One-Pot γ-Lactams

Synthesizing substituted γ-lactams, which are key intermediates in the synthesis of medicinal leads and natural products, has generally required at least four separate reaction steps. Jingqiang Wei and Jared T. Shaw of Harvard University and MIT's Broad Institute now have devised a one-pot, four-component reaction (shown) that can be used to assemble substituted γ-lactams all in one go (Org. Lett., DOI: 10.1021/ol701911u). The starting materials are amines, maleic anhydrides, aldehydes, and thiols containing different organic functional groups (R¹–R⁴), which can be varied flexibly. The reactants combine in refluxing toluene to yield a wide range of γ-lactam products and water as a by-product. Each γ-lactam has two or three contiguous stereocenters that form with high selectivity. "This reaction should prove useful in the rapid synthesis of collections of compounds for the discovery of drugs and biological probes," Wei and Shaw write. "We are currently pursuing the synthesis of several natural product targets using this transformation."