Selective transannular ring transformations in azirino-fused eight-membered O,N- or S,N-heterocycles

The first examples of transannular ring transformations in azirino-fused eight-membered O,N- or S,N-heterocycles involving selective aziridine ring opening and medium-sized ring contraction are described, which provide an access to functionalized 1,4-benzox(thi)azines or 1,3-benzox(thi)azoles.     

Synthesis and Characterization of N-(O,O-Dialkyl Phosphoryl)-D-glucosamine

Using D-glucosamine hydrochloride as a starting material and alkylphosphite as the phosphorylating agent, a new analogue of glycosyl phosphate, namely N-(O, O-dialkyl phosphoryl)-D-glucosamine, was synthesized without hydroxyl protection by Atherton–Todd reaction. The structure of N-(O, O-dialkyl phosphoryl)-D-glucosamine was determined by FT-IR, ¹H NMR, ¹³C NMR, ³¹P NMR, and HR MS. This concise and convenient synthetic pathway provides a new approach for the preparation of N-phosphoryl glucosamine derivatives.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

含O-, S-, N-和C-2,3-不饱和糖苷的合成

以3,4,6-三-O-乙酰基-D-葡萄烯糖为原料,(NH₄)₂S₂O₈为催化剂,利用Ferrier重排反应制得一系列含O-, S-,N-和C-2,3-不饱和糖苷,其结构经¹H NMR, IR和MS（ESI）确证。考察了催化剂及其用量,溶剂和温度对产率的影响。结果表明：在最优条件［反应温度80 ℃,乙腈为溶剂,(NH₄)₂S₂O₈为催化剂(1 eq.)］下,3a产率高达83%。     

Chiral Discrimination in N-(O, O-dialkyl)phosphoamino Acid Monolayers at the Air-water Interface

The chirality of phospholipids is known to be of importance to the interactions of the cellmembrane with proteins and other substances passing through it. Langmuir monolayersat the air/water interface provide unique models for stUdying chirality-dependentintermolecular interactions in highly organized tWo-dimensional systems'-'. Our recentwork confirmed that long chain N - (O, O - d ialkyl)pho sphoam in o ac ids c cul d form b if ayermembrane vesicles in water4. This suggests that perhaps th…     

ESI／MS of N-（O, O-Diisopropyl） Phosphoryl Aromatic Amino Acids and their Stability Investigation Using HPLC／UV／ESI／MS

The full scan ESI/MS and ESI/MS^2 of N-(O, O-diisopropyl) phosphoryl aromatic amino acids (DIPPAAAs), N-(O, O-diisopropyl) phosphoryl phenylalanine, N-(O, O-diisopropyl)phosphoryl tryptophan and N-(O, O-diisopropyl) phosphoryl tyrosine, were obtained. The specific ions for them were found. Their stability in the LC mobile phase was investigated using developed HPLC/UV/ESI/MS and the results demonstrated that the DIPPAAAs were stable in the mobile phase (5 mmol/L NH4Ac-MeCN (80:20,v/v, pH7.5) within 48 h.     

Synthesis and characterization of rhenium(V) oxo complexes with N-[N-(3-diphenylphosphinopropionyl)glycyl]cysteine methyl ester. X-ray crystal structure of (ReO[Ph(2)P(CH(2))(2)C(O)-Gly-Cys-OMe(P,N,N,S)])

The PN(2)S chelate N-[N-(3-diphenylphosphinopropionyl)glycyl]-S-tritylcysteine methyl ester [PN(2)S(Trt)-OMe] was synthesized and reacted with ReOCl(3)(PPh(3))(2) and Ph(4)P[ReOCl(4)]. The reactions of both tritylated and detritylated ligands with Re(V)O precursors gave two diastereomers, 9a and 9b, of the ReO(PN(2)S-OMe) complex. The two isomers, produced in a 1:1 molar ratio, are stable and do not interconvert. They were separated by reverse-phase HPLC and characterized by NMR, FT-IR, and UV-visible spectroscopy and electrospray mass spectrometry. X-ray analysis established for 9a the presence in the solid of the syn isomer. Compound 9a, C(21)H(23)N(2)O(5)PSRe, crystallized from warm acetonitrile in the triclinic space group Ponemacr;, a = 9.828(2) A, b = 11.163(2) A, c = 11.641(2) A, alpha = 106.48(3) degrees, beta = 109.06(3) degrees, gamma = 102.81(3) degrees, V = 1085.7(4) A(3), Z = 2. The PN(2)S coordination set is in the equatorial plane, and the complex shows a distorted square pyramidal coordination. The anti configuration assigned to 9b is consistent with all the available physicochemical data. Follow-up of the reaction of the detritylated ligand with Ph(4)P[ReOCl(4)] in ethanol or acetonitrile indicated that the phosphorus atom of the chelate binds first to the metal and that this bond acts as the driving force for coordination.     

Zinkkomplexe des chelatisierenden N,S,S-Liganden N-(2-Mercaptoethyl)-2-mercaptoanilin

Zinc Complexes of the Chelating N,S,S Ligand N-(2-Mercaptoethyl)-2-mercaptoaniline The organic compound N-(2-mercaptoethyl)-2-mercaptoaniline (LH₂) which as a ligand offers two SH functions, which can be deprotonated, and one NH donor function was prepared by a new method. Its reaction with zinc salts yielded the 1:1 complex ZnL. The structure analysis identified the complex as a molecular tetramer with bridging thiolate groups, a tetrahedral ZnNS₃ coordination, and a step-like Zn₄S₄ ring as the central structural unit. Attempts to break up the tetramer by addition of coligands were successful only for 2,2′-bipyridine which produced the complex LZn · bipy.     

Synthesis, characterization, and hydrolytic behavior of mixed-ligand diorganotin esters, [R2Sn(O2CR')OSO2Me]2 (R=n-Pr, n-Bu; R'=C9H6N-2, 4-OMe-C9H5N-2, C9H6N-1)

Reactions of the tin precursors, R2Sn(OMe)OSO2Me (R=n-Pr, n-Bu), with an equimolar quantity of 2-quinoline/4-methoxy-2-quinoline/1-isoquinoline carboxylic acid in acetonitrile proceed under mild conditions (rt,12-15 h) via selective Sn-OMe bond cleavage to afford the corresponding mixed-ligand diorganotin derivatives [R2Sn(O2CR')OSO2Me]2 [R'=C9H6N-2, R=n-Pr (1), n-Bu (2); R'=4-OMe-C9H5N-2, R=n-Pr (3), n-Bu (4); R'=C9H6N-1, R=n-Pr (5), n-Bu (6)]. These have been characterized by FAB mass, IR, and multinuclear (1H, 13C, 119Sn) NMR spectral data and X-ray crystallography (for 4 and 6). The molecular structure of 4 (C20H29NO6SSn, monoclinic, P2(1)/n, a=14.1(13) A, b=16.7(18) A, c=20.3(19) A, beta=107(4) degrees, Z=8) comprises distorted octahedral geometry around each tin atom by virtue of weakly bridging methanesulfonate [Sn(1A)-O(3B)=3.010, Sn(1B)-O(3A)=2.984 A] and (N,O) chelation of the carboxylate ligands. The spectral data of 1-4 suggest a similar structural motif in solution. The molecular structure of 6 (C38H53N2O10S2Sn2, monoclinic, P2(1)/c, a=11.339(2) A, b=14.806(3) A, c=24.929(5) A, beta=100.537(3) degrees, Z=4) reveals varying bonding preferences with monomeric units being held together by a bridging methanesulfonate [Sn(2)-O(5)=2.312(2) A] and a carboxylate group bonded to Sn(1) and Sn(2) atoms, respectively. Slow hydrolysis of compound 2 derived from 2-quinoline carboxylic acid in moist CH3CN affords the asymmetric distannoxane, [Bu2Sn(O2CC9H6N-2)-O-Sn(OSO2Me)Bu2]2 (7) (C27H45NO6SSn2, monoclinic, C2/c, a=21.152(3) A, b=13.307(2) A, c=26.060(4) A, beta=110.02(10) degrees, Z=8) featuring ladder type structural motif by virtue of unique mu2-coordination of covalently bonded oxygen atoms [O(6), O(6)#1] of the methanesulfonate groups.     

Synthesis,Structure and Properties of N-(Thio)Phosphoryl Thiómides

Abstract

The analysis of all known synthesis methods of N-(thio)phosphorylthiómides of the common formula RC(S)NHP(X)R'₂ (1), where R=Alk, Ar; R'=óIk, ór, SAIk, SAr. Alk, Ar; X=O,S has been gave in this report. We worked out the simple and convenient syntheses methods of this class compounds.     

Syntheses, crystal structures, and physical properties of La5Cu6O4S7 and La5Cu6.33O4S7

Single crystal and bulk powder samples of the quaternary lanthanum copper oxysulfides La5Cu6.33O4S7 and La5Cu6O4S7 have been prepared by means of high-temperature sealed-tube reactions and spark plasma sintering, respectively. In the structure of La 5Cu6.33O4S7, Cu atoms tie together the fluorite-like (2)infinity[La5O4S(5+)] and antifluorite-like (2) infinity[Cu6S6(5-)] layers of La5Cu6O4S7. The optical band gap, E g, of 2.0 eV was deduced from both diffuse reflectance spectra on a bulk sample of La5Cu6O4S7 and for the (010) crystal face of a La 5Cu6.33O4S7 single crystal. Transport measurements at 298 K on a bulk sample of La 5Cu 6O 4S 7 indicated p-type metallic electrical conduction with sigma electrical =2.18 S cm(-1), whereas measurements on a La 5Cu6.33O4S7 single crystal led to sigma electrical =4.5 10(-3) S cm(-1) along [100] and to semiconducting behavior. In going from La 5Cu6O4S7 to La5Cu6.33O4S7, the disruption of the (2)infinity[Cu6S6(5-)] layer and the decrease in the overall Cu(2+)(3d(9)) concentration lead to a significant decrease in the electrical conductivity.     

A Coordination Polymer of Nickel(II) Based on a Pentadentate N, S, and O Donor Ligand

The synthesis, structural characterization, and electrochemical properties of a Ni(II) complex derived from the template reaction of N,N'-bis(2-mercaptoethyl)-1,5-diazacyclooctane nickel(II), Ni-1, with ICH(2)CO(2)Na are described. Blue N-(3-thiabutyl)-N'-(3-thiapentanoate)-1,5-diazacyclooctanenickel(II)iodide, [(tbtp-daco)Ni][I], [5]I, contains Ni(II) in an octahedral environment with N(2)S(2)O(2) donor atoms; one oxygen is from an adjacent [(tbtp-daco)Ni] ion and has the same distance to Ni(II) as the intramolecular oxygen, resulting in a coordination polymer. Complex [5]I.H(2)O, C(13)H(27)N(2)O(3)S(2)NiI, crystallizes in the orthorhombic space group Pbca with a = 10.898(3), b = 18.103(5), c = 19.020(5), and Z = 8. The extent to which the polymer is retained in solution is counterion dependent, which influences redox properties (accessibility of Ni(I) and Ni(III)).     

Structural characterization,photoluminescence, computational studies and bioassay of newly synthesized N-(3-oxo-3-morpholino-1-phenyl-propyl) benzo sulfonamide with multifunctional application

Research on Chemical Intermediates - N-(3-oxo-3-morpholino-1-phenyl-propyl) benzo sulfonamide (BMS) (C19H22N2O4S) has been synthesized and characterized by FT-IR, 1H and 13C NMR, and ESI-mass...     

Structures of the trisulfur oxides S3O and S3O.+: branched rings, not open chains

Higher-level ab initio calculations showed that the global energy minimum for both S3O and S3O.+ is a branched, three-membered ring, not an open chain form.     

Model for the Reduced Schiff Base Intermediate between Amino Acids and Pyridoxal: Copper(II) Complexes of N-(2-Hydroxybenzyl)amino Acids with Nonpolar Side Chains and the Crystal Structures of [Cu(N-(2-hydroxybenzyl)-D,L-alanine)(phen)].H(2)O and [Cu(N-(2-hydroxybenzyl)-D,L-alanine)(imidazole)

Copper(II) complexes with reduced Schiff base ligands of amino acids possessing nonpolar side chains with salicylaldehyde have been synthesized. Ternary complexes with imidazole, 1,10-phenanthroline, and pyridine have been prepared and characterized for N-(2-hydroxybenzyl)-D,L-alanine. The crystal structures of [(N-(2-hydroxybenzyl)-D,L-alanine)(1,10-phenanthroline)Cu(II)] monohydrate ([Cu(SAla)phen].H(2)O) and [(N-(2-hydroxybenzyl)-D,L-alanine)(imidazole)Cu(II)] ([Cu(SAla)Him]), have been determined. [Cu(SAla)phen].H(2)O crystallized in space group P&onemacr;, with a = 8.718(2) ?, b = 10.886(3) ?, c = 11.693(2) ?, alpha = 71.32(2) degrees, beta = 85.27(2) degrees, gamma = 70.21(2) degrees, and Z = 2. The copper atom is five coordinate, with SAla acting as a tridentate ONO chelator through the carboxylato and phenolato oxygens and the amine nitrogen. The remaining donors are provided by the phen nitrogens. [Cu(SAla)Him] crystallized in space group P2(1)/n, with a = 10.353(1) ?, b = 6.714(1) ?, c = 18.769(2) ?, beta = 91.71(1) degrees, and Z = 4. The copper atom is four coordinate, with SAla acting as a tridentate ONO chelator with the neutral imidazole moiety coordinated through nitrogen. In both complexes the ligand has two chiral centers due to the coordination of the N. Molecular mechanics calculations show that unfavorable steric interactions would occur in the nonobserved R,R and S,S diastereomers. Compounds prepared have been characterized by a range of physicochemical techniques. The complexes may serve as stable models for the intermediates in enzymatic amino acid transformations.     

N-对R苯基氮杂15冠5八钼多酸钠超分子配合物的合成与结构

为研究大环化合物对客体分子的选择性, 合成了通式为[NaL(Et2O)]2Na2Mo8O26的三种新型N-对R苯基氮杂15冠5八钼多酸钠超分子配合物(其中L分别为: N-苯基氮杂15冠5、N-对氯苯基氮杂15冠5和N-对甲苯基氮杂15冠5), 进行了元素分析, 红外光谱与核磁共振等结构参数的表征, 对R基为CH3的标题配合物作了X射线四圆衍射测定, 该晶体属单斜晶系, 空间群为P21/a,a=1.4590(4)nm, b=1.3817(3)nm, c=1.7639(5)nm, β=112.67(2)°, V=3.281(1)nm^3, Mr=2021.3, Dc=2.11g/cm^3,μ=2.37mm^-^1, F(000)=2048, R=0.045和Rw=0.057, 与[Na.(DB18C6)(CH3OH)M6O19和[Na(DB24C8)]2M6O19进行比较,结果表明: 大环化合物不仅对客体金属离子有分子识别性, 而且对与之抗衡的多酸阴离子也具有影响。     

Polysiloxane xerogels with a bifunctional surface layer containing O/N, O/S, S/N, and S/S donor centers

Formation of bifunctional xerogels containing -NH₂, -SH, -P(O)(OEt)₂, and -NHP(O,S)(OEt)₂ complexing groups in the surface layer was studied using sol-gel method (fluoride ion catalyst, ethanol solvent) and three-component systems.     

LC-MS analysis of the formed peptides from N-(O,O-diiso-propyl)phosphoryl aspartic acid

LC-ESI-MS method was used to analyze the formed di-and tri-peptide hi the reaction system of N-(O,O-diisopropyl)phosphoryl aspartic acid and adenosine.Ouster ions of the peptides were given hi the ESI-MS.The structures of these small peptides were confirmed by LC-MS-MS analysis.Compared with the traditional HPLC-UV detection,this method showed good sensitivity and selectivity for peptide in the presence of compounds with strong UV absorption,such as nucle-oside and nucleotide.     

Reversible disulfur monoxide (S2O)-forming retro-Diels-Alder reaction. disproportionation of S2O to trithio-ozone (S3) and sulfur dioxide (SO2) and reactivities of S2O and S3

5,6-Di-tert-butyl-2,3,7-trithiabicyclo[2.2.1]hept-5-ene 7-endo-oxide (4) was prepared by addition of S(2)Cl(2) to 3,4-di-tert-butylthiophene 1-oxide (3) in high yield. The oxidation of 4 with dimethyldioxirane gave a 7:1 isomeric mixture of 5,6-di-tert-butyl-2,3,7-trithiabicyclo[2.2.1]hept-5-ene 2-endo-7-endo-dioxide (5a) and 2-exo-7-endo-dioxide (5b) quantitatively. The thermally labile 5 was shown to undergo a retro-Diels-Alder reaction that produces S(2)O and 3 in a reversible way. The resulting S(2)O was trapped by Diels-Alder reactions with dienes to give 3,6-dihydro-1,2-dithiin 1-oxides in good yields. In the absence of the dienes, S(2)O disproportionates to SO(2) and S(3), and the resulting S(3) underwent a 1,3-dipolar cycloaddition with 3 on its syn-pi-face with respect to the S[double bond]O bond to give a trithiolane derivative, whereas in the presence of excess norbornene, it produced the 1,3-dipolar cycloadduct with norbornene in good yield. Thus, the retro-Diels-Alder reaction of 5 functions as an S(2)O and S(3) source. DFT calculations at the B3LYP/6-311+G(3df,2p) level were carried out in order to explain why S(2)O disproportionates to SO(2) and S(3) and why S(2)O acts as a dienophile and not a 1,3-dipole, whereas O(3) and S(3) serve as 1,3-dipoles.     

Theoretical study of isomerism in the molecules N2O,PNO, P2O,N2S,PNS, and P2S

We have carried out nonempirical calculations of the potential surface for isomeric rearrangements of the molecules N₂O, N₂S, PNO, PNS, P₂O, and P₂S. It was found that for the molecules N₂O and N₂S a linear structure is considerably more favorable than a cyclic one, which lies 60 kcal·mole^–1 higher and has low stability. For P₂O and P₂S the linear and cyclic isomers have similar energies. For PNO and PNS there are two linear isomers and one cyclic isomer. The isomers are separated by appreciable barriers and can exist independently. It is predicted for the ABC molecules with 16 valence electrons that if two or all three of the atoms belong to the third or a later period, then the cyclic isomers should be favored to at least the same extent as the linear isomers.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 794–802, April, 1990.     

Valence bond structures for the D2h isomer of N2O4 and some isomers of S3O2 and S3O

The construction of valence bond structures of the increased-valence type is re-described for the D2h isomer of N2O4 and applied to obtain the corresponding valence bond structures for isomers of S3O2 and S3O, each of which has at least one six-electron four-center bonding unit. It is discussed how the S-O and S-S bond properties that are associated with the S3O2 and S3O increased-valence structures are in qualitative accord with the calculated bond lengths. The qualitative six-electron four-center molecular orbital theory for the symmetrical O-S-S-O component of each S3O2 isomer is related to the increased-valence structure for the six electrons. An increased-valence structure for the lowest-energy S3O2 isomer is equivalent to a restricted form of resonance between 16 Lewis-type valence bond structures. The two types of S-S bond length are used to provide empirical estimates of the weights for these Lewis structures and are compared with those obtained from the results of STO-6G valence bond calculations for the 3Sigma- ground state of SO.