@article {2528,
	title = {Synthesis and Characterization of a New Thiophene-Bridged Diamidophosphine [NPN] Donor Set and Its Coordination Chemistry with Zirconium(IV): Unexpected Deprotonation-Lithiation Sequence with a Mesitylaminothiophene Precursor},
	journal = {Organometallics},
	volume = {28},
	number = {17},
	year = {2009},
	note = {ISI Document Delivery No.: 489MMTimes Cited: 1Cited Reference Count: 43Menard, Gabriel Jong, Howard Fryzuk, Michael D.},
	month = {Sep},
	pages = {5253-5260},
	type = {Article},
	abstract = {The synthesis and characterization of the thiophene-bridged diamidophosphine proligand [NPN]H-S(2) (2) (where [NPN]H-S(2) = {[N-(2,4,6-Me3C6H2)(3-NH-SC4H2-2-)](2)PPh}) along with several [NPN](ZrX2)-Zr-S (X = NMe2, Cl, I) complexes are presented. The ligand precursor [NPN]H-S(2) was prepared from N-(2,4,6-Me3C6H2)(3-NH-4-Br-SC4H2) (1),(BuLi)-Bu-t, and PhPCl2 in Et2O in 50\% yield; the stereochemistry of the ligand precursor was unexpected and likely resulted from a competitive bromine-lithium exchange and deprotonation sequence with the thiophene starting material I and (BuLi)-Bu-t. A mechanism to rationalize the observed stercochemistry of the product is proposed following deuteration experiments. [NPN]Zr-S(NMe2)(2) (8) can be prepared in 80\% yield by the direct reaction of [NPN]H-S(2) and Zr(NMe2)(4) in toluene. Both [NPN](ZrCl2)-Zr-S (9) and [NPN](ZrI2)-Zr-S (10) are prepared in high yield by the reaction of 8 with excess Me3SiCl or Me3SiI, respectively.},
	keywords = {DIARYLAMIDO-PHOSPHINE-LIGANDS, DIRECTED ORTHO-LITHIATION, END-ON, hafnium, HALOGEN EXCHANGE, lithium, METAL-COMPLEXES, MOLECULAR NITROGEN, ON-BOUND DINITROGEN, PALLADIUM-CATALYZED AMINATION, SIDE-ON},
	isbn = {0276-7333},
	url = {<Go to ISI>://000269424200046},
	author = {Menard, G. and Jong, H. and Fryzuk,Michael D.}
}
@article {2549,
	title = {Synthetic Approaches to the Microtubule-Stabilizing Sponge Alkaloid Ceratamine A and Desbromo Analogues},
	journal = {Journal of Organic Chemistry},
	volume = {74},
	number = {3},
	year = {2009},
	note = {ISI Document Delivery No.: 402HHTimes Cited: 6Cited Reference Count: 58Nodwell, Matt Pereira, Alban Riffell, Jenna L. Zimmerman, Carla Patrick, Brian O. Roberge, Michel Andersen, Raymond J.},
	month = {Feb},
	pages = {995-1006},
	type = {Article},
	abstract = {Two synthetic approaches to the microtubule-stabilizing ceratamine alkaloids are described. The first approach involved attempts to graft an aminoimidazole moiety onto an azepine ring to form partially hydrogenated versions of the unprecedented aromatic imidazo[4,5-d]azepine core of the ceratamines. This route ultimately failed because it was not possible to aromatize the partially hydrogenated ceratamine intermediates. A second approach started with tribromoimidazole that was sequentially metalated and functionalized to efficiently generate a key imidazole intermediate containing vinyl bromide and amide functionalities. An intramolecular Buchwald vinyl amidation reaction converted this key intermediate into a bicyclic imidazol[4,5-d]azepine that was at the same oxidation state as the aromatic core of the ceratamines. The 2-amino functionality present on the imidazole ring of the ceratamines was installed using a Buchwald/Hartwig amination reaction on a 2-chloroimidazole precursor. Deprotection and aromatization resulted in the first synthesis of desbromoceratamine A (55) and desmethyldesbromoceratamine A (60). An unanticipated addition of atmospheric oxygen was encountered during deprotection of the imidazole ring in the last step of the synthesis leading to C-11 oxygenated ceratamine analogues as byproducts. Evaluation of the synthetic ceratamines in a TG3 cell-based assay for mitotic arrest revealed that the C-14 and C-16 bromine substituents in ceratamine A (1) play a major role in the antimitotic potency of the natural product. The synthetic route to ceratamine analogues has provided sufficient quantities of desbromoceratamine A (55) for testing in mouse models of cancer.},
	keywords = {6-PI-2-AZATRIENE ELECTROCYCLIZATION, AGELADINE-A, ANTIMITOTIC AGENTS, ARYL CHLORIDES, DIRECTED LITHIATION, HALIDES, IMIDAZOLE, PACLITAXEL, PALLADIUM-CATALYZED AMINATION, TAXOL},
	isbn = {0022-3263},
	url = {<Go to ISI>://000263004300005},
	author = {Nodwell, M. and Pereira, A. and Riffell, J. L. and Zimmerman, C. and Patrick, B. O. and Roberge, M. and Andersen, R. J.}
}
