Nucleophilic chiral phosphine catalysis has been prosperous in asymmetric synthesis over the past two decades. Various tunable chiral phosphines display excellent activity and selectivity in asymmetric transformations...Nucleophilic chiral phosphine catalysis has been prosperous in asymmetric synthesis over the past two decades. Various tunable chiral phosphines display excellent activity and selectivity in asymmetric transformations including acycloaddition reactions and cycloaddition reactions. Enantiomerically enriched cyclic compounds are ubiquitous in natural products and drug molecules. These phosphinecatalyzed reactions provide effective and extensive strategies for the synthesis of a series of complex cyclic compounds as well as the synthesis of chiral compounds which could be easily transformed to carbocycles and heterocycles. This minireview summarizes recent developments in this area and highlights meaningful breakthroughs.展开更多
The hydroxyl group of carbocyclic nucleosides was inversed when the compounds were treated with Me3SiCl, KCN and a catalytic mount of NaI in DMF/CH3CN.
Enantiomerically enriched (R)-1-(2-bromocycloalkenyl)-3-buten-1-ol and its derivatives were obtained via enantioselective hydrolysis [resolution] with good enantioselectivities (E = 31 to >500) using Candida paraps...Enantiomerically enriched (R)-1-(2-bromocycloalkenyl)-3-buten-1-ol and its derivatives were obtained via enantioselective hydrolysis [resolution] with good enantioselectivities (E = 31 to >500) using Candida parapsilosis ATCC 7330. The various reaction parameters were optimized for enantioselective hydrolysis to achieve high enantiomeric excess (ee) and conversions. Among the substrates tested, (RS)-1-(2-bromocyclohex-1-en-1-yl) but-3-yn-1-yl acetate was hydrolysed by the biocatalyst in 12 h to the corresponding (R)-alcohol in 49% conversion and >99 ee. The optically pure allylic alcohol thus obtained was used as a chiral starting material for the synthesis of an enantiomerically enriched bicyclic alcohol effectively establishing achemoenzymatic route.展开更多
A Rh(III)-catalyzed,transmetalation triggered C—H activation/annulation of 2-biphenylboronic acids with diazo compounds fromβ-keto esters or 1,3-dicarboxylates has been developed,leading to the synthesis of two kind...A Rh(III)-catalyzed,transmetalation triggered C—H activation/annulation of 2-biphenylboronic acids with diazo compounds fromβ-keto esters or 1,3-dicarboxylates has been developed,leading to the synthesis of two kinds of 9,10-phenanthrenes.Notably,a rhodacyle was synthesized by treating the rhodium catalyst with stoichiometric amounts of 2-biphenylboronic acids and pyridine,which was further verified to be active for the catalytic system.The reactions proceeded under redox-neutral and air-tolerant conditions to produce a series of all-carbon six-membered rings with high efficiency.展开更多
Yne-allenes bearing both a C-C triple bond and an allene unit are a class of focal substrates in organic synthesis,in view of their structure diversity,.high reactivity and intermediate variety in the past years.Engag...Yne-allenes bearing both a C-C triple bond and an allene unit are a class of focal substrates in organic synthesis,in view of their structure diversity,.high reactivity and intermediate variety in the past years.Engaging yne-allenes in numerous annulation cascades provides efficient and direct accesses to elaborate functionalized polycyclic molecular architectures in a convergent manner.There are lots of types of catalytic chemical reactions such as intramolecular cyclizations,cycloisomerizations,intermolecular annulations,and bicyclizations as well as tricyclizations with the assistance of Lewis acids,Bronsted acids,bases,transition metals,and otherr c atalysts.This review provides an overview of the chemistry developed with transformations of yne-allenes by discussing their general and specific reactivities,presenting and commenting on their mechanisms as well as their applications.展开更多
Although the NHC-catalyzed cyclization reactions have been well established for the synthesis of various heterocycles,the corresponding all carbon cyclization reaction for the synthesis of carbocycles is far less esta...Although the NHC-catalyzed cyclization reactions have been well established for the synthesis of various heterocycles,the corresponding all carbon cyclization reaction for the synthesis of carbocycles is far less established.In this note,the NHC-catalyzed all carbon[4+2]cyclocondensation of α,β-unsaturated acyl chlorides and 3-alkenyloxindoles was developed to give the corresponding spirocarbocyclic oxindoles in good yield with good to high diastereoselectivities.展开更多
Molecular scaffolds endowed with all-carbon quaternary stereocenter are ubiquitous in natural products and significant bioactive molecules.However,efficient construction of this type of structure units is full of chal...Molecular scaffolds endowed with all-carbon quaternary stereocenter are ubiquitous in natural products and significant bioactive molecules.However,efficient construction of this type of structure units is full of challenge due to their congested chemical envi-ronment.Herein,we report a new gold(Ⅰ)self-relay catalysis merging[3,3]-sigmatropic rearrangement/Nazarov cyclization with al-lylic alkylation starting from 1,3-enyne acetates and allylic alcohols,producing a wide range of synthetically important allyl cyclo-pentenones with an all-carbon quaternary stereocenter in good yields under mild conditions.This protocol demonstrates the precise control of regioselectivity,high functional group tolerance of substrates and the low loading of gold catalyst without inert atmos-phere protection,providing a catalytic and efficient entry to all-carbon quaternary stereocenters.展开更多
Nucleoside analogues show a variety of biological activities. To prepare new purine nucleoside analogues that could inhibit the proliferation of tumor cells and resist enzyrne hydrolysis, we designed and synthesized 1...Nucleoside analogues show a variety of biological activities. To prepare new purine nucleoside analogues that could inhibit the proliferation of tumor cells and resist enzyrne hydrolysis, we designed and synthesized 15 different L-5＇noraristeromycin analogues, in which thioether, sulfoxide or sulfone function was introduced to replace the 5＇-hydroxymethyl group. Their anti-tumor activities were assayed in vitro. One compound showed potent anti-tumor activity.展开更多
Concise and efficient three-component domino [4＋ 1 ＋ 1] carbocyclization to highly substituted fluoren-9-one derivatives promoted by K2CO3 has been developed under microwave irradiation conditions. The direct bis-cy...Concise and efficient three-component domino [4＋ 1 ＋ 1] carbocyclization to highly substituted fluoren-9-one derivatives promoted by K2CO3 has been developed under microwave irradiation conditions. The direct bis-cyanation and aryl amination residing in fluoren-9-one framework were achieved in a one-pot operation. The reaction proceeds at fast rates and can be finished within 30 min, which makes workup convenient to give good to excellent chemical yields.展开更多
基金financial support from the National Basic Research Program of China(973 Project,No.2015CB856603)the National Natural Science Foundation of China(Nos.20472096,21372241,21361140350,20672127,21421091,21372250,21121062,21302203,20732008 and 21572052)
文摘Nucleophilic chiral phosphine catalysis has been prosperous in asymmetric synthesis over the past two decades. Various tunable chiral phosphines display excellent activity and selectivity in asymmetric transformations including acycloaddition reactions and cycloaddition reactions. Enantiomerically enriched cyclic compounds are ubiquitous in natural products and drug molecules. These phosphinecatalyzed reactions provide effective and extensive strategies for the synthesis of a series of complex cyclic compounds as well as the synthesis of chiral compounds which could be easily transformed to carbocycles and heterocycles. This minireview summarizes recent developments in this area and highlights meaningful breakthroughs.
文摘The hydroxyl group of carbocyclic nucleosides was inversed when the compounds were treated with Me3SiCl, KCN and a catalytic mount of NaI in DMF/CH3CN.
文摘Enantiomerically enriched (R)-1-(2-bromocycloalkenyl)-3-buten-1-ol and its derivatives were obtained via enantioselective hydrolysis [resolution] with good enantioselectivities (E = 31 to >500) using Candida parapsilosis ATCC 7330. The various reaction parameters were optimized for enantioselective hydrolysis to achieve high enantiomeric excess (ee) and conversions. Among the substrates tested, (RS)-1-(2-bromocyclohex-1-en-1-yl) but-3-yn-1-yl acetate was hydrolysed by the biocatalyst in 12 h to the corresponding (R)-alcohol in 49% conversion and >99 ee. The optically pure allylic alcohol thus obtained was used as a chiral starting material for the synthesis of an enantiomerically enriched bicyclic alcohol effectively establishing achemoenzymatic route.
基金the financial support for this work from the National Key R&D Program of China(2021YFC0864700)the NSFC(Nos.21801066,U1804283 and 82130103)+2 种基金the Central Plains Scholars and Scientists Studio Fund(2018002)the project funded by the Natural Science Foundation of Henan Province(222300420056,222300420204)the China Postdoctoral Science Foundation(2020M682307,2021T140183).
文摘A Rh(III)-catalyzed,transmetalation triggered C—H activation/annulation of 2-biphenylboronic acids with diazo compounds fromβ-keto esters or 1,3-dicarboxylates has been developed,leading to the synthesis of two kinds of 9,10-phenanthrenes.Notably,a rhodacyle was synthesized by treating the rhodium catalyst with stoichiometric amounts of 2-biphenylboronic acids and pyridine,which was further verified to be active for the catalytic system.The reactions proceeded under redox-neutral and air-tolerant conditions to produce a series of all-carbon six-membered rings with high efficiency.
基金We are grateful for financial support from the National Natural ScienceFoundation of China(Nos.21871112 and 21971090).
文摘Yne-allenes bearing both a C-C triple bond and an allene unit are a class of focal substrates in organic synthesis,in view of their structure diversity,.high reactivity and intermediate variety in the past years.Engaging yne-allenes in numerous annulation cascades provides efficient and direct accesses to elaborate functionalized polycyclic molecular architectures in a convergent manner.There are lots of types of catalytic chemical reactions such as intramolecular cyclizations,cycloisomerizations,intermolecular annulations,and bicyclizations as well as tricyclizations with the assistance of Lewis acids,Bronsted acids,bases,transition metals,and otherr c atalysts.This review provides an overview of the chemistry developed with transformations of yne-allenes by discussing their general and specific reactivities,presenting and commenting on their mechanisms as well as their applications.
基金Financial support from National Natural Science Foundation of China(No.21272237)the Ministry of Science and Technology of China(No.2011CB808600)the Chinese Academy of Sciences is gratefully acknowledged.
文摘Although the NHC-catalyzed cyclization reactions have been well established for the synthesis of various heterocycles,the corresponding all carbon cyclization reaction for the synthesis of carbocycles is far less established.In this note,the NHC-catalyzed all carbon[4+2]cyclocondensation of α,β-unsaturated acyl chlorides and 3-alkenyloxindoles was developed to give the corresponding spirocarbocyclic oxindoles in good yield with good to high diastereoselectivities.
基金We are grateful for financial support from the National Natural Science Foundation of China(Nos.21871112 and 21971090)the Science and Technology of Xuzhou(KC21022)。
文摘Molecular scaffolds endowed with all-carbon quaternary stereocenter are ubiquitous in natural products and significant bioactive molecules.However,efficient construction of this type of structure units is full of challenge due to their congested chemical envi-ronment.Herein,we report a new gold(Ⅰ)self-relay catalysis merging[3,3]-sigmatropic rearrangement/Nazarov cyclization with al-lylic alkylation starting from 1,3-enyne acetates and allylic alcohols,producing a wide range of synthetically important allyl cyclo-pentenones with an all-carbon quaternary stereocenter in good yields under mild conditions.This protocol demonstrates the precise control of regioselectivity,high functional group tolerance of substrates and the low loading of gold catalyst without inert atmos-phere protection,providing a catalytic and efficient entry to all-carbon quaternary stereocenters.
基金National Natural Science Foundation of China(Grant No.20672010)
文摘Nucleoside analogues show a variety of biological activities. To prepare new purine nucleoside analogues that could inhibit the proliferation of tumor cells and resist enzyrne hydrolysis, we designed and synthesized 15 different L-5＇noraristeromycin analogues, in which thioether, sulfoxide or sulfone function was introduced to replace the 5＇-hydroxymethyl group. Their anti-tumor activities were assayed in vitro. One compound showed potent anti-tumor activity.
文摘Concise and efficient three-component domino [4＋ 1 ＋ 1] carbocyclization to highly substituted fluoren-9-one derivatives promoted by K2CO3 has been developed under microwave irradiation conditions. The direct bis-cyanation and aryl amination residing in fluoren-9-one framework were achieved in a one-pot operation. The reaction proceeds at fast rates and can be finished within 30 min, which makes workup convenient to give good to excellent chemical yields.
