Heteroatom Chemistry

doi: 10.1002/hc.520070101pmid: N/A

McEwen, William E.

doi: 10.1002/hc.520070102pmid: N/A

Yu, Zhengkun; Wang, Shihua; Yan, Shenggang

doi: 10.1002/(SICI)1098-1071(199601)7:1<3::AID-HC1>3.0.CO;2-Ipmid: N/A

Ten di‐n‐butyltin(I∇) carboxylates ((nBu2Sn‐OCOR′)2O)2 and nBu2Sn(OCOR′)2 (R′ = CCl3, CHCl2, CH2Cl, PhCH = CH, and 2,2,3,3‐tetramethylcyclopropyl) were synthesized and characterized by IR, 1H, 13C, 119Sn NMR spectroscopy and elemental analysis. Together with other series of organotin(I∇) carboxylates, their structural features were discussed. The relationship between the 119Sn NMR chemical shifts in the organotin(I∇) carboxylates ((nBu2SnOCOR′)2O)2, nBu2Sn(OCOR′)2, nBu3SnOCOR′, Ph3SnOCOR′ and the pKa values of their parent acids R′COOH was studied. The results have shown that the log(‐δ(119Sn)) of the same series of carboxylates is linearly related to the pKa of R′COOH. It seems that the better is the linearity between the log(−δ(119Sn)) and the pKa, the more analogous are the structures of the same series of carboxylates. © 1996 John Wiley & Sons, Inc.

Lane, Thomas M.; Levsen, Steven M.; Tasz, Maciej K.; Cremer, Sheldon E.; Hussain, M. Sakhawat; Mazhar‐ul‐Haque, M. Sakhawat

doi: 10.1002/(SICI)1098-1071(199601)7:1<9::AID-HC2>3.0.CO;2-Cpmid: N/A

The crystal structure of the title compound, diphenyl 1‐hydroxy‐1‐phenylethylphosphonate (1), was determined by the single‐crystal X‐ray diffraction method. The crystallographic data for 1 are as follow: C20H19O4P, Mr = 354.34, monoclinic, P21/n, a = 9.787(1) Å, b = 20.235(1) Å, c = 9.797(1) Å, β = 106.18(3)°, V = 1863.3(4) Å3, Z = 4, Dcalc = 1.26 g/cm3, λ(Mo‐Ka) = 0.71073 Å, μ = 1.6 cm−1, F(000) = 744, R = 0.018, and Rw = 0.032 for 2258 observed reflections. The solid‐state structure in a dimeric packing mode exhibits intermolecular hydrogen bonding of the type P = O···H–O. Infrared solution studies (CCl4) indicate that upon high dilution (10−4 M) the dimers completely dissociate to give conformers with and without intramolecular hydrogen bonds. Theoretical studies (PM3) were undertaken to determine the energy profile about the P–C torsional angle, which exhibited low energy barriers to rotation with no clear minimum energy conformation. © 1996 John Wiley & Sons, Inc.

Shanmugasundaram, Palanisamy; Murugan, Periyasamy; Ramakrishnan, Vayalakkavoor T.; Srividya, Narayanan; Ramamurthy, Perumal

doi: 10.1002/(SICI)1098-1071(199601)7:1<17::AID-HC3>3.0.CO;2-#pmid: N/A

Synthesis of 9‐alkyl, 10‐alkyl, 9,10‐dialkyl, and 10‐aryl‐3,4,6,7,9,10‐hexahydro‐1,8(2H,5H)acridinedione (2a–r) are described as a new class of laser dyes. Reactions of diamines with methylene bis(cyclohexane‐1,3‐dione) yielded the respective bisacridinediones (3a–e). These dyes lase around 478–494 nm and are compared with the standard dye coumarin‐102. © 1996 John Wiley & Sons, Inc.

Yoshifuji, Masaaki; Ito, Shigekazu; Toyota, Kozo; Yasunami, Masafumi

doi: 10.1002/(SICI)1098-1071(199601)7:1<23::AID-HC4>3.0.CO;2-3pmid: N/A

2,4‐Di‐t‐butyl‐6‐methylphenylphosphonous dichloride reacted with chloroform in the presence of lithium diisopropylamide to give (2,4‐di‐t‐butyl‐6‐methylphenyl) (dichloromethyl) (1,2,2‐trichloroethenyl)phosphine. The structure of this phosphine was analyzed by X‐ray crystallography. This phosphine further reacted with butyllithium to give (1‐butylpentylidene)(2,4‐di‐t‐butyl‐6‐methylphenyl)phosphine bearing a low‐coordinated phosphorus atom. © 1996 John Wiley & Sons, Inc.

Kandeel, Zaghloul El‐Shahat

doi: 10.1002/(SICI)1098-1071(199601)7:1<29::AID-HC5>3.0.CO;2-Ypmid: N/A

A simple route to the synthesis of the pharmaceutically important thieno(2,3‐d)pyrimidine derivatives and of thieno(2,3‐b)pyridine derivatives via the use of 5‐amino‐3‐phenylthiophene‐2,4‐dicarbonitrile (2) as a starting material is described. © 1996 John Wiley & Sons, Inc.

Kandeel, Zaghloul E.; Farag, Ahmad M.; Shaaban, Mohamed R.; Elnagdi, Mohamed H.

doi: 10.1002/(SICI)1098-1071(199601)7:1<35::AID-HC6>3.0.CO;2-1pmid: N/A

A facile, one‐step synthesis of 2‐amino‐5‐oxo‐5,6,7,8‐tetrahydro‐4H‐benzopyran derivatives 4a‐e via cyclo‐addition reactions of acrylonitrile derivatives 1a‐e with 1,3‐cyclohexandione 2 is described. On the other hand, the reactions of 2 with the thioamides 1f‐h afforded 5‐oxo‐5,6,7,8‐tetrahydroquinoline derivatives 9a‐c in good yields. The structures of the prepared compounds were established from their elemental analyses, spectroscopic data, and by their chemical transformations. © 1996 John Wiley & Sons, Inc.

BelBruno, Joseph J.

doi: 10.1002/(SICI)1098-1071(199601)7:1<39::AID-HC7>3.0.CO;2-Ypmid: N/A

The heights of the rotational barriers of the diselenide bridge in dimethyl diselenide have been calculated at the Hartree‐Fock level with the 3‐21G basis set. The minimum in the rotational potential energy function occurs at a torsional angle of 85.64°. The barriers were determined by complete geometry optimization at each point along the potential surface. The results are compared with other calculations and with the available experimental results. © 1996 John Wiley & Sons, Inc.

Wu, Shihui; Luo, Yumei; Liu, Fei; Chen, Shiming

doi: 10.1002/(SICI)1098-1071(199601)7:1<45::AID-HC8>3.0.CO;2-1pmid: N/A

The synthesis of di(α‐thienyl)hexamethyltrisilane (1) is described. In the photolysis of 1 with cyclohexene and methanol, an apparent radical reaction occurred. We suspect that the sulfur atom of the thienyl group strongly stabilizes an initially formed silyl radical. This idea was supported both by identifying typical radical reaction products and examining the ESR spectrum of an adduct obtained by use of a radical trap. © 1996 John Wiley & Sons, Inc.