Progress to scalable Molecular Machines

Researchers detail an artificial molecular machine that moves a substrate between different activating sites to achieve different product outcomes from chemical synthesis. This molecular robot can be programmed to stereoselectively produce, in a sequential one-pot operation, an excess of any one of four possible diastereoisomers from the addition of a thiol and an alkene to an α,β-unsaturated aldehyde in a tandem reaction process. The stereodivergent synthesis includes diastereoisomers that cannot be selectively synthesized through conventional iminium–enamine organocatalysis. They anticipate that future generations of programmable molecular machines may have significant roles in chemical synthesis and molecular manufacturing.

Depending on which side the substrate is held for each reaction, a different stereoisomer of the product is formed. The reaction sequences are carried out in one pot and the robot can be programmed to produce selectively each isomer of the product by controlling the switch-state prior to each reaction of the substrate. Each molecular robot manipulates a single substrate molecule, but the process is massively paralleled with more than a million trillion molecular robots operated simultaneously by the scientists.

Nature – Stereodivergent synthesis with a programmable molecular machine