Xiaohu Zhao

Chiral Lewis acid catalyzed asymmetric cycloadditions of disubstituted ketenes for the synthesis of β-lactones and δ-lactones.

Highly diastereo- and enantioselective [2 + 2]- and [4 + 2]-cycloadditions of disubstituted ketenes were realized by chiral Lewis acid catalysis. A series of arylalkylketenes underwent the reaction smoothly with isatins and β,γ-unsaturated α-ketoesters, providing optically active β-lactones and δ-lactones with vicinal chiral centers in excellent yields (up to 99%) and enantioselectivities (up to 99% ee), as well as exclusively high diastereoselectivities under 0.2-2 mol % catalyst loading.

Novel Molecular Events in Oral Carcinogenesis via Integrative Approaches

Cancer is now viewed as a systems biology disease, and oral squamous cell carcinoma (OSCC) can be viewed in a similar fashion. In this paper, we highlight some of the novel molecular events in OSCC, revealed through an integrative strategy of systems biology based on high-throughput omics analysis such as genomics and/or proteomics, the most powerful hypothesis-generating means available today. These approaches have resulted not only in the identification of novel genes for OSCC, but also in more comprehensive networks that describe the mechanisms by which those identified events work, with the promise of developing this knowledge into biomarkers for diagnosis, prognosis, and prediction of therapeutic responses in OSCC patients. Long-term, population-based prospective studies of OSCC patients, and those at high risk of developing OSCC, will then be needed to validate these biomarkers.