{'fraction_non_alphanumeric': 0.026923076923076925, 'fraction_numerical': 0.007692307692307693, 'mean_word_length': 5.911504424778761, '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}}
Stereodivergent Synthesis of α-Quaternary Serine and Cysteine Derivatives Containing Two Contiguous Stereogenic Centers via Synergistic Cu/Ir Catalysis.

A stereodivergent preparation of α-quaternary serine/cysteine derivatives incorporating two adjacent stereogenic centers has been developed through Cu/Ir-catalyzed asymmetric allylation of 2-oxazoline-4-carboxylates and 2-thiazoline-4-carboxylates. Tuning the electronic effect is the key to enhancing the reactivity of 2-oxazoline-4-carboxylates and suppressing the undesired β-elimination. The salient feature of this protocol is that all four stereoisomers of α-quaternary serine and cysteine derivatives could be achieved from the identical starting materials through pairwise combination of two distinct chiral catalysts.