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The synthesis of stereochemically complex molecules in the pharmaceutical and agrochemical industries requires precise control over each distinct stereocenter, a feat that can be challenging and time consuming using traditional asymmetric synthesis. Although stereoconvergent processes have the potential to streamline and simplify synthetic routes, they are currently limited by a narrow scope of inducibly dynamic stereocenters that can be readily epimerized. Here, we report the use of photoredox catalysis to enable the racemization of traditionally static, unreactive stereocenters through the intermediacy of prochiral radical species. This technology was applied in conjunction with biocatalysts such as ketoreductases and aminotransferases to realize stereoconvergent syntheses of stereodefined γ-substituted alcohols and amines from β-substituted ketones.

α‐Silylalkylamines and α‐borylalkylamines are versatile synthetic intermediates and attractive scaffolds found in pharmaceutical drugs and agrochemicals. Despite great progress on synthetic methods for preparation of α‐silylalkylamines or α‐borylalkylamines, there are no general strategies for preparation of α‐boryl‐α‐silylalkylamines and the reactivity has not been explored. Here we report deoxygenative geminal silylboration of amides using silylboronates in the presence of alkoxide base catalyst, producing α‐boryl‐α‐silylalkylamines. The silicon and boron groups in α‐boryl‐α‐silylalkylamines are found to be utilized to chemoselective transformations, such as protonation and alkylation. This protocol serves various α‐silylalkylamines and α‐borylalkylamines from readily available amides. [ABSTRACT FROM AUTHOR]

A quadruple N‐heterocyclic carbene/cobalt/photoredox/Brønsted base catalysis to realize branch‐selective hydroacylation of styrenes with aromatic and aliphatic aldehydes is demonstrated. This protocol allows access to branched ketones from readily available materials in an atom‐economical manner. The quadruple catalysis can transfer a formyl hydrogen of aldehydes as a hydrogen radical equivalent onto the terminal carbon of an alkene by controlled electron and proton transfers. [ABSTRACT FROM AUTHOR]

A catalytic reductive cross‐coupling between arylaldehydes and aryl electrophiles using a silylboronate as a terminal reductant is described. The reaction involves a copper‐catalyzed silylboration of aldehydes affording the O‐borylated α‐silyl alcohols followed by a nucleophilic aromatic substitution reaction with aryl electrophiles. This protocol offers a new opportunity to access 1,1‐diarylmethanol derivatives without rare metals or highly basic organometallic reagents. [ABSTRACT FROM AUTHOR]

We developed an organophotoredox‐catalyzed reaction for N‐alkylation of sulfonamides with aliphatic carboxylic acid‐derived redox active esters as alkylating reagents. Under mild and transition metal‐free conditions, a series of functionalized N‐alkylated sulfonamides were prepared. This protocol also enabled the functionalization of pharmaceutical drugs bearing a sulfonamide or carboxylic acid moiety. This radical‐mediated process allowed the assembly of three components including sulfonamides, redox active esters, and alkenes to yield complex sulfonamides in a one‐pot manner. [ABSTRACT FROM AUTHOR]

A reductive cross‐coupling reaction between aromatic aldehydes and arylnitriles using a copper catalyst and a silylboronate as a reductant is reported. This protocol represents an unprecedented approach to the chemoselective synthesis of α‐hydroxy ketones by electrophile–electrophile cross‐coupling. [ABSTRACT FROM AUTHOR]

The transition‐metal‐free cross‐coupling of alkyl or aryl electrophiles by using tertiary benzylic organoboronates is reported. This reaction involves the generation of tertiary alkyl anions from organoboronates in the presence of an alkoxide base and then their substitution reactions. This protocol allows the simple and efficient construction of quaternary carbon centers. [ABSTRACT FROM AUTHOR]

In this communication, we report a chiral copper/NHC-catalyzed reaction between aromatic aldehydes and propargylic phosphates using a silylboronate, providing enantioenriched chiral α-allenic alcohols with complete regioselectivity and moderate to high enantioselectivity. The reaction pathway involves the catalytic formation of a nucleophilic α-alkoxylalkylcopper(I) species from aldehydes followed by its SN2′ type substitution reaction with propargylic phosphates. [ABSTRACT FROM AUTHOR]

Dehydrative allylation between widely available aldehydes and allylic alcohols to afford β,γ‐unsaturated ketones was enabled by a synergistic merger of a thiazolium N‐heterocyclic carbene catalyst and a palladium‐bisphosphine catalyst. Dehydrative allylation between widely available aldehydes and allylic alcohols to afford β,γ‐unsaturated ketones was enabled by a synergistic merger of a thiazolium N‐heterocyclic carbene catalyst and a palladium‐bisphosphine catalyst. [ABSTRACT FROM AUTHOR]

Abstract: Trialkylphosphine organocatalysis has enabled the regioselective anti‐carboboration of alkynoates with 9‐BBN‐based 1,1‐diborylalkanes to produce secondary allylboranes with β‐alkoxycarbonyl and γ‐boryl substituents. The utility of the densely functionalized allylboranes was demonstrated by the highly diastereoselective allylation of N‐(trimethylsilyl)aldimines to produce homoallylamines containing tertiary allylborane and acrylate moieties. [ABSTRACT FROM AUTHOR]

A synergistic action of a thiazolium N‐heterocyclic carbene catalyst and a palladium–bisphosphine catalyst has enabled the allylation between aldehydes acyl anions and allylic amines to afford β,γ‐unsaturated ketones, which are versatile synthetic intermediates for organic synthesis. [ABSTRACT FROM AUTHOR]

A method for the synthesis of 1,1-diborylalkenes through a Brønsted base catalyzed reaction between terminal alkynes and bis(pinacolato)diboron has been developed. The procedure allows direct synthesis of functionalized 1,1-diborylalkenes from various terminal alkynes including propiolates, propiolamides, and 2-ethynylazoles. [ABSTRACT FROM AUTHOR]

The scope of the copper-catalyzed coupling reactions between organoboron compounds and allylic phosphates is expanded significantly by employing triphenylphosphine as a ligand for copper, allowing the use of secondary alkylboron compounds. The reaction proceeds with complete γ- E-selectivity and preferential 1,3- syn stereoselectivity. The reaction of γ-silicon-substituted allylic phosphates affords enantioenriched α-stereogenic allylsilanes. [ABSTRACT FROM AUTHOR]

A versatile route to trisubstituted alkenylstannanes is presented. The alkyl and Sn moieties were introduced at the β and α carbon atoms of alkynoates, respectively, in a formal syn addition mode with complete regioselectivity (see scheme). A variety of functional groups were tolerated in the alkylboranes and alkynoates. [ABSTRACT FROM AUTHOR]

The stereochemical courses of the copper-catalyzed allyl-alkyl coupling between enantioenriched chiral allylic phosphates and alkylboranes were switchable between 1,3-anti and 1,3-syn selectivities by the choice of solvents and achiral alkoxide bases with different steric demands. The reactions with γ-silylated allylic phosphates allow efficient synthesis of enantioenriched chiral allylsilanes with tertiary or quaternary carbon stereogenic centers. Cyclic and acycic bimodal participation of alkoxyborane species in an organocopper addition-elimination sequence is proposed to account for the phenomenon of the anti/syn-stereochemical reversal. [ABSTRACT FROM AUTHOR]

A copper-catalyzed γ-selective allyl-alkyl coupling between γ-silylated allylic phosphates and alkylboron compounds (alkyl- 9-BBN, prepared by hydroboration of alkenes with 9-BBN-H) produced allylsilanes. The reaction tolerated various functional groups in both the alkylboranes and the allylic phosphates, and afforded functionalized allylsilanes. [ABSTRACT FROM AUTHOR]

Synergistic cooperation of thiazolium N‐heterocyclic carbene catalyst and a palladium catalyst enabled the dehydrative direct allylation between aldehydes and allylic alcohols to produce β,γ‐unsaturated ketones. The cover picture depicts a similar relationship between anemone fish and sea anemone living cooperatively in their natural environment. More information can be found in the Communication by H. Ohmiya et al. on page 724. [ABSTRACT FROM AUTHOR]

leading to acrylonitrile derivatives with a tetrasubstituted alkene moiety [ABSTRACT FROM AUTHOR]

An abstract of the article "Synthesis of 1,1-Diborylalkenes Through a Broensted Base Catalyzed Reaction Between Terminal Alkynes and Bis(pinacolato)diboron" by Akira Morinaga, Kazunori Nagao and Hirohisa Ohmiya.

An abstract of the study "Copper-Catalyzed Stereoselective Conjugate Addition of Alkylboranes to Alkynoates" by K. Nagao and colleagues is presented.

Utilisation of triphenylphosphine as a ligand allows for the coupling of alkyl-9-BBN derivatives with a variety of silicon- and non-silicon-containing cyclic and acyclic allylic (Z)-phosphates. [ABSTRACT FROM AUTHOR]

The title reaction is applied to various terminal alkenes endowed with a primary or a secondary alcohol functionality affording five- or six-membered ring ethers. [ABSTRACT FROM AUTHOR]

The formed E-borylsilyl olefines are further functionalized by palladium catalyzed coupling reactions. [ABSTRACT FROM AUTHOR]

The transformation of the 2-tolyl substituted analogue of the phenyl alkynoate (III) requires 100 °C to provide a moderate yield of the corresponding sterically congested alkylborane. [ABSTRACT FROM AUTHOR]

The reaction of monosubstituted ethenes with (9-BBN)2 and subsequent Cu-catalyzed coupling of the resulting alkylborane with acetylenic esters and Bu3SnOMe offers a stereoselective synthesis of highly functionalized vinyl stannanes. [ABSTRACT FROM AUTHOR]

The new title coupling reaction is successfully exemplified by Z-, e.g. (I) and (IV), and E-allylsilanes (VI) and non-silicon-substituted allylic phosphates (VIII). [ABSTRACT FROM AUTHOR]