1375111-55-9Relevant academic research and scientific papers
Tunable arylative cyclization of 1,6-enynes triggered by rhodium(III)-catalyzed C-H activation
Fukui, Yuki,Liu, Ping,Liu, Qiang,He, Zhi-Tao,Wu, Nuo-Yi,Tian, Ping,Lin, Guo-Qiang
, p. 15607 - 15614 (2014)
Two tunable arylative cyclizations of cyclohexadienone-containing 1,6-enynes are reported via rhodium(III)-catalyzed C-H activation of O-substituted N-hydroxybenzamides. The use of different O substituents, i.e. O-Piv and O-Me, on the directing group allows the formation of either tetracyclic isoquinolones through an N-Michael addition process or hydrobenzofurans through a C-Michael addition process. Mechanistic investigations of these two cascade reactions clearly indicated that the C-H bond cleavage process was involved in the turnover-limiting step. Furthermore, the cyclization products could be subjected to various transformations for elaborating the pharmaceutically and synthetically valuable potential. This is the first example of a rhodium(III)-catalyzed arylative cyclization reaction of 1,6-enynes, and the results extend the application realm of CpRhIII-catalyzed C-H activation cascade reactions.
Silver(I)-catalyzed oxidative intramolecular cyclopropanation: Access to complex tricyclo[3.3.1.0]nonanediones via semipinacol-type rearrangement
Munakala, Anandarao,Gollapelli, Krishna Kumar,Nanubolu, Jagadeesh Babu,Chegondi, Rambabu
, p. 7019 - 7024 (2020)
An unconventional Ag(I)-catalyzed intramolecular cyclopropanation of prochiral alkyne-tethered cyclohexadienones has been developed using simple perchloric acid as an external oxidant. The transformation involves the formation of a perchloryloxy vinyl-silver species, which then proceeds through either intramolecular conjugate addition or an α-oxo silver carbene pathway to yield cyclopropane fused tricyclic enones with high diastereoselectivity. In the case of C-tethered cyclohexadienones, the reaction proceeds further via acid mediated semipinacol-type rearrangement to give complex and highly strained tricyclo[3.3.1.0]nonanediones. This cascade annulation has wide functional-group tolerance and broad substrate scope. Late-stage functionalization of estrone was also demonstrated with excellent diastereoselectivity.
Mn-catalyzed radical initiated domino transformation of alkynylated cyclohexadienones with TMSN3 and O2 to bicyclic azido alcohols
Pal, Pranesh,Mainkar, Prathama S.,Nayani, Kiranmai,Chandrasekhar, Srivari
, p. 3453 - 3456 (2020)
An efficient Mn-catalyzed cascade azide radical addition/cyclization/oxygen insertion reaction of alkyne-tethered cyclohexadienones with TMSN3 under mild conditions is reported. This domino reaction presents good diastereoselectivity generating bicyclic azido alcohol scaffolds which can be transformed into useful building blocks in organic synthesis for medicinal chemistry.
Catalytic, Regioselective Hydrocarbofunctionalization of Unactivated Alkenes Triggered by trans-Acetoxypalladation of Alkynes
Shukla, Rahul K.,Chaturvedi, Atul K.,Pal, Subir,Volla, Chandra M. R.
, p. 1440 - 1444 (2021)
Herein we demonstrate a Pd(II)-catalyzed regioselective hydrocarbofunctionalization of unactivated alkenes. The σ-vinyl-palladium(II) intermediate generated by the trans-acetoxypalladation of alkynes was added across carbon-carbon double bond to realize an efficient hydroalkenylation protocol. Bidentate auxiliary 8-aminoquinoline controls the regioselectivity of the carbopalladation step and thereby controls the regioselectivity of the hydroalkenylation. Additionally, when alkynes containing a hydroxy group at the three- or four-position were employed, the cascade sequence led to 1,6-dicarbonyl compounds via hydroalkenylation followed by intramolecular acyl migration.
Silver(I)-Catalyzed Enyne Cyclization/Aromatization of Alkyne-Tethered Cyclohexadienones to Access Meta-Substituted Phenols
Munakala, Anandarao,Chegondi, Rambabu
supporting information, p. 317 - 323 (2021/02/05)
Herein we report a highly regioselective silver(I)-catalyzed intramolecular annulation of alkyne-tethered cyclohexadienones to access meta-substituted phenols with enone functionality, which are difficult to synthesize from conventional methods. The reaction proceeds via intramolecular 1,6-enyne cyclization followed by aromatization and subsequent oxetene ring rearrangement. This strategy has also been compatible with a wide range of C-tethered cyclohexadienones to afford indanes in high yields. The unique functionality of products allows further transformations to expand the diversity.
Lewis Acid-Driven Meyer-Schuster-Type Rearrangement of Yne-Dienone
Mallick, Rajendra K.,Vangara, Srinivas,Kommu, Nagarjuna,Guntreddi, Tirumaleswararao,Sahoo, Akhila K.
, p. 7059 - 7068 (2021/05/29)
Developed herein is a Cu(II)-catalyzed Meyer-Schuster-type rearrangement of alkyne-tethered cyclohexadienone for the construction of m-enone-substituted phenols. The reaction involves an uncommon 5-exo-trig 1,6-enyne cyclization of alkyne-tethered-cyclohexadienone, aromatization-triggered C-O bond cleavage, and an electrocyclic 4π-ring-opening of oxetene intermediate. This atom-efficient transformation provides access to a wide range of synthetically important α-(m-substituted phenol)-α,β-unsaturated ketones, featuring a broad scope with labile functional group tolerance. The gram-scale demonstration makes this transformation synthetically viable. The synthetic application of α,β-unsaturated ketones is also showcased.
Palladium-catalyzed highly diastereoselective cascade dihalogenation of alkyne-Tethered cyclohexadienones: Via Umpolung of palladium enolate
Singh, Anurag,Shukla, Rahul K.,Volla, Chandra M.R.
supporting information, p. 13442 - 13445 (2019/11/14)
Herein, we report a highly diastereo-and regioselective dihalogenation of alkyne-Tethered cyclohexadienones for the synthesis of cis-hydrobenzofurans. One carbon-carbon and two carbon-halogen bonds were formed in an efficient manner and three contiguous s
Preparation method of 7-substituted-3,4,4,7-tetrahydrocyclobutane and coumarin-5-ketone
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Paragraph 0027-0029, (2019/04/10)
The invention discloses a preparation method of 7-substituted-3,4,4,7-tetrahydrocyclobutane and coumarin-5-ketone, and belongs to the field of organic synthesis. Propargyl alcohol and p-cresol are oxidized under the effect of iodobenzene acetate to obtain
Copper-catalyzed asymmetric silylative cyclization of cyclohexadienone-containing 1,6-enynes
He, Cheng-Yu,Xie, Li-Bo,Ding, Rui,Tian, Ping,Lin, Guo-Qiang
supporting information, p. 1682 - 1688 (2019/01/04)
The first copper-catalyzed asymmetric silylative cyclization of cyclohexadienone-containing 1,6-enynes has been accomplished through a tandem process: regioselective silylcupration of terminal unactivated alkynes and subsequently enantioselective conjugate addition to cyclohexadienones. This reaction proceeded smoothly to afford the cis-hydrobenzofuran and cis-hydroindole frameworks bearing two consecutive chiral carbon centers in high to excellent yields and moderate enantioselectivities. Additionally, the cyclization products could be readily subjected to several transformations for elaborating synthetic utilities.
Highly Enantioselective Rhodium-Catalyzed Cross-Addition of Silylacetylenes to Cyclohexadienone-Tethered Internal Alkynes
Duan, Chang-Lin,Tan, Yun-Xuan,Zhang, Jun-Li,Yang, Shiping,Dong, Han-Qing,Tian, Ping,Lin, Guo-Qiang
supporting information, p. 1690 - 1693 (2019/03/11)
The first highly enantioselective rhodium-catalyzed cross-addition of silylacetylenes to cyclohexadienone-tethered internal alkynes has been achieved via a tandem process: regioselective alkynylation of the internal alkynes and subsequent intramolecular conjugate addition to the cyclohexadienones, affording the cis-hydrobenzofuran frameworks with good yields (up to 88% yield) and excellent enantioselectivities (90%-96% ee). This mild reaction showed perfect atom economy and broad functional group tolerance. Furthermore, a gram-scale experiment and diverse further conversions of the cyclization products were also presented.
