Sodium in liquid ammonia

Nitrogen oxide does show some ability to gain an electron and when passed into a solution of sodium in liquid ammonia, the... 

Monosodium acetylide may also be prepared by the reaction of acetylene with sodium In liquid ammonia ... 

The benzyl group has been widely used for the protection of hydroxyl functions in carbohydrate and nucleotide chemistry (C.M. McCloskey, 1957 C.B. Reese, 1965 B.E. Griffin, 1966). A common benzylation procedure involves heating with neat benzyl chloride and strong bases. A milder procedure is the reaction in DMF solution at room temperatiue with the aid of silver oxide (E. Reinefeld, 1971). Benzyl ethers are not affected by hydroxides and are stable towards oxidants (e.g. periodate, lead tetraacetate), LiAIH, amd weak acids. They are, however, readily cleaved in neutral solution at room temperature by palladium-catalyzed bydrogenolysis (S. Tejima, 1963) or by sodium in liquid ammonia or alcohols (E.J. Rcist, 1964). 

Methylthio- and 2-ethylthio-4-methylthiazoles undergo reductive ring opening when treated by sodium in liquid ammonia (204). The first step of this reaction consists of the formation of the A-4-thiazoline anion (80). The next steps are analogous to those given for 80a to 83. 

An aryl methanesulfonate was cleaved to a phenol by phenyllithium or phen-ylmagnesium bromide it was reduced to an aromatic hydrocarbon by sodium in liquid ammonia. ... 

Weiss ° treated 16-dehydro- (6), 17a-acetoxy- (8), 17a-hydroxy- (9) and 17a-bromopregnan-20-one (11) with a solution of lithium, barium, calcium or sodium in liquid ammonia and reacted the intermediate enolate anion (7) with the appropriate alkyl halide. 

Cyclic enamines can also be obtained by the reduction of pyridine and isoquinoline with lithium aluminum hydride (163-165), and the latter reduction has also been accomplished with sodium in liquid ammonia (166). 

Reduction of the enamine system of an aminostilbene by sodium in liquid ammonia 189) and of a 17-enaminosteroid by aluminum and mercuric chloride in alcohol 560) have also been reported. 

Catalytic hydrogenation of alkynes on a metal surface provides cis alkenes (see Chapter 7, Problem 13), while treatment with sodium in liquid ammonia nearly always leads to trans alkenes, e.g., hydrogenation of 2-butyne. 

Thiophenethiols are prepared by reduction of the sulfonyl chlorides or, more conveniently, by the reaction of Grignard rea-gents or thienyllithium compounds with sulfur. They have also been obtained by cleavage or thienyl alkyl sulfides with sodium in liquid ammonia. 3-Thiophenethiol is a by-product in the commercial thiophene synthesis. Thiophenethiols have recently also been prepared by a synthesis involving Friedel-Crafts reaction of 2,4-dinitrobenzenesulfenyl chloride with thiophenes, followed by basic cleavage of the resulting sulfide. ... 

Chloro-3,4-dimethylthiazolium tetrafluoroborate and 3-methyl-2-chlor-obenzothiazolium tetrafluoroborate and [Os3(CO)i2] in the presence of sodium in liquid ammonia give the neutral carbene complexes 37 and... 

In another approach to analogs, nortestosterone is first converted to the thioketal by treatment with ethylene dithiol in IUe presence of boron trifluoride. (The mild conditions of this reaction compared to those usually employed in preparing the oxygen ketals probably accounts for the double bond remaining at 4,5.) Treatment of this derivative with sodium in liquid ammonia... 

To a suspension of sodamide in liquid ammonia and made from sodium in liquid ammonia, there is added fractionally and with stirring phenothiazine. After an hour there is added thereto, while maintaining the stirring, 1-chloro-2-methyl-3-bromopropane, then 700 cc of toluene. The ammonia is then driven off and heating under reflux is carried out for one hour. 

Polytetrafluorethylene (p.t.f.e.) This polymer does not absorb water, has no solvents and is almost completely inert to chemical attack molten alkali metals and sodium in liquid ammonia are the rare exceptions. Furthermore it does not soften below 320°C, is electrically inert and has a very low coefficient of friction. It is more expensive than general purpose plastics, requires special fabrication techniques, is degraded by high energy radiation, and has a low creep resistance. 

Truce also examined a few examples of the cleavage of sulphones with sodium in liquid ammonia97 and found essentially similar results except that diaryl sulphones were reduced to sulphinate salts instead of to arylthiolates as with the lithium reductions. Dialkyl sulphones were unreactive towards sodium in liquid ammonia. 

Relatively few reports have been published subsequently on the use of these reagents. Hope and coworkers99 have used sodium in liquid ammonia to cleave the benzyl sulphonyl derivatives of cysteamine, L-cysteine and L-homocysteine to prepare the corresponding sulphinic acids, as in equation (42). 

Cross-hnked polyacrylamides are a group of hydrophihc solid supports introduced primarily for preparation of biopolymers (Fig. 4). Unhke PS resins, polyacrylamides have excellent swelling capacity in both protic (water, alcohols) and aprotic (dichloromethane, dimethylformamide) solvents [88]. These beads are stable towards bases, acids, and weak reducing and oxidizing agents [89]. Predictably, conditions under which amide bonds are cleaved (i.e., sodium in liquid ammonia) [90] lead to rapid decomposition of the polymer. 

The inertness of ordinary double bonds toward metallie hydrides is quite useful, since it permits reduction of, say, a carbonyl or nitro group, without disturbing a double bond in the same molecule (see Chapter 19 for a discussion of selectivity in reduction reactions). Sodium in liquid ammonia also does not reduce ordinary double bonds, although it does reduce alkynes, allenes, conjugated dienes, and aromatic rings (15-14). 

Reduction of (24) by Lindlaar hydrogenation gives a cis double bond and sodium in liquid ammonia gives the trans double bond,... 

Natural products citronellal (35) and linalool (36) have the same skeleton as (34). Hydrogenation of linalool gave alcohol (37). Dehydration and hydrogenation would be the obvious way to make (34) from (37) but an alternative was used here. The halide (38) was reduced with sodium in liquid ammonia. 

Rather than reduce (10) with sodium in liquid ammonia (p T 127), these workers preferred to make the ais compound and isomerise it to the more stable tvans (9) by light. 

Sharpless reaction of the enantiomeric alkenes (47) produced the precursors for 2-amino-2-deoxy-o -D and -L-carba-glucopyranoses. These compounds were converted into the penta-7V,0-acetates by the following sequence. Replacement of the bromo group with an acetate ion, treatment with sodium in liquid ammonia, and peracetylation. 

Coupling of 237 with the protected 2-amino-2-deoxy-o -D-glucopyranosyl bromide (348) in dichloromethane in the presence of silver triflate afforded a diastereoisomeric mixture. The isomer related to the natural one was depro-tected with sodium in liquid ammonia, to give the carba-trehalosamine... 

The ditertiary phosphines (11), prepared from the corresponding alkyl chloride and lithium diphenylphosphide (10), - react with sodium in liquid ammonia to give the phosphines (12). 

Events of electron photoemission from a metal into an aqueous solution had first been documented in 1966 by Geoffrey C. Barker and Arthur W. Gardner on the basis of indirect experimental evidence. The formation of solvated electrons in nonaque-ous solutions (e.g., following the dissolution of metallic sodium in liquid ammonia) had long been known, but it was only in the beginning of the 1950s that their existence in aqueous solutions was first thought possible. It is probably for this reason that even nowadays in aqueous solutions we more often find the term solvated than hydrated electrons. 

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