Chemoselective conversion of azides to t-butyl carbamates and amines

Triborane (B3H7)-mediated regioselective substitution reactions of pyridine derivatives

There exists an interplay between borane and a Lewis base in their adducts. However, studies on these adducts so far have mainly focused on the different reactions of B-H bonds with limited attention given to the influence of borane on the chemistry of the Lewis base, except for BF3 and BAr3. Herein, we have synthesized novel borane adducts with pyridine derivatives, Py·B3H7, in which the coordination of B3H7 efficiently achieved the intra-molecular charge transfer. The strong B-N bond in these adducts resulted in the formation of stable dearomatic intermediates of pyridine derivatives, confirmed by 1H and 11B NMR spectroscopy, from which different reactions have transpired to realize C(sp3)-H and C(sp2)-H functionalization under mild conditions. The B3H7 pyridine derivatives are stable and do not dissociate or decompose during the reaction process. The high stability of the B-N bond makes this method a good option for boron-containing drugs with potential for use in boron neutron capture therapy (BNCT).

Oxidation of Benzylic Azides Catalysed by Iron(III) Chloride with Hydrogen Peroxide as Oxidant

A simple and general method for the oxidation of benzylic azides to aldehydes using the inexpensive and environmentally benign iron (III) chloride as catalyst with 30% aqueous H2O2 as oxidant is described. Broad substrate scope and high tolerance against several functional groups make the process synthetically useful.

Theoretical studies on reductive etherification reactions between aromatic aldehydes and alcohols

The mechanism of reductive etherification reactions between aromatic aldehydes and alcohols has been investigated with the DFT(B3LYP)/6-31G method. One or two BH(3) molecules have been used to simulate the role of the catalyst and reducing agent. The solvent effects of the title reactions have been studied by the PCM model. It is found that the reactions between aromatic aldehydes and primary, secondary, and tertiary alcohols can proceed more easily in a polar solvent such as acetonitrile. The results provide evidence in theory to broaden the applications of reductive etherification reactions for the optimization of the radiochemical synthesis process of (18)F-labeled ether radiotracers.