Conjugated Addition of Organocopper Reagents to the Enone Group Adjacent to a CpMo(CO)2(.pi.-allyl) Fragment
Conjugated Addition of Organocopper Reagents to the Enone Group Adjacent to a CpMo(CO)2(.pi.-allyl) Fragment
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有机铜试剂与 CpMo(CO)2(.pi.-烯丙基) 片段相邻的烯酮基团的共轭加成
DOI：
10.1021/om00017a031
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发表时间：
1994
期刊：
影响因子：
2.8
通讯作者：
Rai‐Shung Liu
中科院分区：
文献类型：
--
作者：
Shie;S. Lush;Wie;Gene;S. Peng;Yuan;Sue‐Lein Wang;Rai‐Shung Liu
1，4-有机铜试剂与CpMo(CO)_2(77*123-L-反式-COCH=氯烯丙基)(R=Ph(1)，2-呋喃(2)，甲基(3))以合理的非对映选择性进行加成，在BF_3-Et_(20)等摩尔比存在下可提高到很好的水平。通过X-射线结构分析确定了主要非对映异构体的立体化学结构，表明溶液中1-3的少量物种--S-反式烯酮构象是活性物种。这些主要产物的顺烯醇类化合物都是由具有良好的非对映选择性的LiN(SiMe3)2选择性地与醛缩合生成的，并测定了代表性产物的X-射线结构。进一步展示了这些羟醛产物在立体选择性合成2，3，4，5-四氢呋喃中的应用。
1, 4-Addition of organocopperreagents to CpMo (CO) 2 (77* 123-l-trans-COCH= CHR-allyl)(R= Ph (1), 2-furyl (2), methyl (3)) proceeded in reasonable diastereoselectivities that can be improved to excellent levels in the presence of BF3-Et20 at one equimolar proportion. The stereochemistry of the major diastereomeric products was elucidated from X-ray structural analysis, which indicated that the minor species of 1-3 in solution, the s-trans-enone conformer, is the active species. The cis-enolates of these major products were selectively generated by LiN (SiMe3) 2 which condensed with aldehydes in excellent diastereoselectivities, and X-ray structures of representative products were determined. Further utilization of these aldol products for stereoselective synthesis of 2, 3, 4, 5-tetrahydrofurans is demonstrated.