Diastereoselective photocycloaddition reactions of 2-naphthalenecarboxylates and 2,3-naphthalenedicarboxylates with furans governed by chiral auxiliaries and hydrogen bonding interactions
作者:Hajime Maeda、Norihiro Koshio、Yuko Tachibana、Kazuhiko Chiyonobu、Gen-ichi Konishi、Kazuhiko Mizuno
DOI:10.1016/j.jphotochem.2017.08.052
日期:2017.12
By using chiral auxiliaries and hydrogen bonding interactions, we have developed diastereoselective photocycloaddition of 2-naphthalenecarboxylates and 2,3-naphthalenedicarboxylates with furan derivatives. In photoreactions of (ℓ)-menthyl 2-naphthalenecarboxylate with furan and 3-furanmethanol, respective maximum 48% and 40% diastereomeric excesses (d.e.) are observed. In photoreactions of di-8-phenyl-(ℓ)-menthyl
通过使用手性助剂和氢键相互作用,我们开发了呋喃衍生物2-萘羧酸盐和2,3-萘二羧酸盐的非对映选择性光环加成反应。在(光反应的ℓ) -薄荷基-2-萘羧酸与呋喃和3-呋喃甲醇,各自的最大48%和40%非对映体过量的(de)中观察到。在di-8-phenyl-(ℓ的光反应中用3-呋喃甲醇制得2,3-萘二甲酸薄荷基-薄荷酯,最大67%de。使用低极性,低温和低呋喃浓度的溶剂会导致非对映选择性增加。可变温度(VT)NMR和荧光猝灭研究表明,萘羧酸酯的羰基氧与3-呋喃甲醇中的OH基团之间的氢键相互作用在基态和激发态下均发生。计算研究的结果表明,C 2对称萘二羧酸酯反应物的几何形状对于控制2,3-萘二羧酸酯的光反应中的高非对映选择性很重要。