Transition-metal catalyzed cross-coupling has, in many ways, revolutionized synthetic chemistry by providing streamlined syntheses using highly modular building blocks. Despite the widespread application of the Suzuki and Buchwald-Hartwig cross-coupling reactions, utilization of more contemporary cross-coupling protocols is narrower. Progress in applied research using transition- metal catalyzed reactions is often hampered by the necessity for unwieldy substrate syntheses. Seeking to tackle this problem, we have developed two novel C-C bond forming reactions in the context of the oxidative boron Heck reaction that converts simple starting materials into highly useful products which are directly applicable to many powerful synthetic protocols.
Firstly, an aerobic boron Heck reaction has been developed, which facilitates the conversion of feedstock olefins, namely, ethylene and propylene to styrenes and b-methylstyrenes using abundant (hetero)aryl boronic acids. The relevance to complex molecule synthesis is highlighted by a two-step synthesis of the pharmaceutical phenprocoumon.
Secondly, an aerobic boron Heck reaction of cyclobutene has been developed using abundant (hetero)aryl boronic acids. Instead of forming the classical Heck product (3-aryl-cyclobutene) a linear 1-aryl-1,3-diene is generated with complete chemo-, regio- and stereo-selectivity. 1-Aryl- 1,3-dienes have found myriad applications in modern transition-metal catalyzed cross-couplings however the substrates are often prepared by poorly efficient Wittig reactions. Both computational and mechanistic experimental data support a mechanism that proceeds by a classical Heck reaction followed by pericyclic ring opening mechanism for C-C bond cleavage. 1-Aryl-1,3,5-trienes were similarly prepared using alkenyl boronic acids.
|Advisor:||Carrow, Brad P.|
|Commitee:||Schwartz, Jeffrey, Semmelhack, Martin|
|School Location:||United States -- New Jersey|
|Source:||DAI-B 80/04(E), Dissertation Abstracts International|
|Keywords:||Alkenyl boronic acids, Cross-coupling reactions, Pericyclic ring opening|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be