Sodium naphthalenide reductive cleavage

Primary ally lie amines1 In the presence of this catalyst, allylic chlorides or acetates react with sodium p-toluenesulfonamide in THF/DMSO (80 20) to form the corresponding allylic sulfonamide in 60-85% yield. The products are converted into primary allylic amines on reductive cleavage (sodium naphthalenide). 

Reductive cleavage of sulfonamides.2 Sodium naphthalenide can be used for this reaction, but it does not cleave mesyl amides of primary and dialkyl amines. A wide variety of sulfonamides is cleaved with potassium and dicyclohexyl-18-crown-6. 

Simple chiral phosphines have already been mentioned (Section 3.1.3) and the macrocycle enantiomers are discussed below (Section 4.6). Current research in this area is concentrated on bidentate chiral phosphines, such as the ligands (24)-(27). Although their transition metal complexes are normally used for stereospecific synthesis, Whitmire and coworkers used the molybdenum complexes to resolve their racemic bisphosphines via flash chromatography. The phosphines were decomplexed by reductive cleavage at low temperatures (-78 °C) using sodium naphthalenide (Scheme 1). 

A novel electron transfer free radical mechanism has been elucidated for sodium naphthalenide induced demercuration. A new reductant for the cleavage of the C—Hg bond, A -benzyl-1,4-dihydro-nicotinamide (BNAH), has also been proposed it reduces alkylmercury(II) acetates via an electron transfer chain substitution mechanism. ... 

Reductions of l,l-biphenylene-2-methylcyclopropane 119 with Na/NHs, Na/NHs/r-BuOH, Li/NHs, electrolysis, Na/glyme and sodium naphthalenide/glyme/25°( —78°C) essentially confirm the results with 49, although under any conditions a higher ratio of C(l)-C(2) bond cleavage is observed in the case of 119 ... 

A similar strategy was employed to assemble the tetramer 32 which features four central phosphole units and four peripheral phosphinine rings. Importantly, reduction of this oligomer with 4 equiv. of sodium naphthalenide sodium resulted in the cleavage of the two P-P bonds and formation of the phospholide anions. This dianionic species was found to be sufficiently stable to be characterized. Trapping reaction of dianion 33 with methyl iodide afforded the tetradentate ligand 34 (Scheme 9). 

Radicals can also be generated via the fragmentation of radical anions. Single electron reduction of various alkyl or aryl halides will lead to bond cleavage, as shown in Eqs. 10.44 and 10.45. The reductions commonly occur from dissolving metals such as Na and K, sodium naphthalenide (Na Ar ), sodium benzophenone ketyl, or from pulse radiolysis (e ). 

We discovered a complementary procedure for conversion of OMen to other functional groups. The ester P-OMen bond was shown to be cleaved in a stereoselective manner reductively [85,86]. The cleavage takes place with almost complete preservation of stereochemical integrity at phosphorus. The reducing agents are usually sodium or Hthium naphthalenide, lithium biphenyUde, and Hthium 4,4 -di-fert-butylbiphenyl (LDBB). The species produced is then quenched with an alkyl hahde or methanol to afford tertiary or secondary phosphines, respectively (Scheme 5b). Overall, the displacement reaction proceeds with retention of configuration. 

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