69519-95-5Relevant academic research and scientific papers
(TRIALKYLSTANNYL)COPPER(I) REAGENTS: PREPARATION AND REACTION WITH α,β-UNSATURATED CARBONYL SYSTEMS. PREPARATION OF β-TRIALKYLSTANNYL α,β-UNSATURATED KETONES
Piers, Edward,Morton, Howard E.,Chong, J. Michael
, p. 78 - 87 (2007/10/02)
Reaction of Me3SnLi with 1 equivalent of CuBr*Me2S, PhSCu, Me2(MeO)C-CC-Cu, or CuCN in tetrahydrofuran (THF) affords the (trimethylstannyl)copper(I) reagents Me3SnCu*Me2S (1) and Li (Y = PhS (2), Me2(MeO)C-CC (4), CN (5)), respectively.Similarly, treatment of a THF solution of Me3SnLi with 0.5 equivalent of CuBr*Me2S provides (Me3Sn)2CuLi (3), while reaction of n-Bu3SnLi with PhSCu (1 equivalent) gives Li (6).Reagents 2 and 6 readily transfer (in a conjugate sense) the R3Sn group to conjugated enones (e.g. 7-9) and structurally simple enoates (e.g. 10), but do not react with β,β-disubstituted α,β-unsaturated esters (e.g. 11-13).Reaction of reagent 2 with the enone 26 under normal conditions produces, in addition to the expected ketone 28, a significant amount of the double conjugate addition product 30.A similar result is obtained with ethyl propenoate (27).However, reaction of 26 and 27 with reagent 2 in the presence of acetic acid provides cleanly and efficiently the simple conjugate addition products 28 and 29, respectively.Reagent 1 does not react, or reacts very sluggishly, with α,β-unsaturated carbonyl compounds. β-Trialkylstannyl α,β-unsaturated ketones (e.g. 37-46) can be produced smoothly and efficiently by reaction of the corresponding β-iodo enones (e.g. 32-36) with reagents 2 (or 1) and 6.
