Palladium(0)-Catalyzed Cross-Coupling of 1,1-Diboronates with Vinyl Bromides and 1,1-Dibromoalkenes
作者:Huan Li、Zhikun Zhang、Xianghang Shangguan、Shan Huang、Jun Chen、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201407000
日期:2014.10.27
Palladium‐catalyzed cross‐coupling reactions of 1,1‐diboronates with vinylbromides and dibromoalkenes were found to afford 1,4‐dienes and allenes, respectively. These reactions utilize the high reactivities of both 1,1‐diboronates and allylboron intermediates generated in the initial coupling.
Amide-Directed Catalytic Asymmetric Hydroboration of Trisubstituted Alkenes
作者:Sean M. Smith、James M. Takacs
DOI:10.1021/ja908257x
日期:2010.2.17
rhodium-catalyzed reaction is stereospecific. In addition, simple TADDOL-derived phenyl monophosphite ligands in combination with Rh(nbd)(2)BF(4) afford highly enantioselective catalysts (seven examples, 91-98% ee). These catalysts provide an alternative methodology to prepare Felkin or anti-Felkin acetate-aldol products and related derivatives that are obtainable from the intermediate chiral organoboranes
Approach toward the total synthesis of orevactaene. Part 1: Assembly of the contiguous trisubstituted olefin component
作者:Michael G. Organ、Svetoslav Bratovanov
DOI:10.1016/s0040-4039(00)01189-8
日期:2000.9
An approach to the conjugated polyene chain component of orevactaene is reported. A modular approach has been devised to link the two stereocentre-containing ends of the structure together via a tri-substituted olefin-template. Key to the success of this approach is an efficient ‘one pot’ lithium/halogen exchange, boron/lithium exchange, borate ester saponification, and cross-coupling sequence to provide
Studies Towards a Concise Enantioselective Synthesis of Roseophilins
作者:Daniel J. Kerr、Bernard L. Flynn
DOI:10.1071/ch15407
日期:——
An oxazolidone auxiliary-controlled asymmetric Nazarov reaction has been applied to the synthesis of the cyclopentyl-fused pyrrole core of roseophilins. Additionally, a concise synthetic route to the pyrrole-furan biaryl fragment required in the synthesis of the recently isolated dechlororoseophilin is described. It is anticipated that these two syntheses can be combined in future efforts to provide
Synthesis Toward and Stereochemical Assignment of Clathsterol: Exploring Diverse Strategies to Polyoxygenated Sterols
作者:Tao Zhou、Feng Feng、Yong Shi、Wei-Sheng Tian
DOI:10.1021/acs.orglett.6b01029
日期:2016.5.6
Herein we describe a synthesis of the trisulfate derivative of clathsterol (1), a marine sterol endowed with impressive structural features and moderate inhibitory activity against HIV-1 reverse transcriptase. By synthesizing two possible isomers of the side chain, the stereochemistry of 1 is assigned. In creating chiral side chains from steroidal lactone, our strategies, including an addition/reduction
在这里,我们描述了笼固醇(1)的三硫酸盐衍生物的合成,该固醇是一种海洋甾醇,具有令人印象深刻的结构特征和对HIV-1逆转录酶的适度抑制活性。通过合成侧链的两个可能的异构体,分配了1的立体化学。从甾体内酯生成手性侧链时,我们的策略包括加成/还原生成C22 R –OH的步骤,环氧化物开放反应和[3.3]重排以诱导C24 S -Et和C24 R的生成-Et分别具有高度的灵活性和互补性。