Asymmetric Synthesis of Benzoin by SmI2-Mediated Enantioselective Protonation
Asymmetric Synthesis of Benzoin by SmI2-Mediated Enantioselective Protonation
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SmI2介导的对映选择性质子化不对称合成安息香
DOI：
10.1246/bcsj.65.2001
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发表时间：
1992
影响因子：
4
通讯作者：
Y. Ohgo
中科院分区：
文献类型：
--
作者：
S. Takeuchi;N. Miyoshi;K. Hirata;H. Hayashida;Y. Ohgo
Sm(Z)-1，2-二苯基-1，2-二氧二酸酯被认为是SmI_2介导的苯并还原反应的中间体，在91%ee中被奎尼丁对映体选择性地质子化得到(R)-安息香。研究发现，未反应的沸石用氧气猝灭是获得高对映体选择性的关键。通过分离得到(Z)-O，O‘-二乙酰-1，2-二苯基-1，2-二醇，确定了化合物的构型。
Samarium (Z)-1,2-diphenylethen-1,2-diolate, which is considered to be an intermediate of a SmI2-mediated reduction of benzil, was protonated enantioselectively by quinidine to afford (R)-benzoin in 91%ee. It was found that quenching the unreacted enediolate with oxygen was crucial to obtain high enantioselectivity. The configuration of the samarium enediolate was confirmed by isolating (Z)-O,O′-diacetyl-1,2-diphenylethen-1,2-diol.