CARBON CARBON BOND-FORMING REACTIONS USING CERIUM METAL OR ORGANOCERIUM(III) REAGENTS
CARBON CARBON BOND-FORMING REACTIONS USING CERIUM METAL OR ORGANOCERIUM(III) REAGENTS
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DOI：
10.1021/jo00195a006
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发表时间：
1984-01-01
影响因子：
3.6
通讯作者：
YOKOYAMA, M
中科院分区：
文献类型：
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作者：
IMAMOTO, T;KUSUMOTO, T;YOKOYAMA, M
已经研究了使用铈金属或有机铈（III）试剂的碳-碳键形成反应。铈汞齐是从烯丙基卤和羰基化合物化学选择性合成高烯丙醇的有效试剂。同样的试剂也可以令人满意地用于卤代酯与羰基化合物的Reformatsky型反应。已经表明，有机铈（III）试剂通过有机锂与碘化铈（III）或氯化铈（III）的反应方便地产生。这些试剂的碱性低于有机锂和格氏试剂，它们在-78至-65 ℃下与各种羰基化合物进行干净的反应，以提供高产率的加成产物，即使底物易于烯醇化或与简单的有机锂进行金属-卤素交换。同样的试剂也可与α-不饱和羰基化合物反应，高选择性地生成1，2-加成产物.
Carbon-carbon bond-forming reactions using cerium metal or organocerium (III) reagents have been investigated. Cerium amalgam is an effective reagent for the chemoselective preparation of homoallylic alcohols from allyl halides and carbonyl compounds. The same reagent can also be satisfactorily employed for the Reformatsky-type reaction of-halo esters with carbonyl compounds. It has been shown that organocerium (III) reagents are conveniently generated by the reaction of organolithiums with cerium (III) iodide or cerium (III) chloride. The reagents are less basic than organolithiumsand Grignard reagents, and they react cleanly at-78 to-65 C with various carbonyl compounds to afford the addition productsin high yields, even though the substrates are susceptible to enolization or metal-halogen exchange with simple organolithiums. The same reagents react also with, ß-unsaturated carbonyl compoundsto yield 1, 2-addition products in high selectivity.