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The construction of an all‐in‐one catalyst, in which the photosensitizer and the transition metal site are close to each other, is important for improving the efficiency of metallaphotoredox catalysis. However, the development of convenient synthetic strategies for the precise construction of an all‐in‐one catalyst remains a challenging task due to the requirement of precise installation of the catalytic sites. Herein, we have successfully established a facile bottom‐up strategy for the direct synthesis of Ni(II)‐incorporated covalent organic framework (COF), named LZU‐713@Ni, as a versatile all‐in‐one metallaphotoredox catalyst. LZU‐713@Ni showed excellent activity and recyclability in the photoredox/nickel‐catalyzed C−O, C−S, and C−P cross‐coupling reactions. Notably, this catalyst displayed a better catalytic activity than its homogeneous analogues, physically mixed dual catalyst system, and, especially, LZU‐713/Ni which was prepared through post‐synthetic modification. The improved catalytic efficiency of LZU‐713@Ni should be attributed to the implementation of bottom‐up strategy, which incorporated the fixed, ordered, and abundant catalytic sites into its framework. This work sheds new light on the exploration of concise and effective strategies for the construction of multifunctional COF‐based photocatalysts. [ABSTRACT FROM AUTHOR]

A visible‐light‐driven and room temperature photo‐Wolff‐Kischner reaction of sulfur ylides and N‐tosylhydrazones has been developed for the first time to provide modular access to alkene synthesis. The high functional group tolerance and broad substrate scope were demonstrated by more than 60 examples. Both E‐ and Z‐olefinic stereochemistry in the products could be controlled with excellent stereoselectivity. A series of mechanistic studies support that the reaction should proceed through a radical‐carbanion crossover pathway, specifically involving addition of photo‐generated sulfur ylide radical cations to N‐tosylhydrazones to form carbanions and subsequent Wolff‐Kischner process. [ABSTRACT FROM AUTHOR]

A catalytic asymmetric [3+2] cycloaddition reaction of chiral palladium-containing N1-1,3-dipoles with methyleneindolinones has been successfully developed. The reaction allows an efficient construction of 3,3′-pyrrolinyl spirooxindoles with high yields and excellent stereoselectivities (up to 93 % yield, 19:1 d.r. and >99 % ee). A synthetic application of this methodology is demonstrated and a stereocontrol mechanism is proposed. [ABSTRACT FROM AUTHOR]

Photocatalysis enables the cascade reactions of indoles and CBr4 in MeOH through a C(sp2)H functionalization/methanolysis sequence. The title reaction provides an efficient access to indole 2- and 3-carboxylates in a single operation (no preinstallation of protecting as well as directing groups was required) with good yields under mild reaction conditions. [ABSTRACT FROM AUTHOR]

An unprecedented Zn(OTf)2-catalyzed asymmetric Michael addition/cyclization cascade of 3-nitro-2 H-chromenes with 3-isothiocyanato oxindoles has been disclosed. This transformation provides an efficient access to various synthetically important polycyclic spirooxindoles in a highly stereoselective manner under mild conditions (72-99 % yields, up to >95:5 d.r. and >99 % ee). The reaction leads to the formation of three consecutive stereocenters, including 1,3-nonadjacent tetrasubstituted carbon stereocenters, in a single operation. A bifunctional activation model of the chiral Zn(OTf)2/bis(oxazoline) complex was proposed based on control experiments, wherein the ZnII moiety serves as a Lewis acid and the N atom of the free NH group acts as a Lewis base by a hydrogen-bonding interaction. [ABSTRACT FROM AUTHOR]

Get asymmetric! Asymmetric [4+1] annulation of sulfur ylides and N‐(ortho‐chloromethyl)aryl amides allowed the formation of the desired cycloadduct with moderate to high yields and enantioselectivities (see scheme). The described strategy, taking advantage of chiral sulfur ylides, represents a direct procedure to access chiral 2‐substituted indolines. [ABSTRACT FROM AUTHOR]