Is it possible to add methane sulfonyl chloride to benzaldehyde cyanohydrin, or add toluene sulfonyl chloride to form the tosylate group on the alcohol and then perfom a grignard reaction on the nitrile to form an imine? Or more succinctly do mesylate/tosylate sulphonyl chlorides react with nitriles as they do with amines.
Yes, according to Kiritsis et al.  it is possible to mesylate cyanohydrins.
The paper by Bracco et al.  has a number of relevant examples such as protection of the cyanohydrin by O-silylation followed by Grignard addition and O-triflation followed by Suzuki coupling of the triflate with arylboronic acid. It also shows that the −OH group may also be acetylated and the tetrahydropyranyl or t-butyl ether can be formed.
- Kiritsis, C.; Manta, S.; Dimopoulou, A.; Parmenopoulou, V.; Gkizis, P.; Balzarini, J.; Komiotis, D. Stereoselective Facile Synthesis of 2′-Spiro Pyrimidine Pyranonucleosides via Their Key Intermediate 2′-C-Cyano Analogues. Evaluation of Their Bioactivity. Carbohydrate Research 2014, 383, 50–57. DOI: 10.1016/j.carres.2013.11.001.
- Bracco, P.; Busch, H.; von Langermann, J.; Hanefeld, U. Enantioselective Synthesis of Cyanohydrins Catalysed by Hydroxynitrile Lyases – a Review. Org. Biomol. Chem. 2016, 14 (27), 6375–6389. DOI: 10.1039/C6OB00934D.