Traditional approaches for the direct preparation of alkenes are unable to fully control either the stereochemical configuration of the carbon-carbon double bond or else the regiochemistry of the substituents surrounding it. The recently introduced concept of carbenoid eliminative cross-coupling (CEXC) offers a remedy to these deficiencies by providing for a...
Ambifunctional axially chiral 2,2',6,6'-tetrasubstituted biphenyls containing nucleophilic (or basic) functional groups juxtaposed with hydrogen-bond donors were synthesized and their properties studied. Applications for the prepared biaryls as potential organocatalysts for enantioselective carbon-carbon bond forming reactions were examined. Processes investigated included: aldol, Michael, nitroaldol (Henry), and Baylis-Hillman reactions.
The novel amidoamine...
In previous work (Blakemore et al. Org. Lett. 2005, 7, 4721; Heterocycles 2006, 70, 609), successful elaborations of the lupine alkaloids (±)-α-isosparteine (dl-2) and (±)-β-isosparteine (dl-3) were realized from a common tetraoxobispidine precursor, 3,7-diallyl -2,4,6,8-tetraoxo-3,7-diazabicyclo[3.3.1]nonane (93). Herein, the tetraoxobispidine approach to lupine alkaloids was extended to a total synthesis of...
Two distinct strategies were explored for the enantioselective synthesis of α-heteroatom substituted alkyl boronic esters by stereoselective reagent-controlled homologation using transient chiral carbenoid reagents CHYMX (Y = heteroatom, X = nucleofuge, M = electrofuge). In the first case, a stereospecific reagent-controlled homologation (sStReCH) approach to α-alkoxyalkylboronates using α-metalated S,O- and...
Enantioenriched sp³-hybridized carbenoid reagents CR1R2MX (X = nucleofuge, M = electrofuge) of different types were investigated for the synthesis of polysubstituted alkyl chains by iterative stereospecific reagent-controlled homologation (StReCH) and for the stereospecific connective synthesis of alkenes by eliminative cross-coupling.
In the first part, putative enantioenriched α-chloroalkyllithiums (CHRLiCl) were employed...
The synthesis of axially chiral polyfunctional derivatives of 8,8'-biquinolyl was explored and the catalytic action of appropriate derivative types investigated in three separate processes: (1) the silylcyanation of carbonyl groups and imines, (2) alkylation of a glycine Schiff-base via phase transfer-catalysis, and (3) direct amide bond formation from simple amines...
A comparison of the various endocrine glands, in addition to
other anatomical measurements, was made on 19 normal and 21
dwarf 2-3-month-old females and 20 normal and 20 dwarf 7-13-month-old females of the White Leghorn breed. At both ages, dwarfs
weighed significantly less and had significantly shorter shanks than
normals....
Benomyl-tolerant Botrytis cinerea was found in snap
bean fields throughout the Willamette Valley while no tolerant
isolates of Whetzelinia sclerotiorum were detected.
Thirty-five benomyl-tolerant isolates of B. cinerea had
slower radial growth rates than eighteen benomyl-sensitive
isolates. Sporulation of an aggressive tolerant isolate
was not stimulated when grown on benomyl-treated...
A study of the immature stages of the subfamily Troginae in
North America was conducted from the spring of 1963 through the
spring of 1965, Larvae of Trox and Omorgus were easily reared in
the laboratory, but all attempts to rear the larvae of Glaresis were
unsuccessful,
The suberosus group,...
My work on computing complex catalyzed organic transformations reveals that only a few subtle chemical factors, e.g. non-classical hydrogen bonding, (hyper)conjugation and steric effects, common across different catalyst manifolds are critical for catalysis and selectivity. Rational manipulation and exploitation of these factors has led to improved catalyst designs, which has...