The Reactivity of Epoxides with Lithium 2,2,6,6-Tetramethylpiperidide in Combination with Organolithiums or Grignard Reagents

Abstract

The scope and limitations of lithium 2,2,6,6-tetramethylpiperidide (LTMP)-modified reductive alkylation of epoxides is detailed. A variety of organolithiums are added to terminal and 2,2-disubstituted epoxides in the presence of LTMP to generate alkenes in a completely regio- and highly stereoselective manner. Arylated alkenes, dienes, allylsilanes, and enynes are accessed using this procedure. The methodology is applied in the synthesis of the roller leaf moth pheromone, (3E,5Z)-dodecadienyl acetate. The corresponding reaction without LTMP has also been examined, and a study using deuterated epoxides provides insight into the mechanism. In the presence of LTMP, Grignard reagents are also shown to produce E-alkenes directly from epoxides.

Small molecule probes of the receptor binding site in the Vibrio cholerae CAI-1 quorum sensing circuit

“…The spectral data for B5 is consistent with previously reported data for this compound. 18 1 H NMR (500 MHz, CDCl 3 ) δ 3.50 (m, 1H), 1.50 (m, 2H), 1.39 (m, 4H), 1.26 (m, 14H), 0.92 (t, J = 7.5 Hz, 3H), 0.86 (t, J = 6.9 Hz, 3H). 13 C NMR (125 MHz, CDCl 3 ) δ 73.6, 37.2, 32.1, 30.4, 29.94, 29.86, 29.84, 29.6, 25.9, 22.9, 14.4, 10.1.…”

Chromatography with silver nitrate: part 2

“…In 2007 Hodgson 58 developed a method to generate alkenes from epoxides and alkyl lithium reagents in the presence of lithium 2,2,6,6-tetramethylpiperidide (LTMP, 84). His group then applied this methodology to the synthesis of (3E,5Z)-dodecadienyl acetate 85, which is a pheromone of the roller leaf moth.…”

Reactivity of (Mono‐tert‐butyloxiranyl)lithium: A Theoretical Ab Initio Study

“…Elimination of Li 2 O from the primary adduct leads to the formation of an ethylene species. When bulky amides are used for addition to the alkyllithium, highly stereoselective reactions are observed 15. Finally, dimerisation of the carbene has also been observed16 and leads to the formation of diols.…”