Nitrile sulfides. Synthesis of 1,2,4-thiadiazoles

Howe, Robert K.; Franz, John E.

doi:10.1021/jo00921a022

Cited by 57 publications

(29 citation statements)

References 5 publications

(8 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, we had previously obtained [21] cycloaddition products if alkynes [18] or phosphaalkynes [19] were used as trapping reagents. We were interested in investigating the thermolysis of the 2H-azaphosphirene complex 1 in the presence of dialkyl cyanamides.…”

Section: Resultsmentioning

confidence: 99%

“…In the synthesis of 2H-azirenes and so-called heteroazirenes (ring systems with two heteroatoms and a C ± N double bond), it is noteworthy that, apart from recently reported examples of [21] cycloadditions of carbenes to benzonitrile to give 2H-azirines, [6] no such reactions of either nitrenes or phosphini-denes (phosphanediyls) [7] with nitriles have been reported so far. Although only briefly reported, the reaction of a silylene derivative with benzonitrile affording the first stable [8] 2H-azasilirene was a real landmark (I: E SiR 2 ).…”

Section: Introductionmentioning

confidence: 99%

“…Nitrile concentration and the electronic influence of the nitrile substituent were examined with respect to reaction courses and product ratios. The quest for the generation of nitrilium phosphane ylide complexes will be discussed and examples of unprecedented [21] cycloadditions of a terminal phosphanediyl complex to a nitrile will be given.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Syntheses of 2H-1,3,2-Diazaphosphole, 2H-1,4,2-Diazaphosphole, and Δ3-1,3,2-Oxazaphospholene Complexes; First Examples of 2H-Azaphosphirene Complex Formation by [2+1] Cycloaddition

et al. 1998

View full text Add to dashboard Cite

Thermal ring-opening of {[2-bis(trimethylsilyl)methyl-3-phenyl-2H-azaphosphirene-kP]pentacarbonyltungsten(0)} (1) in the presence of various nitriles is investigated, in which toluene and/or the nitriles are used as solvents. In toluene, for example, the 3-(1-piperidino)-substituted 2H-azaphosphirene complex 5 b, 4-(1-piperidino)-5-phenyland 4,5-bis(1-piperidino)-substituted 2H-1,3,2-diazaphosphole complexes 6b,d are obtained if 1-piperidino nitrile (2 b) is employed as trapping reagent. Furthermore, a new three-component reaction is presented, using the 2H-azaphosphirene complex 1 and a mixture of two different nitriles, thus giving access to 4,5-mixed-substituted 2H-1,3,2-diazaphosphole complexes 6 a, b and 6 e ± h.The chemo-and regioselectivity of such reactions is rationalized by [32] cycloadditions of transiently formed C-dialkylamino-substituted nitrilium phosphane ylide complexes 3 b, c to nitriles. Use of two equivalents of dialkyl cyanamides and four equivalents of either ethyl cyanoformate or phenyl glyoxonitrile resulted in dual trapping reactions of complexes 3 b, c, forming 2H-1,3,2-diazaphosphole complexes 6 i ± k and D 3 -1,3,2-oxazaphospholene complexes 8 a ± g. Reaction of the 2H-azaphosphirene complex 1 with ethyl cyanoformate in toluene gave exclusively the 4,5-bis-(ethoxycarbonyl)-2H-1,3,2-diazaphosphole complex 6 l; even in benzonitrile, the mixed-substituted 2H-1,3,2-diazaphosphole complex 6 m is formed only as a by-product. The first 2H-1,4,2-diazaphosphole complex 9 was synthesized along with the regioisomeric 2H-1,3,2-diazaphosphole complex 6 n (ratio of 9:6 n: 6:1) through thermal ring-opening of 2H-azaphosphirene complex 1 in neat benzonitrile. The structures of 2H-1,3,2-diazaphosphole complex 6 c, 2R,5S-D 3 -1,3,2-oxazaphospholene complex 8 a and 2H-1,4,2-diazaphosphole complex 9 were determined by single-crystal X-ray diffraction.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Syntheses of 2H-1,3,2-Diazaphosphole, 2H-1,4,2-Diazaphosphole, and Δ3-1,3,2-Oxazaphospholene Complexes; First Examples of 2H-Azaphosphirene Complex Formation by [2+1] Cycloaddition

et al. 1998

View full text Add to dashboard Cite

show abstract

“…p-Tolunitrile sulfide 1b and benzoyl cyanide reacted similarly affording thiadiazole 5bd (78%, 88% by HPLC), together with p-toluonitrile and sulfur (12%) ( of adduct 5cd (27%) was obtained for acetonitrile sulfide. The reaction of benzonitrile sulfide with 2-furoyl cyanide, acetyl cyanide and 2-oxooctanonitrile was also examined and, using a 1:1 reactant ratio, thiadiazoles 5ae (77%), 5af (60%) and 5ag (17%) were isolated (Table, entries [4][5][6]. The yields of cycloadducts (77-91%) obtained from arenenitrile sulfides 1a/1b with aroyl cyanides 4d/4e are much greater than those reported 6 for the corresponding reaction with aryl cyanides, thus demonstrating the activating effect of the acyl substituent on the reactivity of the cyano group towards this class of 1,3-dipoles.…”

mentioning

confidence: 99%

“…The reaction of benzonitrile sulfide with 2-furoyl cyanide, acetyl cyanide and 2-oxooctanonitrile was also examined and, using a 1:1 reactant ratio, thiadiazoles 5ae (77%), 5af (60%) and 5ag (17%) were isolated (Table, entries [4][5][6]. The yields of cycloadducts (77-91%) obtained from arenenitrile sulfides 1a/1b with aroyl cyanides 4d/4e are much greater than those reported 6 for the corresponding reaction with aryl cyanides, thus demonstrating the activating effect of the acyl substituent on the reactivity of the cyano group towards this class of 1,3-dipoles. Similar yields of adducts have been reported for other activated nitriles including ethyl cyanoformate 3 and trichloroacetonitrile.…”

mentioning

confidence: 99%

Nitrile sulfides. Part 13.1 Synthesis of 5-acyl-1,2,4-thiadiazoles by cycloaddition of nitrile sulfides to acyl cyanides

McKie¹,

Paton²

2002

Arkivoc

View full text Add to dashboard Cite

The periselectivity of the nitrile sulfide cycloaddition to acyl cyanides has been examined. Benzonitrile sulfide, generated by thermal decarboxylation of 5-phenyl-1,3,4-oxathiazol-2-one, reacted exclusively at the cyano group of benzoyl cyanide to afford 5-benzoyl-3-phenyl-1,2,4-thiadiazole. Similar perispecificity was observed with p-toluonitrile sulfide and acetonitrile sulfide, and for cycloaddition of benzonitrile sulfide to 2-furoyl cyanide, acetyl cyanide and 2-oxooctanonitrile. The reactivity of benzoyl cyanide as a dipolarophile was shown to be similar to that of ethyl cyanoformate in a competition experiment which afforded a 51:49 mixture of 5-benzoyl-and 5-ethoxycarbonyl-3-phenyl-1,2,4-thiadiazoles.

show abstract

Thiadiazoles

Chiacchio

Romeo

2011

Modern Heterocyclic Chemistry

View full text Add to dashboard Cite

Nitrile sulfides. Synthesis of 1,2,4-thiadiazoles

Cited by 57 publications

References 5 publications

Syntheses of 2H-1,3,2-Diazaphosphole, 2H-1,4,2-Diazaphosphole, and Δ3-1,3,2-Oxazaphospholene Complexes; First Examples of 2H-Azaphosphirene Complex Formation by [2+1] Cycloaddition

Syntheses of 2H-1,3,2-Diazaphosphole, 2H-1,4,2-Diazaphosphole, and Δ3-1,3,2-Oxazaphospholene Complexes; First Examples of 2H-Azaphosphirene Complex Formation by [2+1] Cycloaddition

Nitrile sulfides. Part 13.1 Synthesis of 5-acyl-1,2,4-thiadiazoles by cycloaddition of nitrile sulfides to acyl cyanides

Thiadiazoles

Contact Info

Product

Resources

About