Type K Syntheses

Type K (C—C—N—C—S) Syntheses.—Further examples of the dehydrative cyclization, by means of dicyclohexylcarbodi-imide, of N-benzyloxythio-carbonylamino-acids (109) to 2-benzyloxy-A -thiazolin-5-ones (110) have been reported. Compared with 2-phenyl-A -thiazolin-5-ones, the products show a greatly diminished tendency to enolization, probably attributable to the inductive effect of their benzyloxy-group. Their oxidation by iodine produces the corresponding 4,4 -bis-(2-benzyloxy-A -thiazolin-5-ones) 

Photolysis at 253.7 nm in acetonitrile of 2,4- or 2,5-dimethyl-A -thiazoline gives the same products, namely mixtures of the iV-alkenyl-thioamides MeC(S)NH-CHaCMe=CHa and MeC(S)NHCH=CHMe, apparently via the same intermediate, namely the aziridine valence-bond isomer (69) (see Vol. 3, p. 587).  

Other substituted A -thiazolines behave similarly, although compounds with a 2-substituent (e.g. Ph, CH=CHPh, SH, or 3-pyridyl) conjugated with the double bond in the ring are inert. These results explain why indoline, dihydrobenzo-furans, and dihydroanthracenes are capable of being photoaromatized by excited 

Johnson, A. Nakanishi, N. Nakanishi, and K. Tanaka, Tetrahedron Letters, 1975, 

Okutome, Y. Sakurai, M. Kurumi, H. Kawamura, S. Sato, and K. Yamaguchi, Chem. and 

4-Alkyl-5-sulphonylimino-l,2,3,4 thiatriazolines react by cycloaddition with ynamines, with subsequent loss of nitrogen, to give A -thiazolines, e.g. (87) (88 = Me, R = NEta). The reaction is regiospecific, in that the amine 

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Type K Syntheses (C—C—N—C—S). The reaction between jS-(ethoxycar-bonyl)acryloyl isothiocyanates (obtained from the acid chloride and lead thiocyanate) and aromatic amines gives the 2-arylamino-A -thiazolin-4-ones (48) in good yield.2-(Substituted amino)-A -thiazolines may also be obtained in high yields by allowing vicinal iodo-isothiocyanates to react with amines e.g. PhCH(NCS)CH2l with amines, in the absence of light, gives (49). ... 

Type K Syntheses (C—C—N—C—S).—1,2-Dichloroethyl isothiocyanate reacts with thioureas to give thiadiazines, at room temperature, or thiazoles (11) at 80—100 °C. The former rearrange to the latter on heating or in the presence of base. With ureas, the only ureido-derivative isolated corresponded to (11 Ri = H, R = R = Me). ... 

Type K Syntheses (S-C-N-C-C). With SnCl2, 4,4-bistrifluoromethyl-1-thia-3-aza-1, 3-butadienes (86) cyclise to (87) which with nucleophiles form C-5 substituted products. The I.R., H, C and F... 

Type K Syntheses (C-C-N-C-S). of CICH2CH2NCS to 2-arylhydrazinothiazolines (115 Z=NHNH,R =Ar). The latter can be oxidised with H2O2 to azo compounds (115 Z= N=N, R =Ar) 37 similar method has been used to separate, as derivatives, otherwise inseparable mixtures of isomeric vic-iodoiso-thiocyanates (. 1l6- 117) [Scheme 5l. Diagnostic differences in... 

Type K Syntheses (S-C-N-C-C). Cyclisation of (158) to 2-arylimino-thiazolidines (159 R=aIkyl,alkylthio,alkenyl,cyclopropyl,Ph,PhO, PhNHCO,halogen,r r = H,alkyl,halogen or ring) occurs with HCl/H O ... 

Thermal Conductivity. The value of 2000 W/(m-K) at room temperature for Type Ila natural stones is about five times that of Cu, and recent data on 99.9% isotopicaHy pure Type Ila synthesized crystals ate in the range of 3300—3500 W/(m-K) (35). This property combined with the high electrical resistance makes diamond an attractive material for heat sinks for electronic devices. 

Cyclooctatetraenyl derivatives of the rare earths were synthesized shortly after the characterization of uranocene first for europium and ytterbium in the oxidation state R by Hayes and Thomas (1969a). But one year later, Mares et al. (1970) prepared complexes of the type K[R(Cj,Hg)2], where R = Ce, Pr, Nd, Sm, and Tb. The corresponding yttrium, lanthanum and gadolinium derivatives are described by Hodgson et al. (1973) and the scandium compound was made by Westerhof and De Liefde Meijer in 1976 ... 

Type K (C—C—N—C—S) Syntheses.— The adduct of allyl isothiocyanate and dimethyl malonate cyclizes in the presence of halogen (Cla, Bra, or I2) to give... 

TT-Electron materials, which are defined as those having extended Jt-electron clouds in the solid state, have various peculiar properties such as high electron mobility and chemical/biological activities. We have developed a set of techniques for synthesizing carbonaceous K-electron materials, especially crystalline graphite and carbon nanotubes, at temperatures below 1000°C. We have also revealed new types of physical or chemical interactions between Jt-electron materials and various other materials. The unique interactions found in various Jt-electron materials, especially carbon nanotubes, will lay the foundation for developing novel functional, electronic devices in the next generation. 

The MoFe proteins are all a2 2 tetramers of 220-240 kDa, the a and (3 subunits being encoded by the nifD and K genes, respectively. The proteins can be described as dimers of a(3 dimers. They contain two unique metallosulfur clusters the MoFeTSg homocitrate, FeMo-cofactors (FeMoco), and the FesSy, P clusters. Neither of these two types of cluster has been observed elsewhere in biology, nor have they been synthesized chemically. Each molecule of fully active MoFe protein contains two of each type of cluster 2-7). 

Jorgensen, C. K. Heavy Elements Synthesized in Supernovae and Detected in Peculiar A-type Stars. Vol. 73, pp. 199-226. 

HEAVY ALKYNE ANION RADICALS The Only example of Compounds of this type, the anion radical of the valence isomer of distannyne 51-K, was recently synthesized by Power by the reduction of chlorostannylene 52 with potassium graphite in THF (Scheme 2.39). ... 

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