A Regioselective Synthesis of Novel Functionalized Organochalcogen Compounds by Chalcogenocyclofunctionalization Reactions Based on Chalcogen Halides and Natural Products

Abstract

The regioselective synthesis of novel functionalized condensed organochalcogen compounds by chalcogenocyclofunctionalization reactions based on chalcogen halides and the natural products thymol and carvacrol has been developed. The reactions of selenium dibromide with allyl thymol and allyl carvacrol proceeded in methylene chloride at room temperature in the presence of NaHCO3 affording bis[(7-isopropyl-4-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] and bis[(4-isopropyl-7-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] selenides in 90–92% yield. Similar sulfides were obtained in 70–72% yields by the reaction of sulfur dichloride in chloroform under reflux. Trihalotellanes containing the same organic moieties were synthesized from allyl thymol, allyl carvacrol and tellurium tetrachloride or tetrabromide in quantitative yields. Corresponding functionalized ditellurides were prepared in 91–92% yields by the reduction of the trichlorotellanes with sodium metabisulfite in two-phase solvent system. The comparison of reactivity of sulfur, selenium and tellurium halides in chalcogenocyclofunctionalization and distinguishing features of each reaction were discussed.

Recent Advances in Design and Synthesis of 1,3-Thiaselenolane and 1,3-Thiaselenole Derivatives

“…The first synthesis of organose-lenium compounds from selenium dichloride and dibromide is the preparation of 1,4selenasilafulvenes by the cyclization reaction of these reagents with dimethyldiethynylsilane [52]. The selectivity and efficiency of the use of selenium dichloride and dibromide in organic synthesis have been shown in many reactions, which made it possible to obtain previously unknown classes of organoselenium compounds and study their chemical properties [53][54][55][56][57][58][59][60][61][62][63][64][65][66]. Compounds with high glutathione peroxidase-like activity have been found [56].…”

“…Using this approach, a one-pot synthesis of novel, functionalized organoselenium compounds by bis-alkoxyselenenylation of alkenes with selenium dibromide and alcohols has been developed [59]. An efficient regioselective synthesis of novel, functionalized organoselenium compounds by cyclofunctionalization reactions of selenium dihalides with natural compounds and their derivatives has also been realized [61].…”

“…The use of selenium dichloride and dibromide made it possible to discover new possibilities in organic synthesis [53][54][55][56][57][58][59][60][61][62][63][64][65][66]. The reaction of selenium dichloride with divinyl sulfide at −50 • C in chloroform gave six-membered heterocycle, 2,6-dichloro-1,4-thiaselenane (1) (a 6/1 diastereomer ratio), in quantitative yield, which underwent rearrangement (chloroform, room temperature) to a five-membered heterocycle, 5-chloro-2-chloromethyl-1,3thiaselenolane (2) in 61% yield (a 2/1 diastereomer ratio).…”

“…Triselenathiafulvalene (61) was synthesized as a result of the homo-coupling of 4,5dicarbomemethoxy-1,3-diselenole-2-thione 62 in the presence of triethyl phosphite and further decarbomethoxylation of compound 63 (yield 40%) (Scheme 20) [126]. This method is very promising because the initial semi-product 62 was obtained without the use of toxic carbon diselenide via intermediate titanocene pentaselenide 64 in 43% yield.…”

Transannular Selenocyclofunctionalization of 1,5-cyclooctadiene: The Antioxidant Properties of 9-selenabicyclo[3.3.1]nonane Derivatives and the Discovery of Increasing Both GPx and GR Activities

“…The use of these reagents opened up new possibilities for the synthesis of new classes of organoselenium compounds. Novel approaches, including transannular selenocyclization, annulation/selenofunctionalization, and selenobisfunctionalization, were developed [19][20][21][22][23][24][25][26][27].…”