Bergman cyclization
Masamune-Bergman cyclization | |
---|---|
Named after | Satoru Masamune
Robert George Bergman |
Reaction type | Ring forming reaction |
Identifiers | |
Organic Chemistry Portal | bergman-cyclization |
RSC ontology ID | RXNO:0000240 |
The Masamune-Bergman cyclization or Masamune-Bergman reaction or Masamune-Bergman cycloaromatization is an organic reaction and more specifically a rearrangement reaction taking place when an enediyne is heated in presence of a suitable hydrogen donor (Scheme 1).[1][2] It is the most famous and well-studied member of the general class of cycloaromatization reactions.[3] It is named for Japanese-American chemist Satoru Masamune (b. 1928) and American chemist Robert G. Bergman (b. 1942). The reaction product is a derivative of benzene.
![Scheme 1. Bergman cyclization](http://upload.wikimedia.org/wikipedia/commons/thumb/9/93/Bergman_cyclization.svg/500px-Bergman_cyclization.svg.png)
The reaction proceeds by a thermal reaction or
When the enyne moiety is incorporated into a 10-membered hydrocarbon ring (e.g. cyclodeca-3-ene-1,5-diyne in scheme 2) the reaction, taking advantage of increased ring strain in the reactant, is possible at the much lower temperature of 37 °C.
![Scheme 2. Bergman reaction of cyclodeca-3-ene-1,5-diyne](http://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/Bergman_ring.png/450px-Bergman_ring.png)
Naturally occurring compounds such as
A
![Bergman cyclization with capture by lithium bromide](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Bergman_cyclization_nuclSubst.png/500px-Bergman_cyclization_nuclSubst.png)
The reaction is found to be
![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a3/Bergman_cyclization_IBM2.png/330px-Bergman_cyclization_IBM2.png)
In 2015 IBM scientists demonstrated that a reversible Masamune-Bergman cyclisation of diyne can be induced by a tip of an
References
- .
- .
- PMID 23600723.
- .
- .
- PMID 17378569.
- ^ Borman, Stu (April 2, 2007). "New Route For Halide Addition". Chemical & Engineering News. Retrieved December 30, 2021.
- S2CID 21611919.
- ^ Sciacca, Chris (25 January 2016). "30 Years of Atomic Force Microscopy: IBM Scientists Trigger and Observe Reactions in an Individual Molecule". IBM Research News. IBM. Retrieved 25 January 2016.
External links
![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- Bergman Cycloaromatization Powerpoint Whitney M. Erwin 2002