作者:Xuan Huang、Liqiang Song、Jiao Xu、Guili Zhu、Bo Liu
DOI:10.1002/anie.201208687
日期:2013.1.14
Less stable, but natural: The asymmetric totalsynthesis of leucosceptroidB (see scheme) has been accomplished in 19 steps. Thermodynamically, this natural product proved to be less stable than its C11 epimer, a synthetic intermediate. This synthesis features a high degree of flexibility, facilitating its application to the preparation of a broad range of other natural derivatives.
Diastereofacial Control in the Reaction of (R)-α-(<i>p</i>-Tolylsulfinyl)acetophenones with Several Organometallics
作者:Tamotsu Fujisawa、Atsushi Fujimura、Yutaka Ukaji
DOI:10.1246/cl.1988.1541
日期:1988.9.5
controlled addition of organometallics to optically active β-ketosulfoxide was achieved to furnish both diastereomers of β-hydroxy sulfoxide depending on the selection of organometallic reagents. Trichloromethyltitanium added to (R)-α-(p-tolylsulfinyl)acetophenones to give (RsRc)-β-hydroxy sulfoxides, while (RsSc)-β-hydroxy sulfoxides were obtained by utilizing trimethylaluminum. The utility of the present
Metalated Nitriles: S<sub>N</sub>i and S<sub>N</sub>i′ Installation of Contiguous Quaternary-Tertiary and Quaternary-Quaternary Centers
作者:Jesus A. Lujan-Montelongo、Ping Lu、Wang Liu、Fraser F. Fleming
DOI:10.1002/chem.201301046
日期:2013.7.1
“Black belt” SNi and SNi′: Deuterium labeling revealed an inherent preference of N‐ and C‐metalatednitriles for SNi, rather than SNi′ displacement. The fundamental reactivity preferences are harnessed in a series of cyclizations to cis‐ and trans‐decalins that install contiguousquaternary–tertiary and quaternary–quaternary stereocenters (see scheme).
“黑带” S N i 和 S N i':氘标记揭示了N-和C-金属化腈对 S N i的固有偏好,而不是 S N i' 置换。基本的反应性偏好在一系列环化中被利用到顺式和反式十氢化萘,这些环化安装连续的四元 - 三次和四元 - 四元立体中心(见方案)。
Skeletal and Stereochemical Diversification of Tricyclic Frameworks Inspired by Ca<sup>2+</sup>-ATPase Inhibitors, Artemisinin and Transtaganolide D
Inspired by the common skeletal motifs of Ca2+-ATPases inhibitors involving artemisinin and transtaganolide D, small molecule collections with the three-dimensional structural diversity of tricyclic systems were designed and expeditiously synthesized (4-5 steps). A synthetic strategy featuring stereochemical diversification of ring-junctions and control of cyclization modes was devised to access varied molecular architectures in a systematic fashion.
FUJISAWA, TAMOTSU;FUJIMURA, ATSUSHI;UKAJI, YUTAKA, CHEM. LETT.,(1988) N 9, C. 1541-1544