Oxidant free rhodium-catalyzed C-C bond formation via C-H bond activation

• Main Author: Feng, Daming
• Other Authors: Loh Teck Peng
• Format: Theses and Dissertations
• Language: English
• Published: 2016
• Subjects: DRNTU::Science::Chemistry::Organic chemistry::Organic synthesis
• Online Access: https://hdl.handle.net/10356/65983
• Institution: Nanyang Technological University

This thesis demonstrated the rhodium-catalyzed direct C-C bond formation via C-H activation process and comprised five chapters: Chapter 1 Transition metal-catalyzed inert C-H bond activation has become one of the most useful methods for the synthesis of precious molecules in modern organic chemistry. Among them, rhodium catalysis was proved to be efficient and sustainable for C-H bond functionalization. In the requirement of green chemistry and atom- and stepeconomy, many efforts have been made to realize an oxidant free C-H bond Chapter 2 The stereospecific construction of synthetically useful Z-type enyamides by Cp*Rhcatalyzed C-H olefinic alkynylation of enamides is described. With good functionality tolerance and operational simplicity, this protocol provides an alternative synthetic opportunity for the ease of access of specific 1,3-enyne derivatives. Chapter 3 Cp*Rh-catalyzed C-H alkynylation of acrylamide derivative is realized using a hypervalent alkynyl iodine reagent. The use of a weakly coordinating directing group was proved to be of critical importance. The protocol is compatible with multiple functional groups and presents high reaction efficiency, which creates a new synthetic pathway to access functionalized 1,3-enyne skeletons. Chapter 4 Cp*Rh-catalyzed directed aromatic C-H olefination with allyl acetate is described using N,N-disubstituted aminocarboyl as the directing group. The catalytic cycle is redox-neutral, through which trans-products are obtained in high to excellent yields. The method exhibits a broad range of functional group compatibility due to the simplicity of reaction conditions adopted and offers a highly effective synthetic strategy in the arena of C-H olefination. Chapter 5 Rhodium-catalyzed direct C-H allylation of acrylamides with allyl acetates is described. The high reaction efficiency, broad functionality tolerance and excellent γselectivity was obtained due to the use of weakly coordinating directing group, tosylimine, which demonstrates a new synthetic pathway for the access of 1,4-diene skeletons.