Hydroselenation of Alkynes by Lithium Butylselenolate:  An Approach in the Synthesis of Vinylic Selenides

Abstract

Vinylic selenides were prepared in good yields by hydroselenation of alkynes with lithium butylselenolate generated by reaction of n-butyllithium with elemental selenium. The regio- and stereochemistry of the hydroselenation depend on the nature of the substituents bonded to the alkyne.

Unusual Influence of the Structures of Transition Metal Complexes on Catalytic C–S and C–Se Bond Formation Under Homogeneous and Heterogeneous Conditions

“…(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) so far been developed, including halogen substitution in vinyl halides, [5] preparation from olefins [6] and carbonyl [7] compounds, rearrangement of propargylic aryl chalcogenides, [8] selenodecarboxylation, [9] utilization of In, [10] Al, [11] Li, [12] Ti, [13] and Ga [14] reagents, and some other methods. [1] The best solution to the problem would be provided by addition reactions of element-hydrogen (E-H) and elementelement (E-E) bonds to easily available acetylenic hydrocarbons (E = S, Se).…”

NaBH4/[bmim]BF4: a new reducing system to access vinyl selenides and tellurides

“…This regioselectivity is similar to that reported for the methods which use organic solvents. 1,[13][14][15][16][17][18][19][20] When the same protocol was applied to phenyl acetylene 1g, (E)-1,2-bis-phenylseleno styrene 5a was obtained in 85% yield after 3 h at 60 °C (Table 1, entry 7). This result is similar to that obtained under solvent-free conditions.…”

“…11,12 In this way, various methods are mentioned for the preparation of vinyl chalcogenides and the most common protocols involve the addition of organo chalcogenol, or the respective chalcogenolate anions, to terminal or internal alkynes. [1][2][3][4][5][6][7][8][9][10][13][14][15][16][17][18][19][20] On the other hand, ionic liquids (ILs) are receiving much attention in organic synthesis, both as recyclable solvents and/or catalysts. [21][22][23][24][25][26][27][28][29][30][31][32] Because product isolation or catalyst recycling is very easy in ILs and, in some cases, rate accelerations and/or selectivity improvements are also observed, they are regarded as environmentally friendly green solvents.…”

4.05 Addition of HX Reagents to Alkenes, Alkynes, and Allenes without Transition Metal

“…179 The nature of the substituents (steric and electronic effects) on the triple bond played an important role in controlling the regio-and stereoselectivity. …”