Xinping Han

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A mild two-step process for the regioselective, transition-metal-free preparation of carbon-carbon bonds from allylic alcohols/ethers and Grignard reagents is described. This process obviates the need for the harsh deprotection conditions usually required for removal of methyl ethers. The synthesis is accomplished by photochemically promoted allylic(More)
The α-helix is the most abundant secondary structure in proteins. Due to the specific i, i+4 hydrogen bond pattern, the two termini have unsatisfied hydrogen bonds, and are less constrained; in order to compensate for this, specific residues are preferred for the terminal positions. However, a naive combination of the statistically-preferred residues for(More)
Rational assembly of small molecule libraries for purposes of drug discovery requires an efficient approach in which the synthesis of bioactive compounds is enabled so that numerous structurally related compounds of a similar basic formulation can be derived. Here, we describe (4 + 3) and (3 + 2) indole annulation strategies that quickly generate complex(More)
Secondary role: Indole and pyrrole derivatives are alkylated with unactivated secondary aliphatic alcohols by a Brønsted acid-catalyzed redox chain reaction mechanism. Broad functional-group tolerance has been demonstrated and preliminary studies suggest that 1,4-reduction of a putative indolyl carbocation is the dominant mechanistic pathway.
(IC50= 63 nm) of SIRT1, a member of the class III histone deacetylases (HDAC). SIRT1 can effectively deacetylate p53 and has also been implicated in the regulation of apoptosis. With an IC50 of 100 nm, compound 3 inhibits the production of leukotriene B4 (LTB4) which is involved in various inflammatory responses. A third molecule, 4, inhibits the adipocyte(More)
1-Phenyl-1H-tetrazole-5-thiol 1 (PT-thiol) is employed in a unique Markovnikov-selective formal hydroamination of styrenyl compounds in the presence of catalytic amounts of Ga(OTf)3. This gives rise to the formation of tetrazolothione moieties in an atom-economical manner. Mechanistically, we have determined that this transformation may occur by kinetically(More)
Organozirconocenes are versatile synthetic intermediates that can undergo carbonylation to yield acyl anion equivalents. Zirconocene hydrochloride ([Cp2 ZrHCl]) is often the reagent of choice for accessing these intermediates but generates organozirconocenes only from alkenes and alkynes. This requirement eliminates a broad range of substrates. For example,(More)
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