Olefination of α,α'-divinyl ketones through catalytic Meyer-Schuster rearrangement.

The direct olefination of 1,4-dien-3-ones remains a synthetic challenge. A two-step protocol, employing acetylide addition followed by catalytic Meyer-Schuster rearrangement has been developed for the olefination of 1,4-pentadien-3-ones to afford [3]dendralenes. Many of the traditional methods for the Meyer-Schuster rearrangement of alkynyl carbinols are not suitable with these highly unsaturated substrates because of their acid sensitivity.

Cyclization of cross-conjugated trienes: the vinylogous Nazarov reaction.

Cross-conjugated trienoates can be readily prepared from 1,4-pentadien-3-one precursors via a 2-step process: 1,2-addition of lithiated ethynyl ethyl ether followed by rearrangement of the resulting propargylic alcohol with catalytic VO(acac)(2). Treatment of the trienoates with stoichometric (TiCl(4)) or catalytic (Sc(OTf)(3)) Lewis acid provided conjugated alkylidenecyclopentenes via an apparent vinylogous Nazarov cyclization.

In vitro evaluation of two polyhedral boron anion derivatives as linkers for attachment of radioiodine to the anti-HER2 monoclonal antibody trastuzumab.

Improving intracellular retention is important for the use of radiohalogens in radionuclide therapy using internalizing antibodies. Two putative linkers for residualization of radioiodine labels, 7-(4-isothiocyanato-phenyl)undecahydro-7,8-dicarba-nido-undecaborate(1-) ion (NBI) and (4-isothiocyanato-benzylammonio)undecahydro-closo-dodecaborate(1-) (DABI), were analyzed. The anti-HER-2 antibody, trastuzumab, was labeled with iodine-125 using NBI and DABI linkers, and, for comparison, with the para-[(125)I]iodobenzoate (PIB), and Chloramine-T((R)) (CAT) methods.

Radiobromination of anti-HER2/neu/ErbB-2 monoclonal antibody using the p-isothiocyanatobenzene derivative of the [76Br]undecahydro-bromo-7,8-dicarba-nido-undecaborate(1-) ion.

The monoclonal humanized anti-HER2 antibody trastuzumab was radiolabeled with the positron emitter (76)Br (T(1/2) =16.2 h). Indirect labeling was performed using the p-isothiocyanatobenzene derivative of the [(76)Br]undecahydro-bromo-7,8-dicarba-nido-undecaborate(1-) ((76)Br-NBI) as a precursor molecule.

Palladium-catalyzed Heck reactions of styrene derivatives and 2-iodo-p-carborane.

p-Carborane has been vinylated on the 2-B-atom in high yields using the Heck reaction. Thus, the reaction between 2-iodo-p-carborane and various styrenes [4-H-, 4-C(6)H(4)-, 4-Cl-, 4-Br-, 4-NO(2)-, 4-CH(3)O-, and 4-CH(3)-] resulted in the production of the corresponding trans-beta-(2-B-p-carboranyl)styrene in DMF solution when reacted in the presence of silver phosphate and the palladacycle Herrmann's catalyst.