Synthesis of 3,4-Disubstituted 2H-Benzopyrans through C−C Bond Formation via Electrophilic Cyclization
摘要:
[GRAPHIC]The electrophilic cyclization of substituted propargylic aryl ethers by I-2, ICl, and PhSeBr produces 3,4-disubstituted 2H-benzopyrans in excellent yields. This methodology results in vinylic halides or selenides under mild reaction conditions and tolerates a variety of functional groups, including methoxy, alcohol, aldehyde, and nitro groups.
Nanohoop Rotaxanes from Active Metal Template Syntheses and Their Potential in Sensing Applications
作者:Jeff M. Van Raden、Brittany M. White、Lev N. Zakharov、Ramesh Jasti
DOI:10.1002/anie.201901984
日期:2019.5.27
systems render them fascinating candidates for the design of novel mechanically interlocked molecules with new properties. Two high‐yielding strategies are used to prepare nanohoop [2]rotaxanes, which owing to the π‐rich macrocycle are highly emissive. Then, metal coordination, an intrinsic property afforded by the resulting mechanical bond, can lead to molecular shuttling as well as modulate the observed
NANOHOOP COMPOUND EMBODIMENTS COMPRISING META-SUBSTITUTION AND MOLECULAR SYSTEMS COMPRISING THE SAME
申请人:Jasti Ramesh
公开号:US20200010419A1
公开(公告)日:2020-01-09
Disclosed herein are embodiments of nanohoop compounds, methods of making, and methods of using the same. The nanohoop compounds disclosed herein have discrete ring system(s) that comprise a unique meta-substituted motif that affords a strained cavity in which myriad reaction chemistries can take place. The unique structures and properties of the nanohoop compounds disclosed herein also lend to their use in a variety of biological applications, and as interlocked structures in molecular machines.
Molecular information ratchets are key to the construction of autonomous, chemically fueled small-molecule motors. We have developed a novel type of information ratchet sensitive to two types of information: the position and the orientation of a moving macrocycle on an axle. The originality of this system comes from the use of a cone-shaped chiral macrocycle, a cyclodextrin, that presents two distinct
A chiral macrocycle for the stereoselective synthesis of mechanically planar chiral rotaxanes and catenanes
作者:Shu Zhang、Arnau Rodríguez-Rubio、Abed Saady、Graham J. Tizzard、Stephen M. Goldup
DOI:10.1016/j.chempr.2023.01.009
日期:2023.2
pre-macrocycle components (catenanes), and thus mechanically chiral rotaxane and catenane syntheses rely on different chiral components. Here, we present a single, simple amino-acid-derived macrocycle that mediates the formation of both catenanes and rotaxanes in excellent stereoselectivity. We demonstrate the flexibility of our approach through the stereoselective synthesis of all three isomers of a co-conformationally