PdCl<sub>2</sub>-Catalyzed Two-Component Cross-Coupling Cyclization of 2,3-Allenoic Acids with 2,3-Allenols. An Efficient Synthesis of 4-(1‘,3‘-Dien-2‘-yl)-2(5<i>H</i>)-furanone Derivatives
作者:Shengming Ma、Zhenhua Gu
DOI:10.1021/ja0500815
日期:2005.5.1
Cross-coupling cyclization reaction between 2,3-allenoic acids 1 and 2,3-allenols 2, in which two allenes functioned differently, was realized to afford 4-(1',3'-dien-2'-yl)-2(5H)-furanone derivatives3. The reaction may proceed via an oxypalladation, insertion, and beta-hydroxide elimination process. A high E-stereoselectivity of the new formed C=C double bond was observed.
Efficient Assembly of Chromone Skeleton from 2,3-Allenoic Acids and Benzynes
作者:Guobi Chai、Youai Qiu、Chunling Fu、Shengming Ma
DOI:10.1021/ol202076c
日期:2011.10.7
Chromone derivatives were synthesized from 2,3-allenoicacids and benzynes in moderate to excellent yields under mild conditions. Instead of the cyclic conjugate addition of the intermediate A formed by the nucleophilic addition of allenoic acid with benzyne, this intermediate undergoes 1,2-addition with the carbonyl group, which was followed by the ring opening, conjugate addition, and protonolysis
Palladium(II)-Catalyzed Highly Stereoselective Sandwich-Type Triple Cyclization Reaction of 1,5-Bisallenes and 2,3-Allenoic Acids
作者:Xiongdong Lian、Shengming Ma
DOI:10.1002/chem.201000992
日期:2010.7.19
Triple‐decker sandwich: A sandwich‐type triplecyclization of two molecules of 2,3‐allenoic acid and one molecule of 1,5‐bisallene in the presence of a palladium catalyst with excellent stereoselectivity has been developed. The diallyl‐substituted cis products may easily be transformed to fused tetracyclic compounds with a 12‐membered ring (see scheme). Based on the result of optically active 2,3‐allenoic
wherein n is an integer of 0 to 10; R
1
represents substituted or unsubstituted lower alkyl, substituted or unsubstituted lower alkoxy, substituted or unsubstituted cycloalkyl, substituted or unsubstituted lower alkoxycarbonyl, substituted or unsubstituted heterocyclic-alkyl, substituted or unsubstituted aryl, —CONR
7
R
8
, —NR
9
R
10
, etc.; R
2
represents substituted or unsubstituted aryl or a substituted or unsubstituted heterocyclic group, etc.; R
3
and R
5
may be the same or different, each represent a hydrogen atom, substituted or unsubstituted lower alkyl, etc.; R
4
and R
6
may be the same or different, each represent a hydrogen atom, halogen, substituted or unsubstituted lower alkyl, etc.)
Provided are an Hsp90 family protein inhibitor comprising, as an active ingredient, a benzene derivative of formula (I) or a prodrug thereof or a pharmaceutically-acceptable salt thereof, etc.
heterocyclic diazo compounds into allenic acids followed by base-promoted cyclization. Utilizing various diazo heterocycles, including α-diazo homophthalimides, 3-diazo tetramic acids, and diazo oxindoles, diverse spirocyclic scaffolds were produced. The research revealed that the allenic acid substitution pattern is decisive for the product type, enabling extraordinary target compound switching between