Ruthenium–Me-BIPAM-catalyzed addition reaction of aryl-boronic acids to benzofuran-2,3-diones for the enantioselective synthesis of 3-aryl-3-hydroxybenzofuran-2-ones
摘要:
We have developed an enantioselective synthesis of 3-aryl-3-hydroxybenzofuran-2-ones via the ruthenium-catalyzed 1,2-addition of arylboronic acids to benzofuran-2,3-diones. The use of RuCl2(PPh3)(3) with a chiral bidentate phosphoramidite ligand [(R,R)-Me-BIPAM] in the presence of a small amount of acetonitrile (20 mol %) gave optically active 3-aryl-3-hydroxybenzofuran-2-ones with up to 96% ee. This reaction is the first example of a catalytic asymmetric 1,2-addition reaction of arylboronic acids to benzofuran-2,3-diones for the highly efficient and enantioselective synthesis of quaternary carbon containing benzofuran-2-ones. (c) 2015 Elsevier Ltd. All rights reserved.
N-heterocyclic carbene catalyzed annulation of benzofuran-2,3-diones and enals: a concise synthesis of spiro-bis-lactone
作者:Ze-Dong Wang、Feng Wang、Xin Li、Jin-Pei Cheng
DOI:10.1039/c3ob41028e
日期:——
The N-heterocycliccarbenecatalyzedannulation of benzofuran-2,3-diones and enals via homoenolate intermediates is described. The reaction provided a direct and efficient method for the synthesis of spiro-bis-lactones. The ketone-carbonyl group annulated products and the ester-carbonyl group annulated products can be obtained as major products with good yields by convenient catalyst regulation. Furthermore