Chiral α-aryl N-heterocycles are commonly found in natural products, pharmaceutical agents, and chiral catalysts but remain challenging to access via asymmetric catalysis. Herein, we report a general and modular approach for the direct enantioselective α-arylation of saturated azacycles and acyclic N-alkyl benzamides via nickel/photoredox dual catalysis. This process exploits the hydrogen atom transfer ability of photoeliminated chlorine radicals to convert azacycles to the corresponding α-amino alkyl radicals that then are coupled with ubiquitous and inexpensive (hetero)aryl chlorides. These coupling reactions require no oxidants or organometallic reagents, feature feedstock starting materials, a broad substrate scope, and high enantioselectivities, and are applicable to late-stage diversification of medicinally relevant complex molecules. Mechanistic studies suggest that the nickel catalyst uncommonly plays multiple roles, accomplishing chlorine radical generation, α-amino radical capture, cross-coupling, and asymmetric induction.
Forty-three new species of Nesticidae are described from China, Indonesia, Philippines, Singapore, Thailand, Vietnam and Madagascar, and two new junior synonyms are suggested. A new genus, Speleoticus gen. n., is described with Nesticus navicellatus Liu & Li, 2013 as the type species, and four species are transferfed from Nesticus, i.e., Speleoticus globosus (Liu & Li, 2013), comb. n., Speleoticus libo (Chen & Zhu, 2005), comb. n., Speleoticus navicellatus (Liu & Li, 2015), comb. n. and Speleoticus uenoi (Yaginuma, 1972), comb. n. The new species described in this paper belong to four genera and are: Hamus cornutus sp. n. (♂♀), Hamus kangdingensis sp. n. (♂), Hamus luzon sp. n. (♀), Hamus mangunensis sp. n. (♂), Nescina kohi sp. n. (♂♀), Nesticella baiseensis sp. n. (♂♀), Nesticella baobab sp. n. (♂), Nesticella caeca sp. n. (♂♀), Nesticella chongqing sp. n. (♀), Nesticella dazhuangensis sp. n. (♂♀), Nesticella fuliangensis sp. n. (♂♀), Nesticella gazuida sp. n. (♀), Nesticella gongshanensis sp. n. (♀), Nesticella griswoldi sp. n. (♂♀), Nesticella hongheensis sp. n. (♂♀), Nesticella huomachongensis sp. n. (♂♀), Nesticella jingpo sp. n. (♀), Nesticella kaohsiungensis sp. n. (♂♀), Nesticella lisu sp. n. (♂♀), Nesticella liuzhaiensis sp. n. (♀), Nesticella nandanensis sp. n. (♂♀), Nesticella phami sp. n. (♂♀), Nesticella potala sp. n. (♀), Nesticella qiaoqiensis sp. n. (♀), Nesticella qiongensis sp. n. (♂♀), Nesticella robusta sp. n. (♂♀), Nesticella rongtangensis sp. n. (♂), Nesticella sanchaheensis sp. n. (♂♀), Nesticella sulawesi sp. n. (♀), Nesticella sumatrana sp. n. (♂), Nesticella tibetana sp. n. (♂♀), Nesticella vanlang sp. n. (♀), Nesticella wanzaiensis sp. n. (♂♀), Nesticella xiongmao sp. n. (♂♀), Nesticella xixia sp. n. (♂♀), Nesticella yanbeiensis sp. n. (♂♀), Nesticella yao sp. n. (♀), Nesticella zhiyuani sp. n. (♂♀), Pseudonesticus dafangensis sp. n. (♂♀), Pseudonesticus miao sp. n. (♂♀), Pseudonesticus spinosus sp. n. (♂♀), Pseudonesticus wumengensis sp. n. (♀), Pseudonesticus ziyunensis sp. n. (♂♀). Nesticella inthanoni (Lehtinen & Saaristo, 1980), syn. n. is synonymised with Nesticella mollicula (Thorell, 1898); Nesticella taiwan Tso & Yoshida, 2000, syn. n. is synonymised with Nesticella odonta (Chen, 1984). The female of Nesticella connectens Wunderlich, 1995, so far unknown, is described and recorded from Thailand. Nesticidae are reported from Madagascar for the first time. Nesticella nepalensis (Hubert, 1973) is recorded for the first time from China. Types of Nesticella odonta (Chen, 1984), Nesticella songi Chen & Zhu, 2004 and Nesticella yui Wunderlich & Song, 1995 are re-examined and photographed. The entire genus Nesticella is reviewed, and four species groups are recognised. DNA barcodes of the new species are obtained to confirm their correct identifications.
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