ライフサイエンスコーパス: pinacol

1 he ferroceneboronate derivative of the diol, pinacol.

2 e the aerobic oxidative C-C bond cleavage of pinacol.

3 Treatment of the boronate with pinacol/acetic acid afforded the corresponding diol whic

4 end-capped with a triallylsilyl group and a pinacol arylboronate group was readily derived from diio

5 ed through the development of a novel hetero-pinacol-based macrocyclization cascade sequence.

6 Reaction of (tBuPOCOP)IrH2 with pinacol borane gave initially complex 2, which is assign

7 of the (tBuPOCOP)Ir core with a sigma-bound pinacol borane ligand in an approximately square planar

8 nexpensive and atom-economical boron source, pinacol borane, has been developed.

9 adily available 3-carbomethoxy-2-nitrophenyl pinacol boronate afforded the hindered highly functional

10 alyzed olefin cross-metathesis of 1-propenyl pinacol boronate and various alkenes, including function

11 droxyl functional group positioned beta to a pinacol boronate can serve to direct palladium-catalyzed

12 It is noted that the one-pot pinacol boronate cross-coupling reaction generally provi

13 A copper-promoted coupling of vinyl pinacol boronate esters and alcohols for the synthesis o

14 e protected to form synthetically ubiquitous pinacol boronate esters or used in situ in Suzuki-Miyaur

15 0 microM] were prepared via routes involving pinacol boronate esters, which were deprotected via a tw

16 y of functional groups, to the corresponding pinacol boronate esters.

17 rifluoroborate, neopentylglycolboronate, and pinacol boronate in nickel-catalyzed Suzuki-Miyaura cros

18 tiomeric excess with prior conversion of the pinacol boronate to the corresponding trifluoroborate sa

19 ctive Suzuki coupling of sterically hindered pinacol boronate with aryl iodide in the presence of mul

20 The direct amination of alkyl and aryl pinacol boronates is accomplished with lithiated methoxy

21 Functionalized vinyl pinacol boronates suitable for Suzuki cross-coupling rea

22 We found that addition of nBuLi to the pinacol boronic ester followed by trapping of the alkoxi

23 lalkanes that also incorporate an additional pinacol boronic ester which can be easily transformed to

24 A simple workup allows isolation of the pinacol boronic ester.

25 plexed lithiated carbamates with (Z)-alkenyl pinacol boronic esters and (E)-alkenyl neopentyl boronic

26 Allylic pinacol boronic esters are stable toward 1,3-borotropic

27 -Miyaura cross-coupling of the tosylates and pinacol boronic esters in the presence of a Pd(OAc)2/RuP

28 ly available, alpha-substituted allyl/crotyl pinacol boronic esters often give low E/Z selectivity (w

29 thodology for the protodeboronation of alkyl pinacol boronic esters that involves the formation of a

30 alpha,alpha-Disubstituted allylic pinacol boronic esters undergo highly selective allylbor

31 ation of acetophenone oxime ethers with aryl pinacol boronic esters, leading to the synthesis of biar

32 However, using pinacol boronic esters, the boron moiety migrates to the

33 and the previously unreported beta-methallyl pinacol boronic esters.

34 However, aryl boronic acid pinacol (BPin) ester reagents can be difficult coupling

35 stensibly equivalently reactive boronic acid pinacol (BPin) esters by kinetic discrimination during t

36 yl complex also underwent diastereoselective pinacol coupling (22:1 dr).

37 mportant C-C bond-forming reactions, such as pinacol coupling and McMurry chemistry, the mechanism of

38 lactonization; SmI2-mediated intramolecular pinacol coupling between ketone and lactone subunits to

39 arbonyl complexes were also prepared, though pinacol coupling of these substrates proceeded in, at be

40 pported acids enhance the selectivity of the pinacol coupling reaction compared with homogeneous acid

41 The first continuous flow pinacol coupling reaction of carbonyl compounds was succ

42 Vanadium-based pinacol coupling reactions were explored for closure of

43 Efficient pinacol coupling was developed in sole water, using a re

44 In these latter cases the pinacol coupling was diastereorandom.

45 It was found that the pinacol coupling, promoted by VCl(3) x (THF)(3)/Zn, proc

46 etones and aldehydes to give the products of pinacol coupling.

47 y and diastereoselectivity of intramolecular pinacol couplings on such substrates.

48 ed herein represent the first intramolecular pinacol couplings performed on the periphery of an iron(

49 All attempts at a pinacol cyclization or an intramolecular 6-exo-tet epoxi

50 e ketone alkylation and a diastereoselective pinacol cyclization.

51 uents are formed stereospecifically by Prins-pinacol cyclizations of unsaturated alpha-dithianyl acet

52 Several pinacol derivatives of podophyllotoxins bearing differen

53 on, and attempted alpha-deprotonation of the pinacol derived alkyl phosphonates resulted in ring clea

54 nts with the production of (18)F arenes from pinacol-derived aryl boronic esters (arylBPin) upon trea

55 vinyl appendage and a Takai olefination with pinacol dichloromethylboronate.

56 antioselective addition of allylboronic acid pinacol ester [allylB(pin)] to alpha,beta,gamma,delta-un

57 oss-coupling reaction with allylboronic acid pinacol ester and titanium assisted cross-metathesis (CM

58 utility of a 2-aminopyridine-5-boronic acid pinacol ester as a robust and versatile building block f

59 ross-coupling reactions of allylboronic acid pinacol ester derivatives with aryl and heteroaryl halid

60 m (S)-nicotine containing a C-4 boronic acid pinacol ester group.

61 Commercially available allenylboronic acid pinacol ester is used.

62 sp-Csp cross-coupling of alkynyl bromide and pinacol ester of alkynyl boronic acid catalyzed by CuFe2

63 ino-2,2':6',2''-terpyridine-6''-boronic acid pinacol ester) to promote directed Lewis acid/base inter

64 actions with unsubstituted allylboronic acid pinacol ester, additions to ketones with a mono- or a di

65 antioselective addition of allylboronic acid pinacol ester, allylB(pin), is described.

66 a Z- or an E-gamma-substituted boronic acid pinacol ester.

67 boronic ester (1,4-benzenediboronic acid bis(pinacol)ester).

68 (46-99%) from a variety of arylboronic acid pinacol esters and substituted o-allylbenzamides.

69 Aryl boronic acids or pinacol esters containing EDG were converted in good yie

70 cted diarylmethylamines and arylboronic acid pinacol esters has been achieved utilizing chiral mono-N

71 tosylate substrates using boronic acids and pinacol esters is reported.

72 veral common boronic acid derivatives (e.g., pinacol esters).

73 omologation of aryl and alkenyl boronic acid pinacol esters.

74 n of o-allylbenzamides with arylboronic acid pinacol esters.

75 The final step was thwarted by a pinacol-like rearrangement that delivered the unnatural

76 amides C (11) and D (12) through an apparent pinacol-like rearrangement.

77 Under pinacol-pinacolone conditions, vic-dihydroxy chlorins co

78 neral substituent migratory aptitudes in the pinacol-pinacolone rearrangement based on simple electro

79 f porphyrins with osmium tetraoxide, and the pinacol-pinacolone rearrangement of the resulting diols,

80 s among ketobacteriochlorins obtained in the pinacol-pinacolone rearrangements of vic-dihydroxybacter

81 rangement that is terminated by a thio-Prins-pinacol reaction is also identified.

82 Prins-pinacol reactions of these precursors promoted by SnCl4

83 Two new tandem cationic olefin cyclization-pinacol reactions that provide cyclopentane-fused cycloa

84 of BF(3).Et(2)O with 10a led to a novel aza-pinacol rearrangement and allylation at the alpha-carbon

85 this synthesis also employs an oxidation and pinacol rearrangement for the formation of the oxindole

86 The pivotal pinacol rearrangement is further examined through DFT ca

87 A recently developed aza-Prins-pinacol rearrangement was employed for the construction

88 The pinacol rearrangement, benzannulation, and oxy-Cope rear

89 tion, the acid-promoted (or catalyzed) Prins-pinacol rearrangement, with particular emphasis on its i

90 diphenylacetaldehyde (9) was generated via a Pinacol rearrangement.

91 A variety of competitive pinacol rearrangements and cyclization reactions were ov

92 lar routes described include EtMgBr-promoted pinacol ring expansions of hydroxy mesylates 23 and 34,

93 n the making, is loosely modeled after a key pinacol shift in the proposed biosynthesis.

94 Along with pinacols, some C-7 alkylidene and C-7 alkyl derivatives

95 he extraneous carbon introduced in the Prins-pinacol step; chemo- and stereoselective hydroxyl-direct

96 Key steps are as follows: (a) a pinacol-terminated 1,6-enyne cyclization reaction to for

97 nal illustrations of the uncommon utility of pinacol-terminated cationic cyclizations for the stereoc

98 During this study, a number of pinacol-terminated cationic cyclizations were examined t

99 on of the triple bond, carbocyclization, and pinacol-type 1,2-shift.

100 the A-ring with a subsequent SmI(2)-mediated pinacol-type coupling to reclose the A-ring following re

101 drofuran) subunit by a Lewis acid-catalyzed, pinacol-type rearrangement of an epoxy silyl ether.

102 Facile pinacol-type rearrangement of the alpha-hydroxycycloprop

103 ynthesis of 3-aryl-1-propenyl boronates from pinacol vinyl boronic ester and allyl-substituted aromat