The preparation of a solubilized form of Lawessons reagent and its thionation reactions

Foreman, Mark; Slawin, Alexandra M. Z.; Woollins, J. Derek

doi:10.1002/(sici)1098-1071(1999)10:7<651::aid-hc21>3.0.co;2-7

Cited by 19 publications

(16 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Solubility problems are often an issue with Lawesson's reagent, and several attempts have been made to develop alternative reagents, based on, for example, introduction of a tert-butoxy group in the position ortho to the methoxy group in Lawesson's reagent. 13 Even fluorous variants have been developed. 14 Interestingly P 4 S 10 is considered to participate in a similar dissociation to the powerful thionation agent P 2 S 5 (Scheme 3); 15,16 calculations also support this view.…”

Section: Methodsmentioning

confidence: 99%

Comparison of Two Reagents for Thionations

Bergman

2018

Synthesis

View full text Add to dashboard Cite

Pyridine reacts readily with P4S10 to form a reagent with the composition C10H10N2P2S5 that is useful for thionations of amides. The thionating properties of this reagent are compared with those of Lawesson’s reagent.1 Introduction2 Development of C10H10N2P2S5 3 Use of Thionation for Modification of Biologically Active Compounds3.1 Thionations of Peptides3.2 Thionated Compounds of Interest as Potential Antivirals3.3 Thionations of Thalidomide and Related Molecules4 Comparison of Lawesson’s Reagent and C10H10N2P2S5

show abstract

Section: Methodsmentioning

confidence: 99%

Comparison of Two Reagents for Thionations

Bergman

2018

Synthesis

View full text Add to dashboard Cite

show abstract

“…LR* was synthesised according to the literature procedure 35 and the purity determined by 1 H and 31 P-{ 1 H} NMR. Solvents used were distilled over standard drying agents under nitrogen before use.…”

Section: Methodsmentioning

confidence: 99%

“…34 We found however that the target macrocycles 5 were temperature sensitive and a gentler thionation reagent was required. Woollins et al 35 Macrocycle 5b was produced in 16% yield whilst 7b was obtained in 51% yield. The successful synthesis of a finite yield of macrocycle 5b suggested that all or most of macrocycle 7b would be fully converted to 5b given sufficient time, thionation reagent and energetic input.…”

Section: (V) Thionation Of Preformed Macrocyclementioning

confidence: 98%

“…7,11-Diethyl-2,3-dithio-1,4,7,11-tetraazacyclotridecane (15.0 mg, 0.05 mmol, 5.4%) was eluted as the third fraction (rf 0.43) as an air sensitive orange powder upon removal of the solvent and drying under vacuum. 1 Applying standard Schlenk techniques, freshly prepared 35 2,4bis(3-tert-butyl-4-methoxyphenyl) 1,3,2,4-dithiadiphosphetane-2,4-disulfide (LR*) (56 mg, 0.1 mmol) and 7,11-diethyl-2,3dioxo-1,4,7,11-tetraazacyclotridecane (3b) (27 mg, 0.1 mmol) were dissolved in dry degassed DCM (3 mL). The mixture was stirred at room temperature for 3 days and monitored by TLC (silica/methanol).…”

Section: 11-diethyl-23-dioxo-14711-tetraazacyclotridecane (3b)mentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of nitrogen and sulfur macrocycles with cis exogenous oxygen and sulfur donor atoms

2005

View full text Add to dashboard Cite

A series of new N4 and N8 macrocycles has been prepared, that includes cis-exogenous O2, S2 and S/O atoms to allow chelation to a metal external to the macrocyclic ring. We found that thioamide units within the macrocycles were unstable to attack by secondary amines and thus alkylated precursors containing only tertiary amines could lead to exogenous-S2 macrocycles. Cyclisation of alkylated tetraamine precursors with dimethyloxalate or dithiooxamide led to both N4 and N8 macrocycles via 1 + 1 and 2 + 2 cyclisation reactions with exogenous-O2 or S2 respectively. Alkylation of preformed exogenous-O2 macrocycles was explored and led to alkyl substitution at the secondary amine nitrogens in the ring, however synthesis of these species was overall lower yielding than cyclisation using alkylated tetraamine precursors. Thionation of an exo-O2 macrocycle using an analogue of Lawesson's Reagent led to formation of the analogous exogenous-S2 and exogenous-O,S macrocycles. Related S2N2 macrocycles with exogenous-O2 were prepared by a cyclisation route but could not be isolated free of larger ring analogues.

show abstract

“…18 Cherkasov et al included LR in their review about organothiophosphorus reagents. 19 Starting from these and other reviews [20][21][22][23][24][25][26][27] we re-examine the developments in the application of this powerful reagent and provide an overview about novel reactions and uses of Lawesson's reagent.…”

Section: Introductionmentioning

confidence: 99%