Superfast Formation of C(sp²)-N, C(sp²)-P, and C(sp²)-S Vinylic Bonds in Water Microdroplets

We report examples of C(sp(2))-N, C(sp(2))-S, and C(sp(2))-P bond-forming transformations in water microdroplets at room temperature and atmospheric pressure using N-2 as a nebulizing gas. When an aqueous solution of vinylic acid and amine is electrosprayed (+3 kV), the corresponding C(sp(2))-N product is formed in a single step, which was characterized using mass spectrometry (MS) and tandem mass spectrometry (MS2). The scope of this reaction was extended to other amines and other unsaturated acids, including acrylic (CH2=CHCOOH) and crotonic (CH3CH=CHCOOH) acids. We also found that thiols and phosphines are viable nucleophiles, and the corresponding C(sp(2))-S and C(sp(2))-P products are observed in positive ion mode using MS and MS2.