Fluoroalkylacylsilanes as Novel Ambiphilic Donor–Acceptor Carbene Precursors DOI
Xiao Shen

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: April 25, 2025

ConspectusCarbenes, as highly reactive intermediates, have emerged pivotal tools in organic synthesis, catalysis, and materials science due to their versatile reactivity broad applicability. Among the diverse classes of carbenes, donor-acceptor carbenes (DACs) attracted significant attention owing unique electronic properties exceptional reaction selectivity. The distinctive DACs arises from synergistic interplay between electron-withdrawing electron-donating groups attached carbene center, enabling a wide array transformations. These attributes established indispensable building blocks for constructing complex molecular architectures achieving precise control over chemical transformation.This Account highlights our recent advancements development fluoroalkylacylsilanes novel precursors DACs. Under photocatalytic conditions, these generate fluoroalkyl siloxycarbenes via radical Brook rearrangement. group, known its strong properties, imparts electrophilic characteristics, while siloxyl group stabilizes center. Together, functionalities render ideal candidates generation DACs, providing platform range transformations, including cycloadditions, bond insertions, construction new structures.First, we developed visible-light-induced, organocatalyzed [2 + 1] cyclization alkynes trifluoroacetylsilanes, leading synthesis cyclopropenols. Mechanistic studies provided compelling evidence involvement triplet intermediates this reaction, demonstrating utility functionalized cyclic compounds. Second, explored cyclopropanation reactions elucidated diastereoselective transfer trifluoroacetylsilane-derived alkenes. Density functional theory (DFT) calculations revealed key insights into origins observed diastereoselectivity, offering molecular-level understanding stereochemical outcomes. Additionally, extended scope include organoboronic esters, divergent ketones. By modulating situ-generated organoboronate complexes─formed through with esters─we achieved selective both fluorine-maintaining defluorinated This transition-metal-free approach is operationally simple compatible substrates, aryl, alkenyl, alkyl boronic esters. Beyond C-B functionalization, applied C(sp2)-H functionalization 1,3-azoles. investigations suggest that success stems dual role trifluoroacetylsilanes under conditions: they not only participate but also produce biradicals facilitate ring-opening aromatization fused cyclopropanes.We anticipate work on ambiphilic will lay groundwork further use acylsilanes chemistry. developments are expected inspire strategies design expand silanes synthetic opening avenues intricate architectures.

Language: Английский

Asymmetric Trapping of Siloxyketenes In Situ Generated from [1,3]-Silyl Migration of α-Ketoacylsilanes: A Visible-Light-Driven Palladium-Catalyzed [4 + 2] Cycloaddition DOI
Lingyun Yao, Xinlan Zou, Jian Zhang

et al.

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 5796 - 5805

Published: March 25, 2025

The transition metal-catalyzed asymmetric [n + 2] cycloaddition reaction with oxy-substituted ketene intermediates remains a synthetic challenge due to the limited availability of suitable precursors. Herein, we report visible-light-driven, palladium-catalyzed [4 vinyl benzoxazinanones siloxyketene intermediates, generating structurally diverse chiral quinolinone derivatives satisfactory diastereo- and enantioselectivities. transient generation siloxyketenes from α-ketoacylsilylanes through visible-light-induced Brook rearrangement is important for success present cycloaddition. 13C-labeling experiments reveal pathway involving [1,3]-silyl migration process. side arm effects BOX ligand silyl steric hindrance α-ketoacylsilanes play crucial roles in stereoselectivity control, theoretical calculations provide insights into stereochemical outcome reaction.

Language: Английский

Citations

0
Fluoroalkylacylsilanes as Novel Ambiphilic Donor–Acceptor Carbene Precursors DOI
Xiao Shen

Accounts of Chemical Research, Journal Year: 2025, Volume and Issue: unknown

Published: April 25, 2025

ConspectusCarbenes, as highly reactive intermediates, have emerged pivotal tools in organic synthesis, catalysis, and materials science due to their versatile reactivity broad applicability. Among the diverse classes of carbenes, donor-acceptor carbenes (DACs) attracted significant attention owing unique electronic properties exceptional reaction selectivity. The distinctive DACs arises from synergistic interplay between electron-withdrawing electron-donating groups attached carbene center, enabling a wide array transformations. These attributes established indispensable building blocks for constructing complex molecular architectures achieving precise control over chemical transformation.This Account highlights our recent advancements development fluoroalkylacylsilanes novel precursors DACs. Under photocatalytic conditions, these generate fluoroalkyl siloxycarbenes via radical Brook rearrangement. group, known its strong properties, imparts electrophilic characteristics, while siloxyl group stabilizes center. Together, functionalities render ideal candidates generation DACs, providing platform range transformations, including cycloadditions, bond insertions, construction new structures.First, we developed visible-light-induced, organocatalyzed [2 + 1] cyclization alkynes trifluoroacetylsilanes, leading synthesis cyclopropenols. Mechanistic studies provided compelling evidence involvement triplet intermediates this reaction, demonstrating utility functionalized cyclic compounds. Second, explored cyclopropanation reactions elucidated diastereoselective transfer trifluoroacetylsilane-derived alkenes. Density functional theory (DFT) calculations revealed key insights into origins observed diastereoselectivity, offering molecular-level understanding stereochemical outcomes. Additionally, extended scope include organoboronic esters, divergent ketones. By modulating situ-generated organoboronate complexes─formed through with esters─we achieved selective both fluorine-maintaining defluorinated This transition-metal-free approach is operationally simple compatible substrates, aryl, alkenyl, alkyl boronic esters. Beyond C-B functionalization, applied C(sp2)-H functionalization 1,3-azoles. investigations suggest that success stems dual role trifluoroacetylsilanes under conditions: they not only participate but also produce biradicals facilitate ring-opening aromatization fused cyclopropanes.We anticipate work on ambiphilic will lay groundwork further use acylsilanes chemistry. developments are expected inspire strategies design expand silanes synthetic opening avenues intricate architectures.

Language: Английский

Citations

0