Amine Nucleophilic Addition to Nitro-alkene as a New Reaction Mode for the Synthesis of N-heterocycles

Amine Nucleophilic Addition to Nitro-alkene as a New Reaction Mode for the Synthesis of N-heterocycles: An efficient stereoselective synthesis of polycyclic lactams has been developed using Michael addition of conjugated amino-esters to nitro-alkenes. Using acyclic and cyclic aminoesters, this method provided a promising approach to the synthesis of bicyclic and tricyclic lactam core (5,5; 6,5; 5,5,5; 5,6,5; 6,5,5; 6,6,5 etc) in moderate to excellent yield (up to 95%) and excellent diastereoselectivities (up to 99:1 dr). The key steps in this asymmetric synthesis include a heteroatom Michael-Michael addition followed by reductive amidation to gamma-lactams. Lactam cores are biologically active broad spectrum antibiotics.;Enantioselective Synthesis of Piperidines by Exocyclic Chirality Transfer: Piperidines are very important structural moieties contained in a wide range of biologically active and medicinally significant compounds. An efficient route to chiral piperidines was developed which involved diastereoselective synthesis of substituted piperidines (yields up to 75% with dr up to 10:1 of single isomer) followed by removal of one chiral fragment also called N-deprotection to enantiopure piperidine (yields up to 92%) with 100% chirality retention.;Unique Reactivity of Triazole Gold towards Alkyne Activation to Enones and Chiral Allenes: 1,2,3-Triazole coordinated gold(I) complexes were found as the effective catalysts in promoting propargylic ester/ether rearrangement and sequential allene hydration giving enones with excellent yields (up to 97% yields, 0.2% catalyst loading). This catalyst also catalyzed the more challenging Meyer-Schuster rearrangement (0.5% catalyst loading, up to 98% yields). Unlike other reported Au catalysts, the TA-Au complexes provided effective chirality transfer without racemization over a long period of time, giving enantioriched allenes with excellent stereoselectivity (1% catalyst loading, up to 99% ee).

Name thesis:degree_name

PhD

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2013

Author dc:creator

• Gautam, Lekh Nath Sharma

Contributors dc:contributor

• Xiaodong Michael Shi
• Peter M. Gannett
• Jeffrey L. Petersen
• Bjorn C. G. Soderberg
• Kung K. Wang

• Organic chemistry
• Pharmaceutical sciences

Identifier

https://researchrepository.wvu.edu/etd/356

OAI identifier oai:identifier

oai:researchrepository.wvu.edu:etd-1359