0.5H₂O, the Pd atom is coordinated by two S atoms from the distorted‐tetrahedral [WS₄]²⁻ anion and two P atoms from the dppb mol­ecule [dppb is 1,4‐bis(di­phenyl­phos­phino)­butane] in an approximately square‐planar configuration. A puckered seven‐membered ring is formed by the Pd atom and the dppb ligand.     

Dichloro­[(6R,7S,8S,14S)‐(–)‐sparteine‐κ2N,N′]mercury(II)

In the title compound, [HgCl₂(C₁₅H₂₆N₂)], the chiral alkaloid (6R,7S,8S,14S)‐(−)‐l ‐sparteine acts as a bident­ate ligand, with two Cl⁻ ligands occupying the remaining coordination sites, producing a distorted tetra­hedron. The N—Hg—N plane is twisted by 81.1 (2)° from the Cl—Hg—Cl plane. The mid‐point of the N⋯N line does not lie exactly on the Cl—Hg—Cl plane but is tilted towards one of the N atoms by 0.346 Å. Similarly, the mid‐point of the Cl⋯Cl line is tilted toward one of the Cl atoms by 0.163 Å. The packing structure shows that the complex is stabilized by two inter­atomic Cl⋯H contacts involving both Cl atoms and the methyl­ene or methine H atoms of the (−)‐sparteine ligand.     

New electron‐deficient chiral phosphines: (4R,5R)‐1,3‐bis(trifluoromethanesulfonyl)perhydro‐1,3,2‐benzodiazaphosphol‐2‐yl] substituted amines

Three chiral electron‐deficient phosphine ligands, [(4R,15R)‐,3‐bis­(tri­fluoro­methane­sulfonyl)­per­hydro‐1,3,2‐benzodiazaphosphol‐2‐yl]­diethyl­amine, C₁₂H₂₀F₆N₃O₄PS₂, (IIIa), [(4R,5R)‐1,3‐bis­(tri­fluoro­methane­sulfonyl)­per­hydro‐1,3,2‐benzodi­aza­phosphol‐2‐yl]­di­methyl­amine, C₁₀H₁₆F₆N₃O₄PS₂, (IIIb), and bis­[(4R,5R)‐1,3‐bis­(tri­fluoro­methane­sulfonyl)­per­hydro‐1,3,2‐benzodi­aza­phosphol‐2‐yl]­methyl­amine, (IV), as the chloroform solvate, C₁₇H₂₃F₁₂N₅O₈P₂S₄·0.98CHCl₃, have been prepared from (1R,2R)‐N,N′‐bis­(tri­fluoro­methane­sulfonyl)‐1,2‐cyclo­hexane­di­amine and diethyl phosphor­amido­us dichloride, dimethyl phosphoramidous dichloride or methyl imidodi­phosphorus tetrachloride. The π‐acceptor abilities of these new types of ligands have been evaluated by X‐ray determination of the P—N bond lengths; it has been found that the most promising ligand is the bis­(phosphine) (IV).     

The diastereoisomers methyl 5‐(S)‐[2‐(R)/(S)‐methoxycarbonyl)‐2,3,4,5‐tetrahydropyrrol‐1‐ylcarbonyl]‐1‐(4‐methylphenyl)‐4,5‐dihydropyrazole‐3‐carboxylate

The title diastereoisomers, methyl 5‐(S)‐[2‐(S)‐methoxy­carbonyl)‐2,3,4,5‐tetra­hydro­pyrrol‐1‐yl­carbonyl]‐1‐(4‐methyl­phenyl)‐4,5‐di­hydro­pyrazole‐3‐carboxyl­ate and methyl 5‐(S)‐[2‐(R)‐methoxycarbonyl)‐2,3,4,5‐tetrahydropyrrol‐1‐ylcarbonyl]‐1‐(4‐methyl­phenyl)‐4,5‐di­hydro­pyrazole‐3‐carboxylate, both C₁₉H₂₃N₃O₅, have been studied in two crystalline forms. The first form, methyl 5‐(S)‐[2‐(S)‐methoxy­carbonyl)‐2,3,4,5‐tetrahydropyrrol‐1‐ylcarbonyl]‐1‐(4‐methylphenyl)‐4,5‐di­hydro­pyrazole‐3‐carboxyl­ate–methyl 5‐(S)‐[2‐(R)‐methoxy­carbonyl)‐2,3,4,5‐tetra­hydro­pyrrol‐1‐yl­carbonyl]‐1‐(4‐methylphenyl)‐4,5‐dihydropyrazole‐3‐carboxylate (1/1), 2(S),5(S)‐C₁₉H₂₃N₃O₅·2(R),5(S)‐C₁₉H₂₃N₃O₅, contains both S,S and S,R isomers, while the second, methyl 5‐(S)‐[2‐(S)‐methoxycarbonyl)‐2,3,4,5‐tetrahydro­pyrrol‐1‐ylcarbonyl]‐1‐(4‐methyl­phenyl)‐4,5‐di­hydro­pyrazole‐3‐carboxyl­ate, 2(S),5(S)‐C₁₉H₂₃N₃O₅, is the pure S,S isomer. The S,S isomers in the two structures show very similar geometries, the maximum difference being about 15° on one torsion angle. The differences between the S,S and S,R isomers, apart from those due to the inversion of one chiral centre, are more remarkable, and are partially due to a possible rotational disorder of the 2‐­(methoxycarbonyl)tetrahydropyrrole group.     

An intermediate in a new synthesis approach to β‐substituted β‐hydroxy­aspartame

The crystal and molecular structure of 1‐tert‐butyl 4‐ethyl (2′R,3′R,5′R,2S,3S)‐3‐bromo­methyl‐3‐hydroxy‐2‐[(2′‐hydroxy‐2′,6′,6′‐tri­methyl­bi­cyclo­[3.1.1]­hept‐3′‐yl­idene)­amino]­succinate, C₂₁H₃₄BrNO₆, is presented. This compound is an intermediate in the new synthetic route to β‐substituted β‐hydroxy­aspartates, which are blockers of glutamate transport.     

Tetrakis(dimethyl sulfide)palladium(II) bis(tetrafluoroborate) and tetrakis(1,4‐oxathiane‐κS)palladium(II) bis(tetrafluoroborate)

Tetrakis(dimethyl sulfide)palladium(II) bis(tetrafluoroborate), [Pd(C₂H₆S)₄](BF₄)₂, (I), and tetrakis(1,4‐oxa­thiane‐κS)palladium(II) bis­(tetra­fluoro­borate), [Pd(C₄H₈OS)₄](BF₄)₂, (II), both crystallize as mononuclear square‐planar complexes with tetra­fluoro­borate as the counter‐ions. The Pd atom accepts four S‐donor atoms and is positioned at an inversion centre in both compounds. The two unique S atoms in the di­methyl sulfide complex, (I), are disordered. The Pd—S distances are in the range 2.3338 (12)–2.3375 (12) Å in (I), and the corresponding distances in the thio­xane complex, (II), are 2.3293 (17) and 2.3406 (17) Å. The anions in both compounds interact weakly with the Pd atom.     

Poly[[μ‐aqua‐bis­(μ‐2,4‐dichloro­phen­oxy­acetato)barium(II)] monohydrate]

In the title coordination polymer, {[Ba(C₈H₅Cl₂O₃)₂(H₂O)]·H₂O}_n, each Ba^II atom is nine‐coordinated by six carboxyl­ate O atoms and one ether O atom from five symmetry‐related 2,4‐dichloro­phenoxy­acetate ligands, and by two O atoms from water mol­ecules, thus defining a distorted tricapped trigonal prism. The Ba^II ions are bridged by bidentate water mol­ecules and by tridentate and tetra­dentate 2,4‐dichloro­phenoxy­acetate groups, leading to a two‐dimensional layer structure. The crystal structure is further stabilized by hydrogen‐bonding inter­actions within each layer.     

New palladium complexes with phosphino‐ and phosphinitopyridine ligands

Three new palladium complexes containing a difunctional P,N‐chelate, namely tris­(chloro­{[1‐methyl‐1‐(6‐methyl‐2‐pyridyl)ethoxy]diphenylphospine‐κ²N,P}methyl­palladium(II)chloro­form solvate, 3[Pd(CH₃)Cl(C₂₁H₂₂NOP)]·CHCl₃, (III), dichloro­[2‐(2,6‐dimethyl­phen­yl)‐6‐(diphenyl­phosphinometh­yl)­pyridine‐κ²N,P]palladium(II), [PdCl₂(C₂₆H₂₄NP)], (IV), and chloro­[2‐(2,6‐dimethyl­phen­yl)‐6‐(diphenyl­phos­phino­meth­yl)pyridine‐κ²N,P]methyl­palladium(II), [Pd(CH₃)Cl(C₂₆H₂₄NP)], (V), are reported. Geometric data and the conformations of the ligands around the metal centers, as well as slight distortions of the Pd coordination environments from idealized square‐planar geometry, are discussed and compared with the situations in related compounds. Non‐conventional hydrogen‐bond inter­actions (C—H⋯Cl) have been found in all three complexes. Compound (III) is the first six‐membered chloro–meth­yl–phosphinite P,N‐type Pd^II complex to be structurally characterized.     

Resolution of (S,S)‐4‐(2,2,4‐tri­methyl­chroman‐4‐yl)­phenyl camphanate and its 4‐chromanyl epimer by crystallization

Dianin's compound (4‐p‐hydroxy­phenyl‐2,2,4‐tri­methyl­chroman) has been resolved by crystallization of the (S)‐(−)‐camphanic esters (S,S)‐ and (R,S)‐4‐(2,2,4‐tri­methyl­chroman‐4‐yl)­phenyl 4,7,7‐tri­methyl‐3‐oxo‐2‐oxabi­cyclo[2.2.1]heptane‐1‐carboxyl­ate, both C₂₈H₃₂O₅, from 2‐methoxy­ethanol, yielding the pure S,S diastereomer. The relative stereochemistry of both diastereomers has been determined by X‐ray crystallography, from which the absolute stereochemistry could be deduced from the known configuration of the camphanate moiety. The crystallographic conformations have been analysed, including the 1:1 disorder of the R,S diastereomer.     

Bis­[(R)‐3,5‐di­chloro‐N‐(1‐phenyl­ethyl)­salicyl­idene­aminato‐κ2N,O]­copper(II) and bis­[(R)‐3‐ethoxy‐N‐(1‐phenyl­ethyl)­salicyl­idene­aminato‐κ2N,O]copper(II)

The title compounds, [Cu(C₁₅H₁₂Cl₂NO)₂], (I), and [Cu(C₁₇­H₁₈NO₂)₂], (II), both adopt a compressed tetrahedral trans‐[CuN₂O₂] coordination geometry, the mol­ecules having an umbrella conformation overall. These complexes differ from one another with respect to the 1‐phenyl­ethyl­amine moieties, the direction of the benzene rings being either inside [in (I)] or inside and outside [in (II)] of the mol­ecules. The crystals of (I) and (II) have Δ(R,R) and Λ(R,R) absolute configurations, respectively.     

[5‐Benzyl‐3‐phenyl‐2‐(2‐pyridyl‐κN)thiazolidin‐4‐one‐κS]dichloropalladium(II)

The palladium(II) centre in the title compound, [PdCl₂(C₂₁H₁₈N₂OS)], is coordinated to the pyridyl N atom and to the thia­zolidinone S atom of the 5‐benzyl‐3‐phenyl‐2‐(2‐pyridyl)­thia­zolidin‐4‐one ligand, resulting in a five‐membered chelate ring. Two cis‐chloro ligands complete the square‐planar coordination environment of the metal. Although the geometry at the Pd centre is essentially planar, the N—Pd—S bite angle of 85.20 (8)° causes deviations in the cis angles from the ideal value of 90°. Opposite enantiomers form one‐dimensional chains in the cell via a short S?O intermolecular interaction.     

(1R,2R)‐2‐(4‐Methylenecyclohex‐2‐enyl)propyl (1R,4S)‐camphanate

Esterification of a single diastereomer of 2‐(4‐methylene­cyclohex‐2‐enyl)propanol, (II), with (1R,4S)‐(+)‐camphanic acid [(1R,4S)‐4,7,7‐trimethyl‐3‐oxo‐2‐oxabicyclo[2.2.1]heptane‐1‐carboxylic acid] leads to the crystalline title compound, C₂₀H₂₈O₄. The relative configuration of the camphanate was determined by X‐ray diffraction analysis. The outcome clarifies the relative and absolute stereochemistry of the naturally occurring bisabolane sesquiterpenes β‐turmerone and β‐sesquiphellandrene, since we have converted (II) into both natural products via a stereospecific route.     

A new optically pure half‐sandwich Cp–Ru diphosphine complex with a chiral metal centre, (S)‐Ru(η5‐C5H5)(EPHOS)Cl {EPHOS is (+)‐(1R,2S)‐2‐[(diphenylphosphino)methylamino]‐1‐phenylpropyl diphenylphosphinite}

The crystal structure of the title compound, chloro(η⁵‐cyclopenta­dienyl){(1R,2S)‐2‐[(di­phenyl­phosphino)­methyl­amino]‐1‐phenyl­propyl di­phenyl­phosphinite‐κ²P,P′}ruthenium(II), [Ru(C₅H₅)Cl(C₃₄H₃₃NOP₂)], is reported. The pseudo‐octa­hedral complex is chiral and the configuration at the Ru atom is S. The seven‐membered metallacycle adopts a boat‐like conformation.     

The absolute configuration of (2S,4S)‐ and (2R,4R)‐2‐tert‐butyl‐4‐methyl‐3‐(4‐tolyl­sulfon­yl)‐1,3‐oxazolidine‐4‐carbaldehyde

The title enanti­omorphic compounds, C₁₆H₂₃NO₄S, have been obtained in an enanti­omerically pure form by crystallization from a diastereomeric mixture either of (2S,4S)‐ and (2R,4S)‐ or of (2R,4R)‐ and (2S,4R)‐2‐tert‐butyl‐4‐methyl‐3‐(4‐tolyl­sulfon­yl)‐1,3‐oxazolidine‐4‐carbaldehyde. These mixtures were prepared by an aziridination rearrangement process starting with (S)‐ or (R)‐2‐tert‐butyl‐5‐methyl‐4H‐1,3‐dioxine. The crystal structures indicate an envelope conformation of the oxazolidine moiety for both compounds.     

cis‐Dichlorido(3,6,9‐trithiabicyclo[9.3.1]pentadecane‐κ2S3,S6)palladium(II) acetonitrile 0.8‐solvate

In the title complex, [PdCl₂(C₁₂H₂₂S₃)]·0.8CH₃CN, a potentially tridentate thioether ligand coordinates in a cis‐bidentate manner to yield a square‐planar environment for the Pd^II cation [mean deviation of the Pd from the Cl₂S₂ plane = 0.0406 (7) Å]. Each square‐planar entity packs in an inverse face‐to‐face manner, giving pairs with plane‐to‐plane separations of 3.6225 (12) Å off‐set by 1.1263 (19) Å, with a Pd...Pd separation of 3.8551 (8) Å. A partial acetonitrile solvent molecule is present. The occupancy of this molecule was allowed to refine, and converged to 0.794 (10). The synthesis of the previously unreported 3,6,9‐trithiabicyclo[9.3.1]pentadecane ligand is also outlined.     

Asymmetric Syntheses of New Polyhydroxylated Quinolizidines: Cross‐Aldol Reactions of 7‐Oxabicyclo[2.2.1]heptan‐2‐one and 3a,4a,7a,7b‐Tetrahydro[1,3]dioxolo[4,5]furo[2,3‐d]isoxazole‐3‐carbaldehyde Derivatives

The cross‐aldolization of (−)‐(1S,4R,5R,6R)‐6‐endo‐chloro‐5‐exo‐(phenylseleno)‐7‐oxabicyclo[2.2.1]heptan‐2‐one ((−)‐ 25 ) and of (+)‐(3aR,4aR,7aR,7bS)‐ ((+)‐ 26 ) and (−)‐(3aS,4aS,7aS,7bR)‐3a,4a,7a,7b‐tetrahydro‐6,6‐dimethyl[1,3]dioxolo[4,5]furo[2,3‐d]isoxazole‐3‐carbaldehyde ((−)‐ 26 ) was studied for the lithium enolate of (−)‐ 25 and for its trimethylsilyl ether (−)‐ 31 under Mukaiyama's conditions (Scheme 2). Protocols were found for highly diastereoselective condensation giving the four possible aldols (+)‐ 27 (`anti'), (+)‐ 28 (`syn'), 29 (`anti'), and (−)‐ 30 (`syn') resulting from the exclusive exo‐face reaction of the bicyclic lithium enolate of (−)‐ 25 and bicyclic silyl ether (−)‐ 31 . Steric factors can explain the selectivities observed. Aldols (+)‐ 27 , (+)‐ 28 , 29 , and (−)‐ 30 were converted stereoselectively to (+)‐1,4‐anhydro‐3‐{(S)‐[(tert‐butyl)dimethylsilyloxy][(3aR,4aR,7aR,7bS)‐3a,4a,7a,7b‐tetrahydro‐6,6‐dimethyl[1,3]dioxolo[4,5]‐furo[2,3‐d]isoxazol‐3‐yl]methyl}‐3‐deoxy‐2,6‐di‐O‐(methoxymethyl)‐α‐D ‐galactopyranose ((+)‐ 62 ), its epimer at the exocyclic position (+)‐ 70 , (−)‐1,4‐anhydro‐3‐{(S)‐[(tert‐butyl)dimethylsilyloxy][(3aS,4aS,7aS,7bR)‐3a,4a,7a,7b‐tetrahydro‐6,6‐dimethyl[1,3]dioxolo[4,5]furo[2,3‐d]isoxazol‐3‐yl]methyl}‐3‐deoxy‐2,6‐di‐O‐(methoxymethyl)‐α‐D ‐galactopyranose ((−)‐ 77 ), and its epimer at the exocyclic position (+)‐ 84 , respectively (Schemes 3 and 5). Compounds (+)‐ 62 , (−)‐ 77 , and (+)‐ 84 were transformed to (1R,2R,3S,7R,8S,9S,9aS)‐1,3,4,6,7,8,9,9a‐octahydro‐8‐[(1R,2R)‐1,2,3‐trihydroxypropyl]‐2H‐quinolizine‐1,2,3,7,9‐pentol ( 21 ), its (1S,2S,3R,7R,8S,9S,9aR) stereoisomer (−)‐ 22 , and to its (1S,2S,3R,7R,8S,9R,9aR) stereoisomer (+)‐ 23 , respectively (Schemes 6 and 7). The polyhydroxylated quinolizidines (−)‐ 22 and (+)‐ 23 adopt `trans‐azadecalin' structures with chair/chair conformations in which H−C(9a) occupies an axial position anti‐periplanar to the amine lone electron pair. Quinolizidines 21 , (−)‐ 22 , and (+)‐ 23 were tested for their inhibitory activities toward 25 commercially available glycohydrolases. Compound 21 is a weak inhibitor of β‐galactosidase from jack bean, of amyloglucosidase from Aspergillus niger, and of β‐glucosidase from Caldocellum saccharolyticum. Stereoisomers (−)‐ 22 and (+)‐ 23 are weak but more selective inhibitors of β‐galactosidase from jack bean.     

trans‐[1,3‐Bis(2,4‐di­methyl­phenyl)­imidazolidin‐2‐yl­idene]­di­chloro­(tri­phenyl­phosphine‐κP)­palladium(II)

The title complex, [PdCl₂(C₁₉H₂₂N₂)(C₁₈H₁₅P)], shows slightly distorted square‐planar coordination of the palladium(II) metal center. The Pd—C bond distance between the N‐heterocyclic ligand and the metal atom is 2.008 (3) Å. The dihedral angle between the two di­methyl­phenyl ring planes is 33.17 (13)°.