Hydroborations: A New Convenient Route for the Preparation of 4-Alkyl- (or 4-Aryl)chroman-3-ones from 4-Alkyl- (or 4-Aryl)-2H-chromenes

Time-Resolved Absorption Studies on the Photochromic Process of 2H-Benzopyrans in the Picosecond to Submillisecond Time Domain

“…4-Phenyl-2H-benzopyran (4-PhBP) 40,41 and 2,4-diphenyl-2Hbenzopyran (2,4-Ph 2 BP) 40,41 were prepared by dehydration of the products of the Grignard reactions of bromobenzene with 4-chromanone and flavanone, respectively.…”

Synthesis of 3,4-Disubstituted 2H-Benzopyrans through C−C Bond Formation via Electrophilic Cyclization

“…Substituted 2H-benzopyrans have been synthesized in our laboratories by the Pd(II)-catalyzed cyclization of allylic aryl ethers, 7 while the palladium-catalyzed cross-coupling of 4-trifluoromethanesulfonyloxy-2H-benzopyrans with arylboronic acids has also been reported in the literature. 8 Syntheses of 2Hbenzopyrans are also known using platinum and gold catalysis, 9 Hg(II)-mediated cyclizations, 10 Grignard reagents, 11 and microwave irradiation. 12 A wide range of carbocycles and heterocycles have been constructed using the electrophilic cyclization of disubstituted alkynes 13 and transition metal-catalyzed cyclizations.…”

PtIV‐Catalyzed Cyclization of Arene—Alkyne Substrates via Intramolecular Electrophilic Hydroarylation.

“…Water was added and the crude product was extracted with CH 2 Cl 2 , S6 dried over MgSO 4 , and concentrated in vacuo. The residue was purified by column chromatography on silica gel by eluting EtOAc-hexane.Compounds 1 9 , 3 10 , 4a 11 , 6a11 , 6b12 , 6c13 , 1114 , 1214 are known and 2a and 27 are commercially available.a. Yields were determined by the mass recovery of the purified reaction mixture and the ratio was determined S7 by1 H NMR of the mixture.O3…”