Silicon‐containing compounds are widely used as synthetic building blocks, functional materials, and bioactive reagents. In particular, silyl radicals are important intermediates for the synthesis and transformation of organosilicon compounds. Herein, we describe the first protocol for the generation of silyl radicals by photoinduced decarboxylation of silacarboxylic acids, which can be easily prepared in high yield on a gram scale and are very stable to air and moisture. Irradiation of silacarboxylic acids with blue LEDs (455 nm) in the presence of a commercially available photocatalyst releases silyl radicals, which can further react with various alkenes to give the corresponding silylated products in good‐to‐high yields with broad functional‐group compatibility. This reaction proceeds in the presence of water, enabling efficient deuterosilylation of alkenes with D2O as the deuterium source. Germyl radicals were similarly obtained.

Herein we report av ersatile Mizoroki-Heck-type photoinducedC (sp 3 )ÀNb ond cleavage reaction. Under visible-light irradiation (455 nm, blue LEDs) at room temperature, alkyl Katritzkys alts react smoothly with alkenes in a1 :1 molar ratio in the presence of 1.0 mol %o fc ommercially available photoredoxc atalyst without the need for any base, affording the correspondingalkyl-substituted alkenesi ng ood yields with broad functional-groupc ompatibility.N otably,t he E/Z-selectivity of the alkene products can be controlled by an appropriate choice of photoredox catalyst.Alkenesa re essential building blocks for organic synthesis, and are ubiquitous in the fields of life science, drug discovery,a nd materials science.T he different configurational isomers (E and Z)o fa lkenes usually display distinct physicochemical properties and physiological activities, [1] and so stereoselective synthesis of alkenes has long been of great interest to synthetic chemists. Currently,t he Mizoroki-Heck (MÀH) reaction, [2] which is aP d-catalyzedc ross-coupling reactionb etween alkenes and aryl/vinyl halides, is regarded as one of the most useful protocols for the selective synthesis of substituted alkenes. [3] However,d espite the high efficiency and applicability of the Pd-catalyzed reaction, it has some limitations.F or example, methodology for cross-couplingb yu sing aliphatic halides, especially those possessingab-hydrogen atom, is still limited due to the occurrence of rapid b-H elimination as as ide reaction. Further,t he configuration of the formed C=Cb ond is determined by the transition structure at the syn-extrusions tep (periplanar ÀPdÀCÀCÀHÀ 4-membered ring), and hence external control of the E/Z selectivityb yc hanging the catalysto r ligand is difficult.T hus, althoughe legante xamples of the Pdcatalyzed reactioni nvolving alkyl halides have been report-

π-Conjugated polymers are widely used in optoelectronics for fabrication of organic photovoltaic devices, organic light-emitting diodes, organic field effect transistors, and so on. Here we describe the protocol for polycondensation of bifunctional aryl ethers or aryl ammonium salts with aromatic dimetallic compounds through cleavage of inert C–O/C–N bonds. This reaction proceeds smoothly in the presence of commercially available Ni/Pd catalyst under mild conditions, affording the corresponding π-conjugated polymers with high molecular weight. The method is applicable to monomers that are unreactive in other currently employed polymerization procedures, and opens up the possibility of transforming a range of naturally abundant chemicals into useful functional compounds/polymers.

Copper-catalyzed stereospecific cross-couplings of boronic esters are reported. Boron “ate” complexes derived from pinacol boronic esters and tert-butyl lithium undergo stereospecific transmetalation to copper cyanide, followed by coupling with alkynyl bromides, allyl halides, propargylic halides, β-haloenones, hydroxylamine esters, and acyl chlorides. Through this simple transformation, commercially available inexpensive compounds can be employed to convert primary and secondary alkylboronic esters to a wide array of synthetically useful compounds.

A neighboring boronate group in the substrate provides a dramatic rate acceleration in transmetalation to copper and thereby enables organoboronic esters to participate in unprecedented site-selective cross-couplings. This cross-coupling operates under practical experimental conditions and allows for coupling between vicinal bis­(boronic esters) and allyl, alkynyl, and propargyl electrophiles as well as a simple proton. Because the reactive substrates are vicinal bis­(boronic esters), the cross-coupling described herein provides an expedient new method for the construction of boron-containing reaction products from alkenes. Mechanistic experiments suggest that chelated cyclic ate complexes may play a role in the transmetalation.