Hydroboration is an important and fundamental reaction system in organic chemistry. Hydroboration of unsaturated hydrocarbons such alkynes, alkenes is an effective and straight-forward method for the preparation of alkene and alkyl boronates which are versatile building blocks in various chemical transformations and metal mediated cross-coupling reactions.1-2 In recent days much attention is focusing on catalyzed hydroborations, leading to its rapid application starting from transition metals to main group-alkaline earth elements, and lanthanide complexes.
In addition, synthesis of secondary amines through C=N bond reduction is a straight forward and often used in organic synthesis. The traditional hydrogenation with transition metals is well examined. Whereas, hydride reduction with LiAlH4 or NaBH4, is unattractive due to their poor yields. Therefore, efficient and sustainable method with lower active reductants are needed.
During the course of our search for efficient reductions; we have identified and reported selective hydroboration of aldehydes and ketones with pinacolborane and commercial reagents as catalysts.3-4 In continuation, the present abstract demonstrates that LDBBA catalyzed hydroboration of unsaturated hydrocarbons and imines (Scheme).
1. Chong, C. C.; Kinjo, R. ACS Catal. 2015, 5, 3238− 3259.
2. Obligacion, J. V.; Chirik, P. J. Nat. Rev. Chem. 2018, 2, 15-34.
3. Shin, W. K.; Kim, H.; An, D. K. Tetrahedron. 2018, 74, 6310-6315.
4. Yang, S. J.; Jaladi, A. K.; Kim, K. H.; Gundeti, S.; An, D. K. Bull. Korean Chem. Soc. 2019, 40, 34–38.