A Brønsted Acid Catalyzed Cascade Reaction for the Conversion of Indoles to α‐(3‐Indolyl) Ketones by Using 2‐Benzyloxy Aldehydes
作者:Ankush Banerjee、Modhu Sudan Maji
DOI:10.1002/chem.201902268
日期:2019.9.2
A Brønstedacid catalyzed, operationally simple, scalable route to several functionalized α-(3-indolyl) ketones has been developed and the long-standing regioisomeric issue has been eliminated by choosing appropriate carbonyls. A readily available and cheap bottle reagent was used as the catalyst. This protocol was also applicable to the synthesis of densely functionalized α-(3-pyrrolyl) ketones. A
Synthetic studies of didemnins. IV. Synthesis of the macrocycle
作者:William R. Ewing、Bruce D. Harris、Wen-Ren Li、Madeleine M. Joullie
DOI:10.1016/s0040-4039(01)80647-x
日期:1989.1
A stereocontrolled route to the 23-membered macrocycle found in the didemnins is described.
描述了在双氢精蛋白中发现的到23元大环的立体控制途径。
Total synthesis and structural investigations of didemnins A, B, and C
作者:Wen Ren Li、William R. Ewing、Bruce D. Harris、Madeleine M. Joullie
DOI:10.1021/ja00177a030
日期:1990.10
Didemnins A, B, and C were efficiently prepared in a stereocontrolled manner, producing the common macrocycle and, in a separate step, introducing the substituents on the amino group of L-threonine as optically pure units. We envisaged that disconnections between L-leucine and the HIP group (2S,4S) and between L-threonine and isostatine (3S,4R,5S) would afford two units: a HIP-isostatine unit (I) and
Didemnins A、B 和 C 以立体控制的方式有效制备,产生常见的大环,并在单独的步骤中,在 L-苏氨酸的氨基上引入取代基作为光学纯单元。我们设想 L-亮氨酸和 HIP 基团 (2S,4S) 之间以及 L-苏氨酸和异司他汀 (3S,4R,5S) 之间的断开将提供两个单元:HIP-异司他汀单元 (I) 和四肽单元 (II) )
Unique Stereocontrol in Europium(III)-Catalyzed Cyanosilylation of Chiral α-Alkoxy and α-Amino Aldehydes
The Eu(III)-catalyzed cyanosilylations of chiral α-alkoxy and α-amino aldehydes are shown to exhibit syn diastereofacial selection, the degree increasing with an increase in steric bulk of the alkyl chain in the aldehydes. The mechanism of this catalytic process is discussed.
Phosphine-Catalyzed Diastereoselective Synthesis of β-Lactones from Disubstituted Ketenes and α-Chiral Oxyaldehydes
作者:Mukulesh Mondal、Shi Chen、Nabil Othman、Kraig A. Wheeler、Nessan J. Kerrigan
DOI:10.1021/acs.joc.5b00869
日期:2015.6.5
In this article we describe a catalytic procedure for the diastereoselective synthesis of β-lactones bearing two stereogenic centers, from disubstituted ketenes and α-chiral oxyaldehydes. Tri-n-butylphosphine was found to be the optimal catalyst in terms of effecting both good yield and diastereoselectivity (dr from 3:1 to 32:1 for 8 examples) in β-lactone formation. The major isomer of the β-lactone
在本文中,我们描述了一种催化方法,用于从双取代的烯酮和α-手性乙醛中非立体选择性合成带有两个立体生成中心的β-内酯。三Ñ丁基膦被发现是在(3 DR 1 8实施例:1〜32)都实现良好的收率非对映选择性和方面的最佳催化剂在β内酯的形成。在β内酯产品的主要异构体被确定为是反非对映体,它的形成是由极性Felkin-映模型合理化。通过31 P NMR光谱的反应监测表明了烯醇盐中间体参与反应机理。(+)-peloruside A合成子的短合成证明了该方法的实用性。