Synthesis of Alkynyl‐Glycinols by Lewis Acid Catalyzed Propargylic Substitution of Bis‐Imidates
Synthesis of Alkynyl‐Glycinols by Lewis Acid Catalyzed Propargylic Substitution of Bis‐Imidates
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路易斯酸催化双亚胺酯的炔丙取代合成炔基甘氨醇
DOI：
10.1002/ejoc.201500937
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发表时间：
2015
影响因子：
2.8
通讯作者：
A. Jirgensons
中科院分区：
文献类型：
--
作者：
Jekaterina Sirotkina;L. Grigorjeva;A. Jirgensons
由炔基二醇衍生的双三氯乙酰亚胺酯经刘易斯酸催化环合反应可合成外消旋和对映体富集的炔基甘氨酸醇。环化反应选择性地进行，得到作为炔丙基取代产物的4-炔基恶唑啉。在乙炔上含有烷基或三甲基甲硅烷基取代基的对映体富集的双亚胺得到构型完全反转的恶唑啉。反过来，在含有苯基取代基的双亚胺的环化中观察到相当大的外消旋化。通过在苯环上引入电负性取代基，可以抑制这些底物的外消旋作用。通过双亚胺酸酯环合反应制备的恶唑啉可以容易地转化为受保护的炔基乙二醇衍生物。
Racemic and enantioenriched alkynyl-glycinols can be synthesized by Lewis acid catalyzed cyclization reaction of bis-trichloracetimidates derived from alkynyl-glycols. The cyclization proceeds selectively to give 4-alkynyl-oxazolines as the propargylic substitution products. Enantioenriched bis-imidates that contain an alkyl or trimethylsilyl substituent at the acetylene gave oxazolines with complete inversion of configuration. In turn, considerable racemization was observed in the cyclization of bis-imidates that contain a phenyl substituent. The racemization for these substrates can be suppressed by introduction of the electronegative substituent at the phenyl ring. Oxazolines prepared by bis-imidate cyclization reaction can be readily transformed to protected alkynyl-glycol derivatives.
影响因子：
15
作者：
B. Trost;M. Rudd
通讯作者：
B. Trost;M. Rudd
影响因子：
15
作者：
Shu, Xing-Zhong;Li, Xiaoxun;Shu, Dongxu;Huang, Suyu;Schienebeck, Casi M.;Zhou, Xin;Robichaux, Patrick J.;Tang, Weiping
通讯作者：
Tang, Weiping