Alkyl Carbagermatrane Enabled Synthesis of Seven-Membered Carbocycle-Fused Aromatics through Catellani Strategy

Abstract

Synthesis of seven-membered carbocycle-fused aromatics was realized by Catellani reaction using terminally brominated alkyl carbagermatranes through intermolecular cyclization manner. Various functional groups were well tolerated, and this transformation was also expanded to the synthesis of carbocycles of other size. The utility of this method was demonstrated by modification of natural product derivatives and synthesis of bioactive molecules.

Efficient Synthesis of Cyclohepta[b]indoles and Cyclohepta[b]indole‐Indoline Conjugates via RCM, Hydrogenation, and Acid‐Catalyzed Ring Expansion: A Biomimetic Approach

“…Considering the pharmaceutical significance of the cyclohepta[ b ]indole moiety, we finally manifested the utility of our methodology by the straightforward synthesis of an A‐FABP (adipocyte fatty‐acid binding protein) inhibitor (Scheme 7). [22] The synthesis of this compound has previously been reported using Rh [23a] and Pd [23b] catalyzed methods by the Katukojvala and Xiao groups, respectively (Scheme 7A and 7B). Our synthetic sequence commenced by the addition of 3‐butenyl Grignard to 2‐oxindole 12 (see Scheme S9, S.I.…”

Photoredox/Cu‐Catalyzed Decarboxylative C(sp3)−C(sp3) Coupling to Access C(sp3)‐Rich gem‐Diborylalkanes

“…Specifically, β-tertiary gem-diborylalkane products (39-42) derived from bulky Gemfibrozil, Enoxolone, Oleanolic acid, and Betulinic acid, respectively, were synthesized in good to excellent yields as a single isomer. Additionally, other benzylic or linear drugs (43)(44)(45)(46)(47) and natural products (48,49) bearing functionalities such as ethers (45,47), ketones (45,46), and olefins (48,49) were tolerant to the reaction conditions. Several heterocyclebearing drug molecules, including Isoxepac, Tolmetin, Oxaprozin, Indomethacin, and Gabapentin derivatives, some of which contain basic nitrogens, were effectively gemdiborylmethylated (45, 50-53).…”