A novel and efficient route to chiral A-ring aromatic trichothecanes—The first enantiocontrolled total synthesis of (-)-debromofiliformin and (-)-filiformin
first enantiocontrolled total synthesis of (-)-debromofiliformin (7a) and (-)-filiformin (7b) starting from 11via the regiocontrolled cyclization of the phenolic allyl alcohol 25 to the A-ringaromatictrichothecane 26, were reported.
作者:Melanie A. S. Blackburn、Corin C. Wagen、M. Raul Bodrogean、Pamela M. Tadross、Andrew J. Bendelsmith、Dennis A. Kutateladze、Eric N. Jacobsen
DOI:10.1021/jacs.3c02960
日期:2023.7.19
A catalytic protio-semipinacol ring-expansion reaction has been developed for the highly enantioselective conversion of tertiary vinylic cyclopropyl alcohols into cyclobutanone products bearing α-quaternary stereogenic centers. The method relies on the cocatalytic effect of a chiral dual-hydrogen-bond donor (HBD) with hydrogen chloride. Experimental evidence is provided for a stepwise mechanism where
<i>N</i>-Iminopyridinium Compounds in Giese Reaction: Photoinduced Homolytic N–N and C–C Bond Cleavage for Cyanoalkyl Radical Generation
作者:Gyuri Han、Jihyun You、Junhyeon Choi、Eun Joo Kang
DOI:10.1021/acs.orglett.4c00565
日期:2024.3.29
photoinduced cyanoalkyl radical addition methodology using N-iminopyridinium reagents derived from cyclic ketones. Mechanistic investigations reveal the association of the excited Hantzsch ester and iminopyridinium with pyridyl radical generation. The ensuing cascade involving homolytic N–N bond and C–C bondcleavage of the pyridyl radical ultimately leads to the formation of cyanoalkyl radical species, leading
This manuscript describes the synthesis of γ-lactam from the nitrogen insertion reaction of cyclobutanones using an oxime as an aminating reagent with a catalytic amount of Brønstedacid. This method was employed with a more stable oxime reagent, which is a precursor analog of hydroxylamine derivatives with explosive properties. The reaction was tolerated by various substituted cyclobutanones and less