First Isolable tert-Alkyl Phenyl Selones

Abstract

The reaction of the dihydrazone of 2,2,6,6-tetramethyl-1,7-diphenyl-1,7-dione with Se2Cl2 in refluxing benzene in the presence of tributylamine gave the corresponding 1-oxo-7-selone and 1,7-diselone derivatives in 14 and 33% yields, respectively, while similar reaction of the dihydrazone of 2,2,5,5-tetramethyl-1,6-diphenyl-1,6-dione gave bicyclic 1,3-diselenetane (25%), 1,2,4-triselenolane (20%), and cyclohexene (12%) derivatives by intramolecular cyclizations.

Synthesis and Physical Properties of Sterically Congested Cycloalkenes, 1,2-Di-tert-butyl-3,3,5,5-tetramethylcyclopentene and 1,2-Di-tert-butyl-3,3,6,6-tetramethylcyclohexene

“…We previously observed that the diphenyl analogue 29 reacted with Se 2 Cl 2 in the presence of ( n -Bu) 3 N to produce the cyclohexene 30 along with the bicyclic selenium compounds 31 and 32 . The 1,3,4-selenadiazoline 33 was proposed as the intermediate for 30 …”

First isolable dithiiranes: 3-(1,1,3,3-tetramethyl-4-oxo-4-phenylbutyl)-3-phenyldithiirane 1-oxides

“…On the other hand, the dithiirane oxide 4 decomposes on heating to give the thioketone 10 and 6 11 Ph& 12 Thermal isomerization of 4 to 5 was also observed; heating a solution of 4 in toluene-ds at 110 OC for 0.5 h gave a mixture of 4, 5, 10,6, and 7 in the ratio of 62:9:7:17:6. in a stereospecific manner.…”

Stannic chloride-induced unsymmetrical CSe bond cleavage of bis(N,N-dimethylcarbamoylseleno)methanes: Novel generation of selenoaldehydes

“…Interestingly, treatment of a chloroform solution of 1a with SnCl 4 at refluxing temperature afforded an epimeric mixture of 1,2,4-triselenolanes 8a (10%, approximately 1:1 mixture) [36][37][38][39] along with the formation of selenocarbamate 9a (25%), diselenide 4 (14%), and a trace amount of 6a. A similar reaction of a chloroform solution of 1e with SnCl 4 at refluxing temperature just gave a small amount of solvent-insoluble polymeric compound, characterizable to be polymethylene selenide (10e, approximately 20%) [40][41][42][43][44][45][46][47] by using IR spectrum, along with an unstable compound characterized by novel 1,2,4,5-tetraselenane (11e, approximately 4%).…”