{'fraction_non_alphanumeric': 0.028484231943031537, 'fraction_numerical': 0.011190233977619531, 'mean_word_length': 6.454545454545454, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Catalytic Benzannulation Reactions of Enynones for Accessing Heterocycle-Incorporating Diarylmethanes

Two catalytic benzannulation-1,4-addition cascade of available enynones with indoles and tetronic acid-derived enamino lactones as the C-nucleophiles are reported, producing 53 examples of heterocycle-incorporating diarylmethanes with moderate to excellent yields. The combination of AgOTf and Sc(OTf)3 enables the bimetallic synergistic catalysis of enynones and indoles to access 35 triarylmethanes with generally good yields in which in-situ-generation of ortho-naphthoquinone methides (o-NQMs) were the key intermediates. Exchanging indoles for tetronic acid-derived enaminolactones resulted in 18 diarylmethanes by Ag-catalyzed benzannulation-1,4-addition cascade. Both reactions are advantageous for their high atom-utilization and mild reaction conditions, providing intriguing complementary approaches for the direct synthesis of new heterocycle-containing diarylmethanes.