Regio- and Diastereoselective Synthesis of Dihydropyridopyrimidines via Cascade Reactions of 2‑Aminopyridines with Morita–Baylis–Hillman Bromides of Nitroalkenes Lakshminarayana Satham Irishi N. N. Namboothiri 10.1021/acs.joc.7b00947.s002 https://acs.figshare.com/articles/journal_contribution/Regio-_and_Diastereoselective_Synthesis_of_Dihydropyridopyrimidines_via_Cascade_Reactions_of_2_Aminopyridines_with_Morita_Baylis_Hillman_Bromides_of_Nitroalkenes/5087161 The Morita–Baylis–Hillman (MBH) bromides of nitroalkenes have been employed as bielectrophiles for the first time. The 1,3-bielectrophilic reactivity of the MBH bromides has been demonstrated in the synthesis of 3,4-dihydro-2<i>H</i>-pyrido­[1,2-<i>a</i>]­pyrimidines. The reaction of MBH bromides with 2-aminopyridines takes place in the absence of any reagent in a cascade S<sub>N</sub>2′-6-endo-trig fashion and is completely regioselective and highly stereoselective. The products, in their hydrobromide salt form, could be conveniently isolated and purified by crystallization. The high stereoselectivity has been rationalized in terms of the greater stability of the transition state in which the Ar and NO<sub>2</sub> groups are anti to each other. 2017-05-24 00:00:00 hydrobromide salt form MBH bromides Morita