Effect of Ring Functionalization on the Reaction Temperature of Benzocyclobutene Thermoset Polymers
作者:Colin O. Hayes、Peng-hao Chen、R. Paxton Thedford、Christopher J. Ellison、Guangbin Dong、C. Grant Willson
DOI:10.1021/acs.macromol.6b00316
日期:2016.5.24
The temperature required to induce cross-linking in typical benzocyclobutene-based thermosets is near 250 °C, which exceeds the use temperature of many chemical components. A new and versatile synthesis of BCB-functionalized monomers has allowed access to monomers that can be incorporated into a variety of macromolecular platforms to enable significantly reduced cure temperatures. Incorporation of
Enantioselective Rh-Catalyzed Carboacylation of C═N Bonds via C–C Activation of Benzocyclobutenones
作者:Lin Deng、Tao Xu、Hongbo Li、Guangbin Dong
DOI:10.1021/jacs.5b11120
日期:2016.1.13
Herein we describe the first enantioselective Rh catalyzed carboacylation of mimes (imines) via C-C activation. In this transformation, the benzocyclobutenone C1-C2 bond is selectively activated by a low valent rhodium catalyst and subsequently the resulting two Rh-C bonds add across a C=N bond, which provides a unique approach to access chiral lactams. A range of polycydic nitrogen-containing scaffolds were obtained in good yields with excellent enantioselectivity. Further derivatization of the lactam products led to a rapid entry to various novel fused heterocycles.
Concise synthesis of functionalized benzocyclobutenones
作者:P.-H. Chen、Nikolas A. Savage、Guangbin Dong
DOI:10.1016/j.tet.2014.03.080
日期:2014.7
to access functionalized benzocyclobutenones from 3-halophenol derivatives is described. This modified synthesis employs a [2+2] cycloaddition between benzynes generated from dehydrohalogenation of aryl halides using LiTMP and acetaldehyde enolate generated from n-BuLi and THF, followed by oxidation of the benzocyclobutenol intermediates to provide benzocyclobutenones. The [2+2] reaction can be run on
Rhodium-Catalyzed Regioselective Carboacylation of Olefins: A CC Bond Activation Approach for Accessing Fused-Ring Systems
作者:Tao Xu、Guangbin Dong
DOI:10.1002/anie.201202771
日期:2012.7.23
Cut and sew: A rhodium‐catalyzed regioselective carboacylation reaction of benzocyclobutenones was developed (see scheme). Directed by the pendant olefins, the C1C2 bond is selectively cleaved rather than the C1C8 bond. Subsequent alkene insertion leads to complex fused‐ring systems. This reaction provides facile access to natural‐product‐like polycyclic structures in a chemoselective and atom‐economic