Mirroring Enzymes: The Role of H-Bonding In HQuin-BAM Catalyzed Asymmetric Aza-Henry Reactions: A DFT Study into the Reactivity, Mechanism, and Origins of Selectivity

The exact mechanistic understanding of various organocatalytic systems in asymmetric reactions such as Henry and aza-Henry transformations is important for developing and designing new synthetic organocatalysts. The focus of this dissertation will be on the use of density functional theory (DFT) for studying the asymmetric aza-Henry reaction. The first part of the thesis is a detailed mechanistic investigation of a poorly understood chiral bis(amidine) (BAM) Brønsted acid catalyzed aza-Henry reaction between nitromethane and N-Boc phenylaldimine. The catalyst, in addition to acting as a Brønsted base, serves to simultaneously activate both the electrophile and the nucleophile through dual H-bonding during C-C bond formation and is thus essential for both reaction rate and selectivity. Analysis of the H-bonding interactions revealed that there was a strong preference for the formation of a homonuclear positive charge-assisted H-bond, which in turn governed the relative orientation of substrate binding. Attracted by this well-defined mechanistic investigation, the other important aspect of my PhD research addressed a detailed theoretical analysis accounting for the observed selectivity in diastereoselective versions of this reaction. A detailed inspection of the stereodetermining C-C bond forming transition states for monoalkylated nitronate addition to a range of electronically different aldimines, revealed that the origins of stereoselectivity were controlled by a delicate balance of different factors such as steric, orbital interactions, and the extent of distortion in the catalyst and substrates. The structural analysis of different substituted transition states established an interesting dependency on matching the shape and size of the catalyst (host molecule) and substrates (guest molecules) upon binding, both being key factors governing selectivity, in essence, offering an analogy to positive cooperative binding effect of catalytic enzymes and substrates in Nature. In addition, both intra-molecular (intra-host) and inter-molecular (host-guest, guest-guest) stabilizing interactions play a key role to the high π-facial selectivity. The application of dispersion-corrected functionals (i.e., ωB97X-D and B3LYP-D3) was essential for accurately modeling these stabilizing interactions, indicating the importance of dispersion effects in enantioselectivity. As a brief prelude to more extensive future studies, the influence of a triflate counterion on both reactivity and selectivity in this reaction was also addressed.

Indenture of Land Sold by David Secord to George Shaw, Richard Woodruff, Timothy Street, Josiah Brown, Henry Pope

Indenture regarding land sold by David Secord of St. Davids to George Shaw, Richard Woodruff, Timothy Street and Josiah Brown, all of Niagara Township and Reverend Henry Pope of York. The land includes part of Lot no. 90 in the Township of Niagara. September 5, 1820.

Second Welland Canal - Book 3, Survey Map 2 - Canal to Chippewa Creek with Port Robinson

Survey map of the Second Welland Canal created by the Welland Canal Company showing the canal as it passes through Port Robinson. Identified structures associated with the Canal include the Guard Lock, Collector Toll Office, towing path, and the New Cut of the canal. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include streets and roads (ex. Island Street, Bridge Street, John Street, and Cross Street), bridges (Swing Bridge, and several unnamed bridges), Welland Railroad, Canal to Chippewa Creek (and two old locks and one new lock associated with the canal), Chippewa Creek, Back Water, an unnamed Island, Dry Dock leased to McFarland and Abbey, Abbey's Office, D. McFarland and Co. Saw Mill (Burnt), G. Jordan Tavern, Robert Elliot Store House and Wharf, Isaac Pew's Shop, Colemans Hotel, R. Band and Co. Girst Mill, Donaldson and Co. Grist Mill, H. Marlatt Dwelling House and barn, Henry W. Timms Hotel, Methodist Church, Post Office, Blacksmith Shop, a church, a structure labeled B. Patch, and a number of other structures that are not named. Properties and property owners of note are: Lots 202 and 203, S. Hill, D. McFarland, Church Society, G. Jordan, D. Coleman, John Brown, Rob Coulter, Robert Elliot, Isaac Pew, James McCoppen, William Bell, Charles Stuart, Andrew Elliot, Robert Band, Ed. Feney, John Betty, F. Sharp, William B. Hendershot, A. Brownson, H. Marlatt, J. S. Powell, and the School Trustees. Two reserved properties are labeled in red.The current spelling of Chippewa Creek is Chippawa. Although it not possible to make out the entire name of the H. W. Timms hotel located at Front and Bridge Street on the map itself, it was discovered to belong to Henry W. Timms after consulting the 1851-52 Canada Directory.

Erie & Niagara Railway Collection, 1864-1884

William Alexander Thomson (1816-1878) was a promoter and developer of railway systems in western Ontario. He incorporated the Fort Erie Railroad Company in 1857, purchased the Erie and Ontario Railroad in 1863, and incorporated the Erie and Niagara Extension Railway Company in 1868 (later renamed the Canada Southern Railway). Thomson was also elected to the House of Commons for Welland in 1872, and re-elected in 1874. He was known for his support of public management of the currency and is seen as a pioneer advocate of government monetary policy. He was also an advocate of radical agrarian economic doctrine, believing that Canadian laws favoured mercantile interests over those of the producers of goods, and that this hindered national development.

Niagara Ship Canal : letter from the Secretary of War, transmitting report by Colonel Blunt, on the surveys for a ship canal to connect Lakes Erie and Ontario (1868)

March 3, 1868. -- Referred to the Select Committee on the Niagara Ship Canal.

Photograph - Emma Osgood Mead, Osgood Woodruff, and Henry C. Woodruff

Black and white photograph, 6 ½ cm x 10 cm, of 2 women and a man. The inscription on the back reads “Emma Osgood Mead (“Blind Aunt Emma”), Osgood Woodruff and Henry C. Woodruff (Mrs. Percy Band’s father was a cousin to this ‘Uncle Henry’).

Indenture between Henry Mittleberger and Cadwallader Griffith Pelton

Indenture between Henry Mittleberger of St. Catharines and Cadwallader Griffith Pelton of St. Catharines for the sale of part of Lot no. 18 in the 6th Concession in the Township of Grantham - Instrument no. 11.013. May 6, 1836.

Indenture between Johnson T. Butler, Ann Jane Butler and Henry Rogers

Indenture of bargain and sale between Johnson T. Butler and his wife Ann Jane Butler, both of the Township of Niagara to Henry Rogers of the Township of Niagara regarding part of Lot no. 113 in the Township of Niagara - instrument no. 14467 [it is listed as 14467 and 14466 on different parts of the document], April 13, 1864.

Indenture between Henry and Mary Ellen Rogers and John Young

Indenture of bargain and sale between Henry and Mary Ellen Rogers of the Township of Niagara and John Young of the Township of Niagara regarding part of Lot no. 113 in the Township of Niagara - instrument no. 15071. Registered in the County of Lincoln on January 16, 1865 in Book C, folio 344, January 13, !865.

Indenture between Henry Hope Graham and Robert Hill to Joseph Walker

Indenture of deed of land situate between Henry Hope Graham and Robert Hill, both of London, England called England Esquire Executors and Trustees under the Last Will and Testament of Lieutenant General Percy Hill of London, England to Joseph Walker of Queenston, Ontario. This is in regard to parts of Lots no. 113, 114 and 115 in the Township of Niagara. This was registered on Nov. 10, 1885 – instrument no. 2075, Oct. 31, 1885.

Invitation to the Funeral of Infant Henry Howard Woodruff

Invitation to the funeral of infant Henry Howard Woodruff on March 17, 1868. He was the son of Henry and Emma Woodruff. This is accompanied by an envelope. March 16, 1868.

Indenture Abraham Fuller Atkinson, Henry Riggs Goodman and William Hamilton Merritt to Thomas Lees Helliwell

Indenture between Abraham Fuller Atkinson of St. Catharines, rector of St. George’s Church, Henry Riggs Goodman and William Hamilton Merritt, wardens of St. George’s Church, to Thomas Lees Helliwell for pew no. 15 in St. George’s Church, Mar. 21, 1857.

Crick, Henry A., includes Application for Loan, and Mortgage Loan Envelope

Crick, Henry A., includes Application for Loan, Jan. 8, 1885 and Mortgage Loan Envelope no. 637 for Jan. 1, 1885 – Jan. 1, 1890.

Time on marsh lands for the months of January, February, March and April for Fred Holmes, Joseph Simpson, Duncan Davidson, Rose Osborne, Henry Wilson and William Baird

Time on marsh lands for the months of January, February, March and April for Fred Holmes, Joseph Simpson, Duncan Davidson, Rose Osborne, Henry Wilson and William Baird. This is signed by Fred Holmes, April 28, 1857.

Engineering services in marsh lands drainage for the months of January, February, March and April for Fred Holmes, Joseph Simpson, D. Davidson, Rose Osborne, Henry Wilson and William Baird

Engineering services in marsh lands drainage for the months of January, February, March and April for Fred Holmes, Joseph Simpson, D. Davidson, Rose Osborne, Henry Wilson and William Baird. This is signed by S.D. Woodruff, May 1, 1857.