Iridium Complex-Catalyzed Reaction of 1,6-Enynes: Cycloaddition and Cycloisomerization
摘要:
1,6-Enynes reacted with monoynes to give cyclohexadiene derivatives in the presence of a catalytic amount of (Ir(cod)CI](2)/ligand. DPPE was most suitable for cycloaddition. Diastereoselective cycloaddition was also possible. In the absence of monoynes, 1,6-enynes cycloisomerized to (2)-1-alkylidene-2-methylenecyclopentane derivatives. DPPF was most suitable for cyclolsomerization. These results are the first examples of highly Z-selective cycloisomerization.
A rhodium carbonyl complex, [RhCl(CO)(2)](2), serves as a catalyst of the intra- and inter-molecular Pauson-Khand reaction. By the use of the rhodium catalyst, cyclopentenone derivatives are prepared from various 1,6- and 1,7-enynes under 1 arm of CO. Furthermore, this rhodium-catalyzed reaction is accelerated by reducing partial pressure of CO to less than 1 atm. (C) 2001 Elsevier Science B.V. All rights reserved.
Stereoselective Nickel-Catalyzed [2+2+2] Cycloaddition of Enynes and Arynes
作者:Mark Lautens、David Candito
DOI:10.1055/s-0030-1261171
日期:2011.9
Examples of stereoselective reactions of aryne intermediates are rare in the literature. A stereoselectivenickel-catalyzed [2+2+2] cycloaddition of 1,6-enynes with aryne intermediates is reported. Excellent stereoselectivities were observed when a substituent is adjacent to the olefin moiety resulting in trans- stereochemistry in the products. This reaction is capable of generating much complexity
with a proximal alkoxy group is reported. This reaction, in the presence of a [Rh(cycloocta‐1,5‐diene)Cl]2/propane‐1,3‐diylbis(diphenylphosphane) system under a CO atmosphere, constitutes a powerful tool for selectively accessing carbo‐ and heterobicyclo[5.3.0] frameworks featuring an enol ether moiety. Through this procedure, a straightforward access to guaiane skeletons with a tertiary hydroxy group
A rhodium dinuclear carbonyl complex, [RhCl(CO)2]2, serves as a catalyst of the intramolecularPauson-Khandreaction. 1,6-Enynes are converted to cyclopentenone derivatives in high yield by heating in the presence of the catalyst under an atmospheric pressure of CO.
铑双核羰基络合物 [RhCl(CO)2]2 可作为分子内 Pauson-Khand 反应的催化剂。1,6-烯炔通过在催化剂的存在下在大气压的 CO 下加热以高产率转化为环戊烯酮衍生物。
Skeletal Reorganization of Enynes Catalyzed by InCl<sub>3</sub>
作者:Yuhei Miyanohana、Naoto Chatani
DOI:10.1021/ol060606d
日期:2006.5.1
[reaction: see text] The skeletalreorganization of enynes is achieved by the presence of InCl(3) as the catalyst. The reaction of enynes having a terminal acetylenic moiety proceeds in a stereospecific manner to give 1-vinylcycloalkenes. The reaction of enynes containing an alkyl group on the acetylenic terminal carbon resulted in a new type of skeletalreorganization to give 1-allylcycloalkenes,
we report room temperature, atom-economic protocols for high regio- and enantioselective tandem cycloisomerization–hydroarylation and cycloisomerization–hydroalkenylation of 1,6-enynes leading to vicinal carba-functionalized pyrrolidines, tetrahydrofurans, and cyclopentanes. The latter steps in these processes involve carbonyl-coordination-assisted ortho-C–H activation of aromatic aldehydes and esters
在此,我们报告了1,6-烯炔的高区域和对映选择性串联环异构化-加氢芳基化和环异构化-加氢烯基化的室温原子经济方案,产生邻位碳官能化的吡咯烷、四氢呋喃和环戊烷。这些过程的后面步骤涉及芳香醛和酯的羰基配位辅助的邻位C-H 活化,以及丙烯酸酯中类似但很少见的 β-C-H 活化。此类反应的合成有用的对映选择性版本很少见,并且仅限于吲哚和吡咯的 C 2 –H 活化。 N-乙烯基邻苯二甲酰亚胺也观察到类似的反应,它也具有适合 C-H 活化的羰基。二苯并氧杂磷配体 (2 S ,2 S' ,3 S, 3 S' )-MeO-BIBOP 被独特地鉴定为对于实现具有挑战性的区域选择性和对映选择性至关重要。该方法可以在低催化剂负载量下以良好的产率和优异的对映选择性获得取代的五元碳环和杂环化合物。在苯甲酸甲酯和d 5 -苯甲酸甲酯的分子间竞争实验中观察到初级 KIE 为 3.5,这表明 C-H 裂解是该过程的转换限制步骤。