Department of Biomolecular Engineering, Tokyo Institute of Technology, Nagatsuta-cho 4259, Midori-ku, Yokohama, 226-8501, Japan.
Organization for the Strategic Coordination of Research and Intellectual Properties, Meiji University, 1-1-1, Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
Chemistry. 2021 Feb 19;27(11):3779-3785. doi: 10.1002/chem.202004413. Epub 2021 Jan 19.
The regioselectivity (r.s.) and enantiospecificity (e.s.) of the substitution reactions of secondary propargylic alcohol derivatives using reagents derived from ArMgBr and Cu salts were studied. First, the picolinate, 3-methylpicolinate, and diethylphosphonate derivatives of Ph(CH ) CH(OH)C≡CTMS were reacted with PhMgBr/CuCN in ratios of 2.5:2.7-2.5:0.25. The use of 2.5:0.25 ratio in THF/DME (6:1) at 0 °C for 1 h afforded the α-substitution product from the phosphate with ≥98 % r.s. and 99 % e.s. CuBr⋅Me S gave similar selectivity. The reaction system was then applied to phosphates derived from R CH(OH)C≡CR and ArMgBr to obtain synthetically sufficient r.s. and e.s. values with R =TMS, Ph, whereas iPr was borderline in terms of size as an R substituent. The presence of a substituent at the o-position of Ar marginally affected the selectivity. We also found that the use of PhMgBr/Cu(acac) in a 2:1 ratio in THF produced the γ-substitution products (allenes) with high r.s. and e.s.
使用源自 ArMgBr 和 Cu 盐的试剂，研究了仲丙炔醇衍生物的取代反应的区域选择性（r.s.）和对映选择性（e.s.）。首先，Ph(CH )CH(OH)C≡CTMS 的邻苯二甲酸盐、3-甲基邻苯二甲酸盐和二乙基膦酸盐与 PhMgBr/CuCN 以 2.5:2.7-2.5:0.25 的比例反应。在 0°C 下，在 THF/DME（6:1）中使用 2.5:0.25 的比例反应 1 小时，从磷酸盐中得到α取代产物，具有≥98%的 r.s.和 99%的 e.s.。CuBr⋅Me S 也给出了类似的选择性。然后，将该反应体系应用于 RCH(OH)C≡CR 和 ArMgBr 衍生的磷酸盐中，以获得具有足够合成选择性的 r.s.和 e.s.值，其中 R = TMS、Ph，而 iPr 作为 R 取代基在尺寸方面处于边缘状态。Ar 的邻位取代基的存在略微影响了选择性。我们还发现，在 THF 中使用 PhMgBr/Cu(acac)以 2:1 的比例生成具有高 r.s.和 e.s.的γ取代产物（丙二烯）。
