Atom‐Economic, Regiodivergent, and Stereoselective Coupling of Imidazole Derivatives with Terminal Allenes

Abstract

New Rh‐ and Pd‐catalyzed regiodivergent and stereoselective intermolecular coupling reactions of imidazole derivatives with mono‐substituted allenes are herein reported. Using a RhI/Josiphos system, perfect regioselectivities and high enantiomeric excess were obtained, while a PdII/dppf system gave linear products with high regioselectivities and high E/Z selectivities. This method permits the atom economic synthesis of valuable branched and linear allylic imidazole derivatives.

Bu4NHSO4‐Catalyzed Direct N‐Allylation of Pyrazole and its Derivatives with Allylic Alcohols in Water: A Metal‐Free, Recyclable and Sustainable System

“…13 C NMR (101 MHz, CDCl 3 ) δ 159. 8, 159.7, 141.0, 139.6, 137.4, 133.6, 129.8, 129.5, 128.6, 127.4, 119.6, 119.4, 113.9, 113.3, 113.2, 111.9, 105.6, 67.4, 13 C NMR (101 MHz, CDCl 3 ) δ 156. 9, 156.7, 139.4, 129.3, 129.0, 128.8, 128.4, 128.1, 128.0, 127.7, 127.4, 125.4, 120.8, 120.…”

“…Light yellow viscous oily liquid; 165.5 mg, 87% isolated yield; 1 H NMR (400 MHz, CDCl 3 ) δ 7.52 (dd, J = 50.2, 2.1 Hz, 2H), 6H),6.56 (dd,J = 15.8,6.7 Hz,1H),2H),6.10 (d,J = 6.8 Hz,1H),12H). 13 C NMR (101 MHz, CDCl 3 ) δ 149. 10, 149.06, 148.9, 148.7, 139.5, 133.1, 132.0, 129.0, 128.5, 125.4, 120.0, 119.6, 111.0, 110.9, 110.5, 108.9, 105.5, 67.3, 55.82, 55.80, 55.77…”

“…White solid; 193.8 mg, 88% isolated yield; 1 H NMR (400 MHz, CDCl 3 ) δ 7.62 (dd, J = 1.8, 0.7 Hz, 1H), 7.52 (d, J = 2.3 Hz, 1H), 3H),6.42 (s,2H),2H),6.10 (d,J = 6.6 Hz,1H),18H). 13 C NMR (101 MHz, CDCl 3 ) δ 153. 6, 153.5, 139.9, 138.5, 137.86, 135.2, 134.0, 131.8, 128.81, 128.80, 126.7, 105.8, 104.5, 104.0, 67.8, 61.08, 61.06, 60.96, 60.94, 56.29, 56.28, 56.26.…”

“…[12] And Breit et al have made an outstanding contribution on synthesizing a series of chiral allylic pyrazole derivatives with high enantioand regioselectivities catalyzed by corresponding Rh or Pd complexes. [13] Alcohols are important chemical raw materials because of its low toxicity, wide existence in nature. In traditional ways for the transformation of allylic alcohols into allylic amines, the hydroxyl group of allylic alcohols due to poor leaving ability generally needs to be pre-activated into easily leaving groups such as carboxylates, halides, diazo compounds and so on, which would produce a series of by-products (Scheme 1, Path c).…”

Synthesis of medicinally relevant oxalylamines via copper/Lewis acid synergistic catalysis

“…1C ) ( 28 , 29 ). Despite extensive efforts dedicated to developing efficient methods for aminative functionalization of allenes, there are still great challenges owing to regio- and stereocontrol as well as reactivity issues: (i) The unique accumulated diene structural units have greatly limited the selective activation of the two carbon-carbon double bonds of allenes ( 30 ). (ii) Efficient selective synthesis of Z -allylamines remains a challenging task for their thermodynamic instability ( 31 – 34 ).…”