108592-87-6Relevant articles and documents
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).
