02336nas a2200181   4500008004100000022001400041245012700055210006900182260000800251300000800259490000600267520165900273100003201932700002201964700002301986700002202009856012302031       2026                        eng d  a2399-366900aLeveraging Lewis acid catalysis for cascade construction of multisubstituted furans from active methylenes and 3-oxetanone0 aLeveraging Lewis acid catalysis for cascade construction of mult  cMAY  a2530 v93 a<p>
	The synthesis of multisubstituted furans, those incorporating further functionalizable groups, remains a significant challenge in organic synthesis. These difficulties largely arise from reliance on prefunctionalized substrates, multistep sequences, harsh conditions, and costly catalytic systems. Herein, we report a rapid, efficient, and operationally simple cascade [3 + 2]-annulation that addresses these limitations while delivering step and atom economy. The method exploits readily available and inexpensive active methylene compounds (beta-ketoesters, beta-diketones, and related derivatives) as C-C-O 1,3-bis-nucleophiles, in combination with 3-oxetanone as a C-C 1,2-bis-electrophile, under catalysis by sustainable and low-cost Fe-salts. This protocol enables the construction of diverse multisubstituted and fused furan architectures, bearing alkyl, cycloalkyl, alkynyl, aryl, and heteroaryl substituents, as well as functional groups derived from nitriles, sulfones, phosphonates, and amides. The synthetic utility of the approach is further demonstrated by the total synthesis of biologically active methylenomycin furans (MMFs) and methylfuroic acid, and formal syntheses of evodone, tubipofuran, menthofuran, maturone, isomaturone, and rabdoketones. Moreover, the method proves highly effective for late-stage diversification, as illustrated by the functionalization of bioactive natural products, including beta-ionone, tonalide, progesterone, and pregnenolone. Collectively, this strategy provides a practical, versatile, and sustainable platform for the streamlined synthesis and diversification of multisubstituted furans.</p>
1 aSahoo, Shubhranshu, Shekhar1 aKataria, Priyanka1 aIngale, Sudhir, R.1 aKontham, Ravindar  uhttps://library.ncl.res.in/content/leveraging-lewis-acid-catalysis-cascade-construction-multisubstituted-furans-active