Tandem electrocyclic ring opening/radical cyclization: application to the total synthesis of cribrostatin 6
作者:Daniel Knueppel、Stephen F. Martin
DOI:10.1016/j.tet.2011.08.064
日期:2011.12
A concise total synthesis of cribrostatin 6 (1), an antimicrobial and antineoplastic agent, was accomplished using a tandem electrocyclic ring opening/radical cyclization sequence. Specifically, intermediate 4 underwent a 4π-electrocyclic ring opening, radical cyclization, and homolytic aromatic substitution sequence followed by an oxidation to afford the natural product 1 in one pot. Owing to the
A photochemical ring expansion of 6- to 8-membered nitrogen heterocycles by [1,3]-sigmatropic rearrangement
作者:Morgan A. Manning、Wei Sun、Mark E. Light、David C. Harrowven
DOI:10.1039/d1cc00393c
日期:——
route to azocines and benzoazocines from furopyridinones is described through a photochemically induced [1,3]-sigmatropic rearrangement. The method gives access to these 8-membered nitrogen heterocycles from dimethyl squarate in four stages and with excellent atom economy by sequencing thermal and photochemicalringexpansion steps under continuous flow.
Organoytterbium Ate Complexes Extend the Value of Cyclobutenediones as Isoprene Equivalents
作者:Emma Packard、David D. Pascoe、Jacques Maddaluno、Théo P. Gonçalves、David C. Harrowven
DOI:10.1002/anie.201307193
日期:2013.12.2
Changing course: While organolithium and Grignard reagents favor addition to C1 of A (R=Me), the corresponding organoytterbium reagents add to C2 (R=tBu). Computational studies provide insights into the nature of organoytterbium species and their reactivity, and a total synthesis of (−)‐mansonone B illustrates the utility of the method in terpenoid synthesis. Tf=trifluoromethanesulfonyl.
改变方向:虽然有机锂和格氏试剂有利于A (R=Me)的 C1 上的加成,但相应的有机镱试剂会加成到 C2 (R= t Bu) 上。计算研究提供了对有机镱物种的性质及其反应性的见解,(−)-mansonone B 的全合成说明了该方法在萜类化合物合成中的实用性。Tf=三氟甲磺酰基。
INHIBITORS OF CXCR2
申请人:CHEMOCENTRYX, INC.
公开号:US20170144996A1
公开(公告)日:2017-05-25
Compounds are provided as inhibitors of CXCR2, having the structure:
Four-Electron Electrocyclic Ring-Opening/Intermolecular [4+2] Cycloadditions of α-Hydroxycyclobutenones: Stereoselective Synthesis of Multiple Substituted δ-Lactams
作者:Peidong Song、Qing Li、Congcong Wang、Wenfa Wu、Xu Mao、Jiajia Wang、Xiangdong Hu
DOI:10.1002/adsc.201501152
日期:2016.4.14
four‐electron electrocyclic ring‐opening/intermolecular [4+2] cycloaddition of α‐hydroxycyclobutenones is reported. The reaction represents the first example for the intermolecular cycloaddition of the extensively studied enol‐ketene intermediate, and provides a new synthetic route to multiply substituted δ‐lactams in high stereoselectivity.