title: Batch and flow photochemical benzannulations based on the reaction of ynamides and diazo ketones. Application to the synthesis of polycyclic aromatic and heteroaromatic compounds.
abstract: Highly substituted polycyclic aromatic and heteroaromatic compounds are produced via a two-stage tandem benzannulation/cyclization strategy. The initial benzannulation step proceeds via a pericyclic cascade mechanism triggered by thermal or photochemical Wolff rearrangement of a diazo ketone. The photochemical process can be performed using a continuous flow reactor which facilitates carrying out reactions on a large scale and minimizes the time required for photolysis. Carbomethoxy ynamides as well as more ketenophilic bis-silyl ynamines and N-sulfonyl and N-phosphoryl ynamides serve as the reaction partner in the benzannulation step. In the second stage of the strategy, RCM generates benzofused nitrogen heterocycles, and various heterocyclization processes furnish highly substituted and polycyclic indoles of types that were not available by using the previous cyclobutenone-based version of the tandem strategy.
authors.affiliation: Department of Chemistry Massachusetts Institute of Technology Cambridge, Massachusetts 02139.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Willumstad
authors.forename: Olesya
authors.initials: O
authors.lastname: Haze
authors.forename: Xiao Yin
authors.initials: XY
authors.lastname: Mak
authors.forename: Tin Yiu
authors.initials: TY
authors.lastname: Lam
authors.forename: Yu-Pu
authors.initials: YP
authors.lastname: Wang
authors.forename: Rick L
authors.initials: RL
authors.lastname: Danheiser
mesh_terms: D000577:Amides / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D003500:Cyclization; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D055668:Photochemical Processes; D011084:Polycyclic Aromatic Hydrocarbons / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000577:Amides; D001391:Azo Compounds; D006571:Heterocyclic Compounds; D007659:Ketones; D011084:Polycyclic Aromatic Hydrocarbons