Photolytic synthesis

The photolytic synthesis of 372 proceeds as follows a-Benzylidene-y-bu-tyrolactone (1.0 g, m.p. 115-117 °C) was evenly spread on the inner wall of a... 

A synthesis of homomoschatoline (1,2,3-trimethoxyoxoaporphine) via a Reissert intermediate and Pschorr cyclization has been described/ and a photolytic synthesis of atheroline (l,2,10-trimethoxy-9-hydroxyoxoaporphine) is now available/ The u.v. spectra of oxoaporphines are strongly dependent on the solvent used. ... 

Scheme 14 Photolytic synthesis of the bridging borylene rhenium complex 33...

O-demethylsalutaridine (43e), and sinoacutine (43a) have been synthesized (480). Kametani et al. (455, 481-487) synthesized them either by oxidation with potassium ferricyanide, Ag2C03, electrolytic oxidation, photolytic synthesis, or by the benzyne reaction. All these reactions (yield 1-5%) and... 

These data are in good agreement with the observations of Lowe and Ridley [65,66], who encountered difficulties in the photolytic synthesis and purification of another heptam (113). Furthermore, the observed sluggishness of the corresponding octams in the attempted acid hydrolysis can be considered a result of the almost planar 3-lactam nitrogen bonding in these systems [76]. On the other hand, these data show a tendency similar to that obtained by Moll... 

Photolysis of [Fe(C0)2(N0)2] in 1-butene doped liquid xenon affords [FelCO),. (NO)p(n-l-butene) J (x=l or 2) the photolytic synthesis of [Fe(depe)2(n-ethene)] from cis-EFeCHlpldepelol and ethene proceeds via the intermediacy of cis-[Fe(H)(n CH=CH2)(depe)2], Crystallographically... 

Figure 154. Photolytic synthesis of [Fe(S2CNEt2)2(dppe)] from [Fe(S2CNEt2)3] and dppe.

Synthesis of the title compound is representative of a number of syntheses of nonaromatic nitrogen heterocycles via Pd(Ill-catalyzed amination of olefins. These tosylated enamines are not readily available by standard synthetic methods, and show potential for further functionalization of the heterocycle. The saturated amine can be synthesized from the title compound by hydrogenation of the double bond followed by photolytic deprotection. ... 

The photolytic and thermolytic decomposition of azides in the presence of olefins has been applied to aziridine synthesis. However, only a limited number of steroid aziridines have been prepared in this manner. The patent literature reports the use of cyanogen azide at ca. 50° for 24 hours in ethyl acetate for the preparation of an A-nor- and a B-norsteroidal aziridine. The addition is believed to proceed via a triazoline. The reaction of cholest-2-ene with ethyl azidoformate takes place in a nonselective manner to produce a mixture of substances, including C—H insertion products. 

For a review covering the photolytic removal of protective groups, see V. N. R. Pillai, Synthesis, 1 (1980). 

Equations 1-10 illustrate some mild methods that can be used to cleave amides. Equations 1 and 2 indicate the conditions that were used by Woodward and Eschenmoser, respectively, in their synthesis of vitamin B12. Butyl nitrite, nitrosyl chloride, and nitrosonium tetrafluoroborate (NO BF4 ) have also been used to cleave amides. Since only tertiary amides are cleaved by potassium -butoxide (eq. 3), this method can be used to effect selective cleavage of tertiary amides in the presence of primary or secondary amides.(Esters, however, are cleaved by similar conditions.) Photolytic cleavage of nitro amides (eq. 4) is discussed in a review. 

Photolytic Dediazoniations and their Applications in Synthesis and in Image Technology 277... 

Thiazepinones, as photolytic products 883 Thiazine 1-oxides, synthesis of 323, 352 Thiene dioxides formula of 382 synthesis of 469 Thiene oxides formula of 382 synthesis of 469... 

Side-chain photochlorination of toluene isocyanates yields important industrial intermediates for polyurethane synthesis, one of the most important classes of polymers [6]. The motivation for micro-channel processing stems mainly from enhancing the performance of the photo process. Illuminated thin liquid layers should have much higher photon efficiency (quantum yield) than given for conventional processing. In turn, this may lead to the use of low-intensity light sources and considerably decrease the energy consumption for a photolytic process [6] (see also [21]). 

Scheme 10.14 gives some other examples of Wolff rearrangement reactions. Entries 1 and 2 are reactions carried out under the classical silver ion catalysis conditions. Entry 3 is an example of a thermolysis. Entries 4 to 7 are ring contractions done under photolytic conditions. Entry 8, done using a silver catalyst, was a step in the synthesis of macbecin, an antitumor antibiotic. Entry 9, a step in the synthesis of a drug candidate, illustrates direct formation of an amide by trapping the ketene intermediate with an amine. 

Photolytic [4+2] cycloreversion of a disilabicyclo[2.2.2]octadiene precursor is considered to be a general method for the synthesis of disilenes of varying stability. Several examples of this method have been reported (Eq. 9).27-31 First used in reactions producing an unstable disilene, Me2 Si=SiMe2,27 this method is also successful for synthesizing the marginally stable -Bu2Si=Si(t-Bu)2,28 However, it has not yet been applied to the synthesis of disilenes that are fully stable at room temperature, probably because the appropriate precursors are inaccessible. 

Metal carbonyl compounds are other suitable precursors for the synthesis of NPs by thermal decomposition. The main advantage is the formation of CO that is expelled from the IL phase due to its poor solubility. However, high temperatures are commonly used to decompose such precursors. Metal NPs of Cr(0), Mo(0), and W(0) were prepared by thermal or photolytic decomposition of their respective monometallic carbonyl compounds [M(CO)6] dispersed in ILs [52]. Similarly, the precursors [Fe2(CO)9], [Ru3(CO)i2], and [Os3(CO)12] were employed in order to obtain stable metal NPs (1.5-2.5 nm) in BMI.BF4 [53]. The same procedure was extended to the preparation of lr(0), Rh(0), and Co(0) NPs in ILs [54]. 

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