Dobromir D. Enchev

1,2-ALKADIENEPHOSPHONIC AMIDOESTERS AND THEIR OXAPHOSPHOLIC CYCLIZATION IN REACTION WITH ELECTROPHILIC REAGENTS

Abstract By the reaction of 1,2-alkadienephosphonic dichlorides with dialkylamines and aliphatic alcohols, the 1,2-alkadienephosphonic amidoesters 2a-k have been prepared. The synthesized 1,2-alkadienephosphonates 2a-k have been cyclized in reactions with different electrophiles. The obtained 2,5-dihydro-1,2-oxaphosphole derivatives are characterized by spectral data and elemental analyses.

HETEROCYCLIZATION OF 1,2,4- AND 1,3,4-ALKATRIENYLPHOSPHONIC DICHLORIDES WITH ELECTROPHILIC REAGENTS

Abstract By the reaction of 1,2,4- and 1,3,4-alkatrienylphosphonic dichlorides with sulfuryl, sulfenyl and selenenyl chlorides, the different P-containing heterocyclic compounds have been prepared. The obtained heterocycles contained one or two chorine atoms at phosphorus which have great reactivity and can change with another functional groups.

HETEROCYCLIC PHOSPHONIUM SALTS BY REACTION OF DIMETHYL(1,2-ALKADIENYL)-PHOSPHINE OXIDES WITH ELECTROPHILIC REAGENTS

Abstract Salts of 2,5-dihydro-1,2-oxaphosphole have been prepared by reaction of dimethyl(1,2-alkadienyl)phosphine oxides with halogens, sulfenyl and selenenyl chlorides. The essential influence of tertiary carbenium ions for realization of oxaphospholic cyclization of phosphorylated allenes has been established.

1,4-CYCLOADDITION REACTION OF SULFUR DIOXIDE TO DIALKYL(3-METHYL-1,2,4-PENTATRIENYL)PHOSPHONATES

Abstract Phosphorylated 2,5-dihydrothiophene-l,1-dioxides are obtained by 1,4-cycloaddition reaction of sulfur dioxide to dialkyl(3-methyl-1,2,4-pentatrienyl)phosphonates. The structure of the products was established by analyses of the ir and 1H-nmr spectra.

1,2-Alkatrienephosphonates in the Reactions with Sulfenyl- and Selenenylbromides

The interaction of 1,2-alkatrienephosphonic dichlorides and dialkyl esters with sulfenyl- and selenenylbromides is investigated and a possible mechanism of the reactions is discussed. The possibility to control the structure of the products by variation of the type of the electrophile and of the substrate is also shown.

Allene-Substituted-1,3,2-Dioxaphospholanes in the Reactions with Sulfenyl Bromides and Selenenyl Bromides

The reactivity of allene-substituted-1,3,2-dioxaphospholanes towards sulfenyl bromides and selenenyl bromides has been investigated, and 2,5-dihydro-1,2-oxaphosphole derivatives have been obtained.

New Derivatives of 1,2-Alkadienephosphonic Acids

Abstract The preparations of new cyclic derivatives of 1,2-alkadienephosphonic acids have been reported and the reactions of these compounds with bromine have been investigated.

New Phosphorus Derivatives of Salicylic Acid

Abstract The chemistry of phosphorus derivatives of salicylic acid has been revived and the synthesis of alkadienephosphonate derivatives of salicylic acid is reported.

2,5-Dihydro-1,2-oxaphosphole Derivatives in the Reaction of 3,3-Disubstituted Allenylphosphonic Amidoesters with Electrophilic Reagents

Abstract The reaction of 3,3-disubstituted allenylphosphonic amidoesters with halogenes, sulfenyl and selenenylchlorides proceeds with five-membered heterocyclization and formation of 2-N,N-dialkylamino-2,5-dihydro-1,2-oxaphosphole 2-oxides: