ライフサイエンスコーパス: quaternary carbon

1 combination of a substituted heteroatom and quaternary carbon.

2 ction that establishes chirality at a remote quaternary carbon.

3 forming the five-membered ring including the quaternary carbon.

4 lenging reductive elimination that affords a quaternary carbon.

5 clobutanol to a spirocyclic indene bearing a quaternary carbon.

6 d products are formed with a new stereogenic quaternary carbon.

7 re obtained with Et(3)N for the migration of quaternary carbons.

8 involve the construction of two 1,3-related quaternary carbons.

9 the communesin relative configuration at the quaternary carbons.

10 ptors and products with newly formed vicinal quaternary carbons.

11 nactivated alkyl halides, yielding aliphatic quaternary carbons.

12 multiple stereocenters, including contiguous quaternary carbons.

13 ing complex carbon fragments and forming new quaternary carbons.

14 llowed for the enantioselective synthesis of quaternary carbons.

15 fragments with concomitant formation of new quaternary carbons.

16 om racemic nucleophiles to afford stereopure quaternary carbons.

17 diboron reagents to products that contain a quaternary carbon and a synthetically versatile carbon-b

18 hesis of chiral homoallylic amines bearing a quaternary carbon and an alkenylboron is disclosed.

19 Its tetracyclic skeleton contains three quaternary carbons and is marked by several syn-pentane

20 rds tricyclic indolizidines that incorporate quaternary carbons and up to five stereocenters with goo

21 ished three stereogenic centers, including a quaternary carbon, and proved highly scalable.

22 Quaternary carbons are established at high Fsp(3) attach

23 Quaternary carbons are ubiquitous in bioactive molecules

24 ks in HMBC that result from the highly dense quaternary carbons, as well as theoretical calculations.

25 For substrates with a quaternary carbon at that position, a carbocation interm

26 beta-Ketonitriles bearing a quaternary carbon at the 2-position were prepared throug

27 It was shown that NAs with a quaternary carbon at the alpha- or beta-position or a te

28 l with 2,3-butadienoates and amines having a quaternary carbon at the alpha-position.

29 cal cyclization to form the highly congested quaternary carbon at the center of these complex molecul

30 Alkenes bearing quaternary carbons at the allylic or homoallylic positio

31 an alkyl group that possesses a tertiary or quaternary carbon atom alpha to the carbon-zirconium bon

32 tes of esters, to form products containing a quaternary carbon atom at the nucleophile moiety and a t

33 of amphiphiles, each built around a central quaternary carbon atom derived from neopentyl glycol, wi

34 are heterocyclic amines possessing a chiral quaternary carbon atom in their heterocyclic ring.

35 ncorporating a cycloalkyl group linked via a quaternary carbon atom, with up to 40-fold increased pot

36 ontaining two or more contiguous stereogenic quaternary carbon atoms and key reactions in their total

37 ituted oxindoles have one or more asymmetric quaternary carbon atoms and they represent a large famil

38 t contain two or more contiguous stereogenic quaternary carbon atoms in their intricate structures ar

39 For otherwise difficult-to-measure quaternary carbon atoms, a SINO enhancement of up to 6 a

40 ter, complex ring structure, the presence of quaternary carbon atoms, and the low number of functiona

41 yl- and pivalyl-CoA, possessing tertiary and quaternary carbon atoms, respectively, are discussed.

42 [2 + 2] adducts with all-carbon-substituted quaternary carbon atoms.

43 ing a bond between two sterically encumbered quaternary carbon atoms.

44 ns of the conjugate addition products to key quaternary carbon-bearing synthetic building blocks proc

45 A quaternary carbon bears four other carbon substituents o

46 data suggest a high abundance of tetrahedral quaternary carbons bound to one oxygen and three carbon

47 ety of functionality can be installed at the quaternary carbon by using 1,2-disubstituted dienes.

48 enolate C-allylation to introduce the second quaternary carbon center (C8), and an azide reduction/N-

49 catalysis and their powerful applications in quaternary carbon center (QCC) formation.

50 g diversely decorated heterocycles contain a quaternary carbon center and this has been coursed throu

51 Allylboronates that bear a quaternary carbon center are air-stable and can be easil

52 Functionalized cyclopentanes containing a quaternary carbon center are derived from alkylidene oxi

53 ludes examples containing a bridgehead sp(3) quaternary carbon center as well as the cycloisomerizati

54 lds containing a prochiral dienone system, a quaternary carbon center connected to as many as four sp

55 a functionalized dienone system containing a quaternary carbon center connected to several sp(2) cent

56 omplexity of the chiral, fluorine-containing quaternary carbon center contained in GSK3335103.

57 intramolecular Heck reaction then forms the quaternary carbon center in an intermediate containing t

58 method was developed for the generation of a quaternary carbon center in carbonyl compounds.

59 Formation of the quaternary carbon center in citridone B is catalyzed by

60 give dihydroindolizines 8 and 9 possessing a quaternary carbon center in good yield.

61 bonds, two new stereogenic centers, and one quaternary carbon center in one single operation, which

62 r the stereoselective generation of a chiral quaternary carbon center in the alkaloid scaffold is int

63 resulting in the formation of a challenging quaternary carbon center is also described.

64 two lateral chains, each including a chiral quaternary carbon center with an ester moiety and a meth

65 red acyclic products embedding a methyl-aryl quaternary carbon center with up to 90% yield and 97:3 e

66 aring a contiguous tertiary carbon center, a quaternary carbon center, and a tertiary alcohol in the

67 eoselective nucleophilic substitution at the quaternary carbon center, with pure inversion of configu

68 s containing a diaryl-substituted all-carbon quaternary carbon center.

69 ective Giese radical addition to construct a quaternary carbon center.

70 crylate, which enables the introduction of a quaternary carbon center.

71 n of aldehydes along with the formation of a quaternary carbon center.

72 1,4-dicarbonyl constitution together with a quaternary carbon center.

73 selective synthesis of biologically relevant quaternary carbon-centered oxindoles.

74 ate a tetracyclic enamide bearing one of the quaternary carbon centers (C7) of the alkaloid, an intra

75 imary alcohols, including those bearing beta-quaternary carbon centers and beta-amino alcohols.

76 ther with the ability to forge N-substituted quaternary carbon centers and implement late-stage funct

77 Quaternary carbon centers are desirable targets for drug

78 onstructing richly functionalized all-carbon quaternary carbon centers at the beta-position of alipha

79 d be of great potential for the formation of quaternary carbon centers but often give poor yields/con

80 rst examples of the formation of stereogenic quaternary carbon centers by the Stille reaction; carbon

81 hly substituted cyclobutenes with contiguous quaternary carbon centers can be synthesized easily and

82 Tertiary and quaternary carbon centers containing allylic systems are

83 an unique platform for constructing diverse quaternary carbon centers containing heteroaryls which c

84 This approach to the synthesis of all-carbon quaternary carbon centers does not suffer from isomeriza

85 1,3-thiazolidine-2-thione scaffolds bearing quaternary carbon centers from carbon disulfide and alph

86 coupled products, including highly congested quaternary carbon centers from the corresponding tertiar

87 nown, their application in the generation of quaternary carbon centers in carbocyclic ring systems is

88 t access to the construction of tertiary and quaternary carbon centers in enantioselective fashion.

89 tion of hydroformylation to the synthesis of quaternary carbon centers is reported.

90 strategy for installation of the two vicinal quaternary carbon centers of the communesins is reported

91 yanates, toward thiazolidin-2-imines bearing quaternary carbon centers on the five-membered ring, in

92 required stereochemistry of the two adjacent quaternary carbon centers present in mersicarpine.

93 n patterns, the stereoselective synthesis of quaternary carbon centers remains a significant challeng

94 position and stereochemistry of the numerous quaternary carbon centers that are common to their tetra

95 tituted dihydroquinoxalin-2(1H)-ones bearing quaternary carbon centers under mild, visible-light phot

96 vinylation of various hydroxy-functionalized quaternary carbon centers using in situ generated isobut

97 and, Fro-DO, that promotes the generation of quaternary carbon centers via Ni-catalyzed Csp(3)-Csp(3)

98 variety of cyclobutylmethyl ketones bearing quaternary carbon centers was readily accessed without p

99 Using a Rh(I)/DPPF system, tertiary and quaternary carbon centers were formed with exclusively b

100 rt a biocatalytic method for the creation of quaternary carbon centers with broad substrate scope, le

101 Herein, we describe the formation of quaternary carbon centers with excellent diastereoselect

102 Michael acceptors was developed to introduce quaternary carbon centers with high regio- and diastereo

103 ides general access to sterically encumbered quaternary carbon centers, addressing a long-standing ch

104 oselective S(N)2' substitutions to construct quaternary carbon centers, and a one-pot reductive hydro

105 t the allylic position to forge tertiary and quaternary carbon centers.

106 tially valuable tool for the construction of quaternary carbon centers.

107 which provides imidazolidine frameworks with quaternary carbon centers.

108 ivatives with alpha-secondary, tertiary, and quaternary carbon centers.

109 ion of various chiral N-heterocycles bearing quaternary carbon centers.

110 s containing alpha-tertiary as well as alpha-quaternary carbon centers.

111 ubstrates containing alpha-tertiary or alpha-quaternary carbon centers.

112 for altered reactivity and the formation of quaternary carbon centers.

113 transformations forming tetrasubstituted and quaternary carbon centers.

114 a-heptadienes to afford cyclohexenes bearing quaternary carbon centers.

115 nct [4.2.1]-bicyclic skeleton containing two quaternary carbon centers.

116 azlactones containing adjacent tertiary and quaternary carbon centers.

117 ve configuration of spiroepoxides or related quaternary carbon-containing oxiranes can be troublesome

118 s inexpensive benzoic acid into 22 different quaternary carbon-containing phenanthridinone analogues

119 dary alcohols 3a-3u that incorporate acyclic quaternary carbon-containing stereodiads.

120 ces the synthetic burden to procure numerous quaternary carbon---containing products from simple chem

121 Observation of quaternary carbon epimerization via a retro-Mannich/Mann

122 mation is needed for enantioselectivity, and quaternary carbon formation is favored over tertiary.

123 ynthesis of trisubstituted alkenes bearing a quaternary carbon from internal alkynols and 2-pyrrolyl

124 (MHAT) has emerged as a useful tool to form quaternary carbons from alkenes via hydrofunctionalizati

125 enient method for the direct construction of quaternary carbons from tertiary alcohols by visible-lig

126 Here, we report the synthesis of quaternary carbons from tertiary alcohols, a class of st

127 ethod is that the resulting scaffold bearing quaternary carbon has been obtained through unusual [4 +

128 bstituted cyclohexanone ring system with two quaternary carbons, has been achieved in seven steps in

129 The congested nature of quaternary carbons hinders their preparation, most notab

130 tion of the polymer backbone in alkaline via quaternary carbon hydrolysis and ether hydrolysis, leadi

131 igh yields under mild conditions to form the quaternary carbon in alpha,alpha-disubstituted oxindoles

132 amma-aminomethyl-gamma-lactones containing a quaternary carbon in gamma-position are provided in high

133 barbituric acid derivatives with an in-ring quaternary carbon in unprecedented enantioselectivity, o

134 three new stereocenters and three continuous quaternary carbons in a single operation in high yield w

135 d densely substituted tropanes incorporating quaternary carbons in good yields and with high regio- a

136 ss beta,gamma-unsaturated ketones containing quaternary carbons in the alpha-position.

137 t years, a variety of cycloalkyl groups with quaternary carbons, in particular cyclopropyl and cyclob

138 The quaternary carbon is a predominant feature of natural pr

139 anocatalysis, the construction of asymmetric quaternary carbons is regarded as a challenging problem

140 l disconnection strategy targeting a central quaternary carbon locus.

141 hnson-Claisen rearrangement that generates a quaternary carbon next to a glucal-like oxygen.

142 th the known absolute stereochemistry at the quaternary carbon of spiciferone A, spicifernin, and ber

143 The preparation of the two epimers at the quaternary carbon of the 6-deoxy-C-altrose moiety in the

144 n, and nucleophilic addition constructs both quaternary carbons of the cyclooctane and four of the fi

145 The synthesis of quaternary carbons often requires numerous steps and com

146 ha carbon on the isocyanate moiety, either a quaternary carbon or a more flexible methylene group, co

147 od for the construction of boron-substituted quaternary carbons or diarylquaternary carbons by arylbo

148 The spirocyclic quaternary carbon positioned at the center of a bioactiv

149 ansfer and inverse gated decoupling suppress quaternary-carbon resonances, and T(1)-filtering reduces

150 eta-lactones and beta-lactones bearing alpha-quaternary carbons, respectively.

151 addition of a methyl group to generate a C-3 quaternary carbon resulted in acetamide 6, which showed

152 hanism for constructing congested quaternary-quaternary carbon(sp(3))-carbon(sp(3)) bonds in a pentan

153 The presence of a quaternary carbon stereocenter allows the exploration of

154 oxygenated fragments to form the critical C8 quaternary carbon stereocenter and set the stage for ela

155 functionalized beta-ketoesters containing a quaternary carbon stereocenter are obtained with up to 9

156 e fragments are coupled, and the critical C9-quaternary carbon stereocenter formed stereoselectively,

157 taining a hydroxyl substituent adjacent to a quaternary carbon stereocenter in the pyrrolidine ring.

158 taining a hydroxyl substituent adjacent to a quaternary carbon stereocenter is reported.

159 te a smooth nucleophilic substitution at the quaternary carbon stereocenter of stereodefined polysubs

160 omplex target structure is disconnected at a quaternary carbon stereocenter to fragments of comparabl

161 n allows the preparation of oxindoles with a quaternary carbon stereocenter using nonsymmetrical 1,2-

162 tionalized branched cyanoesters containing a quaternary carbon stereocenter with a vicinal tertiary s

163 ulfonyliminium ion cyclization to set the C3 quaternary carbon stereocenter, and assemble the diazatr

164 rings and four stereocenters, including one quaternary carbon stereocenter, has been developed.

165 ddition reaction that also generated the C11 quaternary carbon stereocenter.

166 2 reaction at a tertiary carbon to provide a quaternary carbon stereocenter.

167 nophosphonates and to phosphonates bearing a quaternary carbon stereocenter.

168 hallenging diquinanes containing two vicinal quaternary carbon stereocenters and multiple stereocente

169 Quaternary carbon stereocenters are a crucial component

170 The resultant quaternary carbon stereocenters are formed in high enant

171 tive methods for the construction of acyclic quaternary carbon stereocenters from achiral or chiral r

172 lop sp(3)-rich molecules, boosted utility of quaternary carbon stereocenters in bioactive compounds.

173 numerous asymmetric methods for formation of quaternary carbon stereocenters in cyclic systems have b

174 ubstituted hydroxylamines, the generation of quaternary carbon stereocenters through carbon-carbon co

175 e report a strategy that establishes acyclic quaternary carbon stereocenters through cross-coupling r

176 spective will inspire the chemist to utilize quaternary carbon stereocenters to enhance potency, sele

177 alkenylated, alkynylated and heteroarylated quaternary carbon stereocenters via 1,4-conjugate additi

178 been documented, the construction of acyclic quaternary carbon stereocenters with control of absolute

179 ketones to the enantioselective synthesis of quaternary carbon stereocenters would be highly valuable

180 Emphasis has been put on methods to create quaternary carbon stereocenters, including syntheses of

181 olecular frameworks containing newly created quaternary carbon stereocenters.

182 ivatives bearing one or multiple tertiary or quaternary carbon stereocenters.

183 ntio- and diastereoselective construction of quaternary carbon stereocenters.

184 tep constructions of molecules with multiple quaternary carbon stereocentres are rare.

185 Quaternary carbon stereocentres-carbon atoms to which fo

186 over four stereocentres, three of which are quaternary carbon stereocentres.

187 ry homoallylic alcohols containing a vicinal quaternary carbon stereogenic center and a versatile alk

188 ldehydes that bear an alpha-halo-substituted quaternary carbon stereogenic center as well as an assor

189 reagents and afford 1,4-dienes containing a quaternary carbon stereogenic center at their C-3 site,

190 generation of two new C-C bonds and one new quaternary carbon stereogenic center in a single synthet

191 d bicyclic amides that bear an N-substituted quaternary carbon stereogenic center.

192 d acyclic compounds bearing an N-substituted quaternary carbon stereogenic center.

193 lt-to-access vicinal beta-tertiary and gamma-quaternary carbon stereogenic centers and an alkenylboro

194 novel approach for the synthesis of acyclic quaternary carbon stereogenic centers and it represents

195 new approach toward the synthesis of acyclic quaternary carbon stereogenic centers and provides the f

196 nerate products containing boron-substituted quaternary carbon stereogenic centers are disclosed.

197 lboronates bearing B-substituted tertiary or quaternary carbon stereogenic centers are presented.

198 -6-aryltetrahydro-2H-pyran ring systems with quaternary carbon stereogenic centers.

199 responding trisubstituted alkenes, affording quaternary carbon stereogenic centers.

200 -2,8-dioxabicyclo[3.3.0]octanones containing quaternary carbon substituents at C6 is disclosed.

201 The nature of the substituent on the quaternary carbon thereby governs the product outcome du

202 e bulky hydrocarbon fragment is joined via a quaternary carbon to the highly hindered concave face of

203 t, three-component reaction in which one new quaternary carbon, two five-membered rings, one C-N bond

204 ven contiguous stereogenic centers including quaternary carbons up to two.

205 zyl (1,2-diarylethane) motif and challenging quaternary carbon variants.

206 een identified that promote the formation of quaternary carbons via Ni-catalyzed Csp(3)-Csp(3) cross-

207 Moreover, the introduction of a quaternary carbon was achieved by alkylation with ethyl

208 ss of highly strained molecules possessing a quaternary carbon with bonds that deviate from the canon

209 le to undergo nucleophilic ring opening at a quaternary carbon with complete inversion of the configu