Reductive coupling and related reactions with Mo and Ti tris- anilides

Chapter 1: The capability of Mo(N[t-BulAr)₃ to act as a powerful one, two, and three electron reductant have been previously demonstrated. In this work, we show that Mo(NIt-BulAr)₃ forms a metastable adduct with the moderate [pi] acid PhCN; coordination of PhCN activates the nitrile carbon towards reaction with a variety of one-electron reagents such as dichalcogenides, nitric oxide, hydrogen atom donors, cobaltocene, and elemental phosphorus. Evidence is presented for the existence of an inner-sphere electron transfer mechanism for these reactions. Chapter 2: With the facile cleavage of N₂ by Mo(Njt-Bu]Ar)₃ already established, a Mo(NIt-Bu]Ar)₃-mediated process for the incorporation of N₂ into organic molecules is an exciting prospect; its realization depends critically on the development of methods for cleavage of the Mo-N bond formed in the early stages of the process. In this chapter, we demonstrate that appropriately-substituted Mo(IV) ketiminates (synthesized using the methods of Chapter 1) undergo [beta]-elimination to cleave the Mo-N bond and liberate PhCN. We present the kinetics of the reaction, substituent effects, and-in three cases - activation parameters. Chapter 3: Deprotonation of the titanium formate complex (ArIt-BuJN)₃TiOC(O)H with LiN(i-Pr)₂ resulted in the release of free CO and the formation of a titanium(IV) oxoanion complex, isolated as its lithium salt. Chapter 4: Previous work from these labs has shown that the unique combination of well-defined composition, steric bulk, and strong reducing ability embodied in Ti(N[t- Bu]Ar)₃ lends itself particularly well to mechanistic studies of the classical Pinacol coupling.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Mendiratta, Arjun

Advisor dc:contributor.advisor

• Christopher C. Cummins.

• Chemistry.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/32483

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/32483