Selective Formation of Functionalized α-Quaternary Malononitriles toward 5,5-Disubstituted Pyrrolopyrimidinones.

A modular, selective approach to complex α-tertiary substituted malononitriles is reported. The method takes advantage of ß-ester-substituted α,α-dinitrile alkenes as highly reactive, chemoselective electrophiles for 1,4-additions with organometallic nucleophiles to produce functionally and sterically dense all-carbon quaternary centers. In the presence of a chiral ester auxiliary bearing an aromatic ring, the 1,4-addition occurs with good to excellent selectivity due to favorable cation-π interactions. The highly functionalized malononitriles represent versatile building blocks and can be applied toward efficient, highly selective syntheses of 5,5-disubstituted pyrrolopyrimidinones.

Drug Guru: a computer software program for drug design using medicinal chemistry rules.

Drug Guru (drug generation using rules) is a new web-based computer software program for medicinal chemists that applies a set of transformations, that is, rules, to an input structure. The transformations correspond to medicinal chemistry design rules-of-thumb taken from the historical lore of drug discovery programs. The output of the program is a list of target analogs that can be evaluated for possible future synthesis. A discussion of the features of the program is followed by an example of the software applied to sildenafil (Viagra) in generating ideas for target analogs for phosphodiesterase inhibition. Comparison with other computer-assisted drug design software is given.