42226-36-8Relevant academic research and scientific papers
Improved Synthesis of Asymmetrical Substituted 1 H-1,2,4-Diazaphospholes
Liu, Qiaoyun,Wu, Jing,Li, Junfei,Wang, Junwen,Zheng, Wenjun,Roesky, Herbert W.
supporting information, p. 1455 - 1466 (2015/10/29)
The reaction of tris(trimethylsilyl)phosphine and a mixture of two different N,N-dimethylalkylamides (1a,b), followed by the treatment with dry hydrazine in situ, resulted in seven asymmetrical 3,5-disubstituted 1H-1,2,4-diazaphospholes (3a-g). Compounds
Ungewoehnlich koordinierte Phosphorverbindungen XXIV. Methylidinphosphan (HCP), ein neuer Cycloadditionspartner fuer 1,3-Dipole
Fuchs, E. P. O.,Hermesdorf, M.,Schnurr, W.,Roesch, W.,Heydt, H.,Regitz, M.
, p. 329 - 340 (2007/10/02)
Methylidynephosphane (2) is generated under flash pyrolytic conditions by cleavage of isobutene from the phosphaalkyne (1) or by elimination of hydrogen chloride from dichloromethylphosphine (3).It undergoes -cycloaddition reactions with stable dipoles eq. diazo compounds (2+4a,b->5a,b), methyl azide (2+7->8), benzonitriloxide (2+10->12, 1:2-adduct) and 3-methyl-2,4-diphenyl-1,3-oxazolium-5-olate (2+13->15) to give the corresponding phospholes.Silylated phosphaalkene (19) can be used as a synthetic substitute for 2: the 5-trimethylsilyl-1H-1,2,4-diazaphospholes (22), which result from the reaction of 19 and the diazo compound 4 with chlorotrimethylsilane elimination, are desilylated to 5 by potassium fluoride in dimethyl formamide.
Phosphorus Compounds with Unusual Coordination, 31. Cycloaddition of Diazo Compounds onto a P - Chloro-phosphaalkene
Schnurr, Werner,Regitz, Manfred
, p. 1285 - 1292 (2007/10/02)
Chloro bis(trimethylsilyl)methylene phosphane (4) reacts with the diazo compounds 5, 10, 15 and 20 even at low temperatures with formation of the 3H-1,2,4-diazaphospholes 6, 11, 16 and 21.The products are unstable and decompose either with elimination of nitrogen to yield 1-chlorophosphiranes (9, 14, 19 and 22), or isomerize with aromatization (11-->13) or transformation into 4,5-dihydro-1,2,4-diazaphospholes (6-->8, 16-->18) by trimethylsilyl shifts.Silyl groups attached to ring nitrogen are easily hydrolized (8-->7, 13-->12, 18-->17), those attached to ring carbon are cleaved by treatment with potassium fluoride in dimethyl formamide (7-->23, 12-->24). - Keywords: Chloro-methylene Phosphanes, Diazo Compounds, 1,2,4-Diazaphospholes, 1-Chlorophosphiranes
Phosphorus Compounds with Unusual Coordination, 19. - 1,2,4-Diazaphospholes by Cycloaddition of Diazo Compounds onto a Stable Phosphaalkyne
Roesch, Wolfgang,Hees, Udo,Regitz, Manfred
, p. 1645 - 1652 (2007/10/02)
Diazomethyl compounds (2a-h) add regiospecifically onto the phosphaalkyne 1 to the adducts 3 which isomerize by spontaneous H-shift to the 1,2,4-diazaphospholes 4a-h.Onty at the reaction 2i+1 the H-shift is suppressed in favour of a trimethylsilyl migration (->6i).Also at the addition of α-diazo ketones 7a-e onto 1 the primary adducts 8 cannot be isolated as they isomerize by fast acyl-shift to N-acceptor-substituted diazaphospholes (9a-e).In the case of 7a-c parallel to that formation of isomers (11a-c) can be demonstrated.The corresponding reaction sequence of the phosphaalkyne 1 with cyclic α-diazo ketones (12, 14, 16, 18) makes easily accessible annelated representatives of the same structural type (13, 15, 17, 19).Phosphoryl group migrations are responsible for the formation of phosphorylated 1,2,4-diazaphospholes (24-c) at the reaction 1+20a-c.N-Acyl and -phosphoryl groups of the rearranged cycloadducts are easily solvolysed (9a-e -> 4b,c,j,k; 24a-c -> 4b,c; 13 -> 25).
